[top]
000
FXUS62 KILM 212118
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
400 PM EST SAT NOV 21 2009
.SYNOPSIS...
INCREASING MOISTURE FROM THE GULF OF MEXICO WILL ENTER THE CAROLINAS
SUNDAY INTO MONDAY WITH WIDESPREAD RAIN EXPECTED. A BRIEF WARMUP IS
EXPECTED MID WEEK. A STRONG COLD FRONT THURSDAY WILL USHER IN
SOME COLDER AIR FOR NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 3 PM SATURDAY...MULTI-LAYERED CLOUDINESS IS INCREASING OVER
THE CAROLINAS FROM THE SOUTH AS AN UPPER TROUGH OVER LOUISIANA
ADVECTS GULF MOISTURE INTO THE AREA. ASIDE FROM SOME CLOUDS TRAPPED
UNDER A SUBSIDENCE INVERSION AROUND 800 MB...THE BULK OF THIS
MOISTURE IS AT AND ABOVE THE 500 MB LEVEL CURRENTLY. MODELS SHOW THE
DEPTH OF MOISTURE INCREASING THROUGH THE NIGHT AS SURFACE LOW
PRESSURE NEAR THE MOUTH OF THE MISSISSIPPI RIVER MOVES INTO SOUTHERN
ALABAMA LATE. THE 12Z RUNS OF THE NAM AND GFS SHOW MEASURABLE
PRECIPITATION SHOULD HOLD OFF UNTIL DURING THE DAY SUNDAY. THIS IDEA
IS SUPPORTED BY RECENT RADAR COMPOSITES SHOWING THE FRONT EDGE OF
THE PRECIPITATION EXTENDING NO FARTHER EAST THAN BILOXI MS
CURRENTLY.
LOW TEMPERATURES TONIGHT PRESENT AN INTERESTING PROBLEM. MOS
GUIDANCE SUGGESTS WE WILL REACH THE MID 40S IN MOST AREAS WHILE THE
RAW NAM AND GFS MODELS SHOW LOWS IN THE 50-55 RANGE. THE 12Z
CANADIAN IS IN BETWEEN THESE TWO EXTREMES. INSULATING INFLUENCE FROM
CLOUDS WILL BE PARTIALLY OFFSET BY WEAK COOL ADVECTION BELOW 850 MB.
OUR FORECAST IS FOR UPPER 40S INLAND AND AROUND 50 AT THE COAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...NEARLY ALL OF THE GUIDANCE HAS DELAYED ARRIVAL
OF THE PRECIP ON SUN...WITH LIGHT PRECIP NOW SPREADING OVER THE
SOUTHWEST PORTIONS OF THE FORECAST AREA SUN MORNING. LIGHT PRECIP
WILL CONTINUE TO SPREAD NORTH DURING THE AFTERNOON HOURS...COVERING
ALL OF THE AREA BY LATE AFTERNOON. HEAVIEST RAIN ARRIVES SUN NIGHT
INTO MON WITH INCREASE IN ISENTROPIC LIFT. DELAYED ARRIVAL OF
CATEGORICAL POPS TO ACCOUNT FOR SLOWER EVOLUTION OF THE SYSTEM.
LOW PRESSURE DEVELOPING OFF THE GA/SC COAST SUN NIGHT WILL TRACK
NORTHEAST...PASSING JUST EAST OF CAPE FEAR ON MON. FORECAST
SOUNDINGS AND CROSS SECTIONS SHOW PLENTY OF DRY AIR ABOVE 850 MB
SPREADING OVER THE AREA MON MORNING. SUBSIDENCE IN THE WAKE OF
EXITING LOW AND UPPER LEVEL SHORT WAVE COMBINED WITH DRY AIR WILL
BRING AN END TO MEASURABLE PRECIP. HAVE EXTENDED HIGHER POPS INTO
MON...BUT THINK MOST OF THE ACTION WILL BE OVER BY LATE MORNING.
AREA REMAINS UNDER THE INFLUENCE OF THE WEDGE FOR THE REMAINDER OF
MON AND THROUGH MON NIGHT WITH SOUTHWEST FLOW JUST ABOVE THE
SURFACE. WEAK OVERRUNNING WILL KEEP LOW CLOUD COVER IN PLACE WITH
SOME PATCHES OF DRIZZLE THROUGH THE AFTERNOON AND OVERNIGHT. AT THIS
POINT IT DOES NOT LOOK LIKE THIS BATCH OF PRECIP WILL MEASURE.
TEMPERATURES WILL REMAIN BELOW CLIMO DURING THE DAY...THOUGH COASTAL
SITE MAY FLIRT WITH CLIMO ON MON DEPENDING ON HOW CLOSE THE LOW
GETS TO THE COAST. CLOUD COVER AND MOISTURE WILL HELP KEEP OVERNIGHT
LOWS ABOVE TO WELL ABOVE CLIMO BOTH NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...WEAK HIGH PRESSURE WILL BE IN PLACE ACROSS
COASTAL CAROLINAS TUES THROUGH WED. PCP WATER VALUES WILL BE DOWN
CLOSER TO A HALF INCH WITH PLENTY OF DRY AIR ALOFT...BUT MOISTURE
PROFILES CONTINUE TO SHOW A VERY SHALLOW LAYER OF MOISTURE HOLDING
ON THROUGH WED MORNING. WITH SHALLOW COOL AIR IN PLACE AND DECENT
SUBSIDENCE AND DRY AIR IN PLACE ABOVE WILL HOLD ON TO LOW CLOUDS
THROUGH MUCH OF TUES. PATTERN REMAINS FAIRLY FLAT IN THE MID TO
UPPER LEVELS THROUGH MID WEEK UNTIL THURS INTO FRI WHEN MORE
SIGNIFICANT TROUGH APPROACHES AND MOVES THROUGH. DRIER WESTERLY FLOW
TAKES OVER THROUGH MID WEEK. A COLD FRONT OR PRE FRONTAL TROUGH
MOVES INTO THE COASTAL CAROLINAS LATE WED INTO THURS AS COASTAL
TROUGH DEVELOPS OFF THE SOUTHEAST COAST. LOOKING AT MID TO UPPER
LEVELS..MAY SEE A SHORTWAVE MOVE THROUGH LONGER WAVE H5 TROUGH
GIVING PUSH OF DRIER AIR INITIALLY...BUT THEN WINDS BACK ON THURS
TAPPING INTO A LITTLE GULF MOISTURE. THIS REMAINS MAINLY OFF
SHORE...BUT MAY BE JUST CLOSE ENOUGH TO PRODUCE SOME PCP FOR THURS
AFTN. THEREFORE WILL HOLD ONTO LOW END POPS FOR THURS. THEN PLENTY
OF DRY AIR WILL MOVE IN BEHIND STRONG COLD FRONT LATE THURS INTO
FRI. BY FRI HIGH AMPLITUDE MID TO UPPER TROUGH SWINGS ACROSS THE
EAST COAST SCOURING OUT ALL THE WEATHER AND BRINGING DRY AND COOL
HIGH PRESSURE FOR THE WEEKEND. MID TO UPPER LEVEL FLOW WILL REMAIN
MORE WESTERLY THROUGH FRI NIGHT BUT BY SAT AFTN SHOULD GET STRONGER
AND DEEPER LAYER COLD AIR STREAMING INTO THE CAROLINAS IN A DEEP
LAYER NW FLOW AS H5 TROUGH CLEARS THE COAST. EXPECT DRY BUT COLD
WEATHER THROUGH THE WEEKEND.
TEMPS WILL HOLD AROUND NORMAL OR ABOVE WITH SUNNIEST AND WARMEST DAY
EXPECTED ON WED. BY LATE THURS INTO FRI COLD AND DRY HIGH PRESSURE
WILL BUILD IN BEHIND STRONG COLD FRONTAL PASSAGE. 850 TEMPS DROP
BELOW 0C BY FRI EVENING AND WITH PLENTY OF DRY AIR IN PLACE...EXPECT
TEMPS DOWN IN THE 30S FOR OVERNIGHT LOWS BOTH FRI NIGHT AND SAT
NIGHT. DAY TIME HIGHS FRI AND SAT WILL BE BELOW NORMAL...BELOW 60
INLAND TO JUST NEAR 60 ALONG THE COAST.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
MID LEVEL STRATUS ASSOCIATED WITH WEAK LOW PRESSURE WAVE OFFSHORE IS
STRUGGLING TO ADVECT INLAND...AND COASTAL TERMINALS HAVE ONLY
REPORTED SCT CIGS TODAY. STILL EXPECT BKN 5K FOOT CIGS AT
ILM/CRE/MYR THROUGH THE AFTN AND INTO TONIGHT. FLO/LBT ONLY DEALING
WITH HIGH LEVEL CI STREAMING IN AHEAD OF DEVELOPING GULF OF MEXICO
LOW PRESSURE. WINDS HAVE BEEN GENERALLY OUT OF THE N/NE AT 8 TO 14
KT ACROSS THE REGION...AND THIS WILL CONTINUE THROUGH THE AFTN WHILE
INSOLATION HELPS PROMOTE MIXING. TONIGHT WINDS WILL DECREASE...BUT
LIKELY NOT DECOUPLE...SO EXPECT NE WINDS AT 4 TO 7 KT THROUGH THE
OVERNIGHT. NO FOG TONIGHT.
VFR WILL BE THE RULE AT ALL TERMINALS THROUGH THE TAF PERIOD. ONLY
FORECAST CONCERN WILL BE DEVELOPMENT OF RAIN TOMORROW AFTN. GUIDANCE
CONTINUES TO DELAY ONSET OF PRECIPITATION...SO HAVE ONLY INTRODUCED
VCSH TO FLO BY 18Z TOMORROW. ALL OTHER TERMINALS SHOULD REMAIN DRY
THROUGH THE NEXT 24 HOURS...WITH CEILINGS DEVELOPING AROUND 4K TO 5K
FEET EVERYWHERE. WILL LET FUTURE TAFS ADDRESS RAIN POTENTIAL AS THE
EVENT GETS CLOSER.
EXTENDED OUTLOOK...POTENTIAL IFR DUE TO SHOWERS AND LOW CEILINGS
SUNDAY AND MONDAY. FOG POSSIBLE TUESDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...A STATIONARY FRONT NEARLY 500 MILES OFF THE
CAROLINA COAST DEVELOPED A WEAK LOW PRESSURE CENTER EARLY THIS
MORNING. THIS LOW IS STILL OUT THERE ALTHOUGH ITS INFLUENCE ON OUR
WEATHER IS BECOMING SMALLER. ATTENTION IS NOW SHIFTING TO THE GULF
COAST WHERE A NEW LOW IS DEVELOPING OVER COASTAL LOUISIANA. THIS LOW
WILL MOVE EAST TO AROUND MOBILE AL BY DAYBREAK SUNDAY. THE PRESSURE
GRADIENT BETWEEN THIS LOW AND HIGH PRESSURE OVER NEW ENGLAND AND THE
EASTERN GREAT LAKES WILL KEEP A HEALTHY NE WIND BLOWING THROUGH THE
NIGHT INTO SUNDAY. WIND SPEEDS SHOULD AVERAGE 15-20 KT WITH SOME 25
KT GUSTS POSSIBLE...ESPECIALLY IN THE FRYING PAN SHOALS VICINITY.
OUTPUT FROM OUR LOCAL SWAN WAVE MODEL WAS ALMOST PERFECT ON
INITIALIZATION AND WILL BE USED FOR THE FORECAST TONIGHT. A SMALL
CRAFT ADVISORY WILL REMAIN POSTED FOR THE NC WATERS FOR 6 FT SEAS
OUT BEYOND 15 MILES FROM SHORE. WE WILL ALSO KEEP AN ADVISORY GOING
THROUGH THE EVENING SOUTH OF MURRELLS INLET UNTIL THE 6 FT SEAS DIE
AWAY THERE. ANY SIGNIFICANT RAINFALL SHOULD HOLD OFF UNTIL SOMETIME
DURING THE DAY SUNDAY.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...NORTHEAST FLOW CONTINUES THROUGH THE PERIOD
WITH SURFACE LOW PROGGED TO PASS EAST OF THE WATERS SUN NIGHT INTO
MON. PINCHED GRADIENT ON SUN WILL KEEP WINDS AROUND 20 KT WITH SEAS
4 TO 6 FT INTO SUN NIGHT. STRONGEST WINDS AND HIGHEST SEAS WILL BE
ACROSS NC WATERS...SO WILL CONTINUE SCA FOR ZONES 250 AND 252. WILL
LIKELY NEED A SCEC FOR SC ZONES WHEN THE TIME COMES. GRADIENT
RELAXES WHEN SURFACE LOW PASSES THE WATERS EARLY MON. HIGH PRESSURE
CONTINUES TO RIDGE DOWN THE EAST COAST AS THE LOW MOVES OFF TO THE
NORTHEAST ON MON...KEEPING LOW LEVEL FLOW OUT OF THE NORTH. LIGHTER
WINDS...10 TO 15 KT MON AND MON NIGHT...AND A SLIGHT OFFSHORE
COMPONENT WILL ALLOW SEAS TO FALL PRETTY QUICKLY...TO 2 TO 4 FT BY
MON EVENING.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...WEAK HIGH PRESSURE OVER WATERS THROUGH MID
WEEK WITH BENIGN WINDS AND SEAS EXPECTED. OVERALL EXPECT LIGHT OFF
SHORE FLOW 10 KTS OR LESS THROUGH EARLY THURS WITH SEAS LESS THAN 3
FT. BY THURS AFTN GRADIENT MAY INCREASE AS COLD FRONT PUSHES INTO
THE
CAROLINAS FROM THE WEST AND COASTAL TROUGH DEVELOPS TO THE SOUTH.
EXPECT WINDS AND SEAS TO INCREASE THROUGH LATE THURS INTO FRI AS
COLD FRONT APPROACHES AND MOVES THROUGH. MAY SEE SEAS UP NEAR 4 TO 5
FT IN OUTER WATERS IN STRONGER WESTERLY FLOW THURS NIGHT INTO FRI
MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR AMZ256.
SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR AMZ250-252.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...RGZ
AVIATION...JDW
[top]
000
FXUS62 KMHX 212100
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
400 PM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TONIGHT...THEN SLIDE
OFFSHORE ON SUNDAY. LOW PRESSURE WILL DEVELOP JUST OFFSHORE LATE
SUNDAY AND SUNDAY NIGHT...THEN LIFT NORTHEAST ON MONDAY. HIGH
PRESSURE WILL REBUILD OVER THE AREA TUESDAY AND WEDNESDAY. A COLD
FRONT WILL APPROACH FROM THE WEST ON THURSDAY AND MOVE OFFSHORE
FRIDAY. HIGH PRESSURE RETURNS TO THE AREA ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WEAK SHORT WAVE IS MOVING OFF THE SE COAST WITH ATTENDANT SFC
LOW WELL OFF THE SC COAST. ASSOCD PRECIP SHIELD EXTENDS NORTH TO
JUST OFF THE NC COAST BUT SHUD KEEP PUSHING OUT TO SEA AS THE
SHORT WAVE MOVES OFFSHORE. ALSO MODELS HAVE SLOWED DOWN ONSET OF
RAIN ASSOCD WITH THE GULF SYSTEM SO NO POPS IN FCST TNGT.
HIGH CLOUDS ASSOCD WITH THE LEAD SHORT WAVE AND ALSO WELL OUT
AHEAD NEXT SYSTEM MOVING THRU THE GULF COAST WILL AFFECT THE AREA
TONIGHT. THIS CLOUD COVER WILL BE THINNING OUT SOME AFTER THE
INITIAL SHORT WAVE MOVES OUT AND SHUD ALLOW TEMPS TO REACH INTO
MAINLY THE MID 40S INLAND TO THE LOWER 50S AT THE COAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
RAIN CHANCES WILL BE INCREASING ON SUNDAY AS INSENTROPIC LIFT
INCREASES FROM SOUTH TO NORTH OVER THE AREA. CSTL FRONT TAKES
SHAPE JUST OFFSHORE AHEAD OF APPROACHING SHORT WAVE. HAVE
CONTINUED TO SLOW DOWN/AND BACK OFF ON RAIN CHCS PARTICULARLY
EARLY IN THE DAY AS IT WILL TAKE SOME TIME FOR THE ATMOS TO
MOISTEN ENUF TO SUPPORT PCPN. SOME EARLY (BUT FILTERED) SUNSHINE
WILL AID TEMPERATURE RISE THRU MIDDAY SO MAY BE ABLE TO REACH TO
NEAR 60/LOWER 60S BEFORE THE THICKER CLOUDS AND PCPN SPREADS INTO
THE AREA DURING THE AFTN.
SUN NIGHT STILL LOOKS WET AS FORCING AND DEEP MOISTURE PEAK OVER
THE AREA. WILL CONTINUE TO HAVE CATEGORICAL POPS ALL AREAS SUN
NIGHT ALTHO IT MAY TAKE A WHILE FOR PCPN TO REACH FAR NE AREAS.
LOWS SUN NIGHT MAINLY IN THE 50S.
RAIN WILL GRADUALLY DIMINISH FROM S TO N MON AS MAIN AREA OF
ISENTROPIC LIFT MOVES INTO VA. HOWEVER EXPECT THERE WILL STILL
BE A GOOD COVERAGE OF RAIN THROUGH MUCH OF THE MORNING HOURS
BEFORE TAPERING OFF DURING THE AFTN. FCST QPF AMOUNTS HAVE
INCREASED A BIT WITH GENERALLY BETWEEN .75 AND 1.25 INCHES WITH
THE HIGHER AMOUNTS CLOSER TO THE COAST. THE MONDAY MORN COMMUTE
WILL BE AFFECTED WITH WET ROADS AND PUDDLING BUT THIS RAINFALL
SHUD NOT RESULT IN ANY SIGNIFICANT FLOOD PROBLEMS AS THIS IS A
FAIRLY QUICK HITTING EVENT. TRACK OF THE LOW CLOSER TO THE COAST
MAY DRAW IN SOME OCEAN WARMTH ALLOWING TEMPS ON MONDAY TO REACH
THE UPPER 50S AND LOWER 60S DESPITE THE RAIN.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ANY LINGERING LIGHT RAIN/DRIZZLE WILL END MON NIGHT BUT LATEST
GUIDANCE SUGGS CLOUDS MAY BE SLOW TO CLEAR ON TUE DUE TO RESIDUAL
LOW LEVEL MOISTURE. HAVE GONE MORE PESSIMISTIC WITH CLOUD COVER
AND LOWERED MAX TEMPS ON TUE GIVEN THE EXPECTED LIMITED SUNSHINE.
SHUD STILL BE ABLE TO ECK OUT A NICE DAY WED (WITH HIGHS IN THE
MID TO UPPER 60S) BEFORE CLOUDS AND PCPN ASSOCD WITH THE NEXT
SYSTEM APPROACH THE AREA.
A SOLN CLOSER TO THE OPERATIONAL ECMWF CONTINUES TO BE PREFERRED
FOR THE SYSTEM TO AFFECT THE AREA ON THANKSGIVING. A SOUTHERN
STREAM SFC LOW SHUD PASS CLOSE ENOUGH TO THE COAST TO PROVIDE THE
AREA WITH DECENT PCPN CHCS (ESP NEAR THE COAST) LATER WED NIGHT
AND THRU THANKSGIVING. THIS SYSTEM SHUD MOVE OUT FAIRLY QUICKLY
AS A STRONG NORTHERN STREAM SHORT WAVE FOLLOWS CLOSELY ON ITS
HEELS THU NIGHT. EXPECT THE LATE WEEK AND EARLY WEEKND TO BE DRY
AND COOL AS STRONG HIGH PRES BUILDS IN FROM THE NORTHWEST.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AS OF 2 PM SAT...GFS LAMP AND NAM GUIDANCE CONTINUES TO SLOW DOWN
THE PROGRESSION OF THE MOISTURE INTO THE REGION...AND GENERAL LACK
OF SUPPORT FOR MUCH CLOUD DEVELOPMENT. HAVE GONE A BIT FASTER
BRINGING IN THE MID DECK OVERNIGHT WITH CLOUDS DROPPING INTO SUN
AS THE RAIN ADVANCES ON THE REGION. THE RAIN WILL MOVE IN LATE SUN
INTO MON...WITH LOW CLOUDS EXP TO LINGER POTENTIALLY INTO TUE.
HIGH PRES WILL BUILD OVER THE REGION THEREAFTER...WITH CLEARING
AND PREDOMINANT VFR CONDITIONS. HOWEVER HIGHER TD COULD LEAD TO
OVERNIGHT FOG OR STRATUS DEVELOPMENT TUE NT AND WED NT.
&&
.MARINE...
AS OF 2 PM SAT...THE WEAK LOW OFFSHORE AND HIGH PRES TO OUR N
IS PRODUCING WINDS 20-25KT WINDS MAINLY S OF OREGON INLET. SEAS
HAVE BOUNCED AROUND 5 TO 8 FT THIS AFT...WITH CONDITIONS EXP TO
CHANGE LITTLE THIS EVENING. LATER TNT AS THE LOW MOVES E WE WILL
SEE AN IMPROVEMENT IN WINDS...THOUGH SEAS WILL REMAIN UP ESP
SOUTH. MEANWHILE...SATELLITE SHOWS A CLEARLY DEFINED LOW OVER THE
GULF STATES WHICH WILL MOVE E SUN AND OVER THE CAROLINAS BY MON.
THE LOW IS EXP TO REMAIN POORLY ORGANIZED AS UPPER LVL SUPPORT
WEAKENS. THE TRACK OF THIS WEAK SYSTEM WILL MOVE NEAR OR OVER
HATTERAS...WHICH WILL KEEP THE LIGHTEST WINDS OVER THIS REGION.
HOWEVER THE SE WINDS AHEAD AND BEHIND THE LOW COULD BRIEFLY GUST
TO SMALL CRAFT. THE N WATERS WILL LIKELY REMAIN AROUND 20KT AS THE
LOW PASSES TO THE S. THE SEAS WILL REMAIN ABV SCA THROUGH OUT MON
NT.
BY MON THE STRONG HIGH OVER NEW ENGLAND WILL SLIDE E OFFSHORE.
MEANWHILE AN AREA OF LOW PRES NEAR 50W WILL PINCH THE GRAD AND
COMBINED WITH SOME HIGHER SEAS OVER THE N ATLANTIC WILL PRODUCE
SOME DOUBLE DIGIT SEAS. THE ENE FETCH AROUND THE HIGH WILL STEER A
LOT OF THIS ENERGY TOWARDS THE E COAST...AND THOUGH IT WILL
DIMINISH GREATLY BEFORE IT REACHES THE COAST IT COULD ADD SOME
SWELL TO THE SEA HEIGHTS TO THE LOCAL WATERS EARLY TO MID WEEK.
THE HIGH PRES SLIDING OVER THE REGION WILL AID IN DROPPING WIND
SPEEDS SO COMBINED SEAS COULD DROP BELOW 6FT DURING THIS
TIME...HOWEVER N WATERS COULD REMAIN UP THROUGH THE REST OF THE
FCST IF WAVEWATCH SEAS WERE ACCURATE. DUE TO LIMITED OBSERVATIONS
OVER THAT PART OF THE ATLANTIC CAN`T VERIFY THE INITIAL CONDITIONS
OF WAVEWATCH...SO HAVE SHAVED ABOUT A FOOT OFF THE OUTPUT BY
TUE/WED UNTIL THERE IS MORE SUPPORT OF THIS LONG PERIOD SWELL. A
CLOSED UPPER LOW DIGGING OUT OF THE GREAT LAKES REGION COULD LEAD
TO CYCLOGENESIS OFF THE MID ATLANTIC COAST BY THU. MOST MODELS
SUPPORT A WEAK LOW PASSING OBX AND STRENGTHENING AT IS MOVES
TOWARDS NEW ENGLAND...WITH THE CANADIAN BEING THE STRONGEST
SOLUTIONS OF A COASTAL LOW SKIRTING NC. WITH THE UPPER SUPPORT
BEING MUCH FURTHER N THAN OUR LAST COASTAL LOW...FEEL THE WEAKER
SOLUTIONS HERE ARE MORE LIKELY. HOWEVER...THE CAA ON THE BACKSIDE
OF THE LOW THU NT INTO FRI WILL INCREASE TO SCA IN STRONG NW
WINDS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...BTC
NEAR TERM...BTC
SHORT TERM...BTC
LONG TERM...BTC
AVIATION...SJ
MARINE...SJ
000
FXUS62 KILM 212001
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
301 PM EST SAT NOV 21 2009
.SYNOPSIS...
INCREASING MOISTURE FROM THE GULF OF MEXICO WILL ENTER THE CAROLINAS
SUNDAY INTO MONDAY WITH WIDESPREAD RAIN EXPECTED. A BRIEF WARMUP IS
EXPECTED MID WEEK. A STRONG COLD FRONT THURSDAY WILL USHER IN
SOME COLDER AIR FOR NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 3 PM SATURDAY...MULTI-LAYERED CLOUDINESS IS INCREASING OVER THE
CAROLINAS FROM THE SOUTH AS AN UPPER TROUGH OVER LOUISIANA ADVECTS
GULF MOISTURE INTO THE AREA. ASIDE FROM SOME CLOUDS TRAPPED UNDER A
SUBSIDENCE INVERSION AROUND 800 MB...THE BULK OF THIS MOISTURE IS AT
AND ABOVE THE 500 MB LEVEL CURRENTLY. MODELS SHOW THE DEPTH OF
MOISTURE INCREASING THROUGH THE NIGHT AS SURFACE LOW PRESSURE NEAR
THE MOUTH OF THE MISSISSIPPI RIVER MOVES INTO SOUTHERN ALABAMA LATE.
THE 12Z RUNS OF THE NAM AND GFS SHOW MEASURABLE PRECIPITATION SHOULD
HOLD OFF UNTIL DURING THE DAY SUNDAY. THIS IDEA IS SUPPORTED BY
RECENT RADAR COMPOSITES SHOWING THE FRONT EDGE OF THE PRECIPITATION
EXTENDING NO FARTHER EAST THAN BILOXI MS CURRENTLY.
LOW TEMPERATURES TONIGHT PRESENT AN INTERESTING PROBLEM. MOS
GUIDANCE SUGGESTS WE WILL REACH THE MID 40S IN MOST AREAS WHILE THE
RAW NAM AND GFS MODELS SHOW LOWS IN THE 50-55 RANGE. THE 12Z
CANADIAN IS IN BETWEEN THESE TWO EXTREMES. INSULATING INFLUENCE FROM
CLOUDS WILL BE PARTIALLY OFFSET BY WEAK COOL ADVECTION BELOW 850 MB.
OUR FORECAST IS FOR UPPER 40S INLAND AND AROUND 50 AT THE COAST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...NEARLY ALL OF THE GUIDANCE HAS DELAYED ARRIVAL
OF THE PRECIP ON SUN...WITH LIGHT PRECIP NOW SPREADING OVER THE
SOUTHWEST PORTIONS OF THE FORECAST AREA SUN MORNING. LIGHT PRECIP
WILL CONTINUE TO SPREAD NORTH DURING THE AFTERNOON HOURS...COVERING
ALL OF THE AREA BY LATE AFTERNOON. HEAVIEST RAIN ARRIVES SUN NIGHT
INTO MON WITH INCREASE IN ISENTROPIC LIFT. DELAYED ARRIVAL OF
CATEGORICAL POPS TO ACCOUNT FOR SLOWER EVOLUTION OF THE SYSTEM.
LOW PRESSURE DEVELOPING OFF THE GA/SC COAST SUN NIGHT WILL TRACK
NORTHEAST...PASSING JUST EAST OF CAPE FEAR ON MON. FORECAST
SOUNDINGS AND CROSS SECTIONS SHOW PLENTY OF DRY AIR ABOVE 850 MB
SPREADING OVER THE AREA MON MORNING. SUBSIDENCE IN THE WAKE OF
EXITING LOW AND UPPER LEVEL SHORT WAVE COMBINED WITH DRY AIR WILL
BRING AN END TO MEASURABLE PRECIP. HAVE EXTENDED HIGHER POPS INTO
MON...BUT THINK MOST OF THE ACTION WILL BE OVER BY LATE MORNING.
AREA REMAINS UNDER THE INFLUENCE OF THE WEDGE FOR THE REMAINDER OF
MON AND THROUGH MON NIGHT WITH SOUTHWEST FLOW JUST ABOVE THE
SURFACE. WEAK OVERRUNNING WILL KEEP LOW CLOUD COVER IN PLACE WITH
SOME PATCHES OF DRIZZLE THROUGH THE AFTERNOON AND OVERNIGHT. AT THIS
POINT IT DOES NOT LOOK LIKE THIS BATCH OF PRECIP WILL MEASURE.
TEMPERATURES WILL REMAIN BELOW CLIMO DURING THE DAY...THOUGH COASTAL
SITE MAY FLIRT WITH CLIMO ON MON DEPENDING ON HOW CLOSE THE LOW
GETS TO THE COAST. CLOUD COVER AND MOISTURE WILL HELP KEEP OVERNIGHT
LOWS ABOVE TO WELL ABOVE CLIMO BOTH NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 AM SATURDAY...A WEAK UPPER RIDGE MANAGES TO BUILD ON
TUESDAY AND THIS SHOULD BRING A MILD AFTERNOON. WEDNESDAY MAY ALSO
BRING HIGHS IN THE LOW 70S AHEAD OF WHAT WILL END UP BEING A
PRETTY STRONG COLD FRONT ON THURSDAY. LITTLE TO NO MOISTURE FLOW
AHEAD OF THE FRONT SO ITS PASSAGE SHOULD BE DRY. THE ECWMF HAS
INDICATED OTHERWISE FOR A FEW RUNS NOW BUT THIS MODEL HAS BEEN
DISPLAYING A VERY WET BIAS FOR SOME TIME LOCALLY IN SUCH SETUPS.
DRY AND COOL WEATHER FOR THE REST OF THE PD WITH HIGHS STRUGGLING
TO LOW 60S BY DAY AND UPPER 30S AT NIGHT.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
MID LEVEL STRATUS ASSOCIATED WITH WEAK LOW PRESSURE WAVE OFFSHORE IS
STRUGGLING TO ADVECT INLAND...AND COASTAL TERMINALS HAVE ONLY
REPORTED SCT CIGS TODAY. STILL EXPECT BKN 5K FOOT CIGS AT
ILM/CRE/MYR THROUGH THE AFTN AND INTO TONIGHT. FLO/LBT ONLY DEALING
WITH HIGH LEVEL CI STREAMING IN AHEAD OF DEVELOPING GULF OF MEXICO
LOW PRESSURE. WINDS HAVE BEEN GENERALLY OUT OF THE N/NE AT 8 TO 14
KT ACROSS THE REGION...AND THIS WILL CONTINUE THROUGH THE AFTN WHILE
INSOLATION HELPS PROMOTE MIXING. TONIGHT WINDS WILL DECREASE...BUT
LIKELY NOT DECOUPLE...SO EXPECT NE WINDS AT 4 TO 7 KT THROUGH THE
OVERNIGHT. NO FOG TONIGHT.
VFR WILL BE THE RULE AT ALL TERMINALS THROUGH THE TAF PERIOD. ONLY
FORECAST CONCERN WILL BE DEVELOPMENT OF RAIN TOMORROW AFTN. GUIDANCE
CONTINUES TO DELAY ONSET OF PRECIPITATION...SO HAVE ONLY INTRODUCED
VCSH TO FLO BY 18Z TOMORROW. ALL OTHER TERMINALS SHOULD REMAIN DRY
THROUGH THE NEXT 24 HOURS...WITH CEILINGS DEVELOPING AROUND 4K TO 5K
FEET EVERYWHERE. WILL LET FUTURE TAFS ADDRESS RAIN POTENTIAL AS THE
EVENT GETS CLOSER.
EXTENDED OUTLOOK...POTENTIAL IFR DUE TO SHOWERS AND LOW CEILINGS
SUNDAY AND MONDAY. FOG POSSIBLE TUESDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...A STATIONARY FRONT NEARLY 500 MILES OFF THE
CAROLINA COAST DEVELOPED A WEAK LOW PRESSURE CENTER EARLY THIS
MORNING. THIS LOW IS STILL OUT THERE ALTHOUGH ITS INFLUENCE ON OUR
WEATHER IS BECOMING SMALLER. ATTENTION IS NOW SHIFTING TO THE GULF
COAST WHERE A NEW LOW IS DEVELOPING OVER COASTAL LOUISIANA. THIS LOW
WILL MOVE EAST TO AROUND MOBILE AL BY DAYBREAK SUNDAY. THE PRESSURE
GRADIENT BETWEEN THIS LOW AND HIGH PRESSURE OVER NEW ENGLAND AND THE
EASTERN GREAT LAKES WILL KEEP A HEALTHY NE WIND BLOWING THROUGH THE
NIGHT INTO SUNDAY. WIND SPEEDS SHOULD AVERAGE 15-20 KT WITH SOME 25
KT GUSTS POSSIBLE...ESPECIALLY IN THE FRYING PAN SHOALS VICINITY.
OUTPUT FROM OUR LOCAL SWAN WAVE MODEL WAS ALMOST PERFECT ON
INITIALIZATION AND WILL BE USED FOR THE FORECAST TONIGHT. A SMALL
CRAFT ADVISORY WILL REMAIN POSTED FOR THE NC WATERS FOR 6 FT SEAS
OUT BEYOND 15 MILES FROM SHORE. WE WILL ALSO KEEP AN ADVISORY GOING
THROUGH THE EVENING SOUTH OF MURRELLS INLET UNTIL THE 6 FT SEAS DIE
AWAY THERE. ANY SIGNIFICANT RAINFALL SHOULD HOLD OFF UNTIL SOMETIME
DURING THE DAY SUNDAY.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...NORTHEAST FLOW CONTINUES THROUGH THE PERIOD
WITH SURFACE LOW PROGGED TO PASS EAST OF THE WATERS SUN NIGHT INTO
MON. PINCHED GRADIENT ON SUN WILL KEEP WINDS AROUND 20 KT WITH SEAS
4 TO 6 FT INTO SUN NIGHT. STRONGEST WINDS AND HIGHEST SEAS WILL BE
ACROSS NC WATERS...SO WILL CONTINUE SCA FOR ZONES 250 AND 252. WILL
LIKELY NEED A SCEC FOR SC ZONES WHEN THE TIME COMES. GRADIENT
RELAXES WHEN SURFACE LOW PASSES THE WATERS EARLY MON. HIGH PRESSURE
CONTINUES TO RIDGE DOWN THE EAST COAST AS THE LOW MOVES OFF TO THE
NORTHEAST ON MON...KEEPING LOW LEVEL FLOW OUT OF THE NORTH. LIGHTER
WINDS...10 TO 15 KT MON AND MON NIGHT...AND A SLIGHT OFFSHORE
COMPONENT WILL ALLOW SEAS TO FALL PRETTY QUICKLY...TO 2 TO 4 FT BY
MON EVENING.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...LOOKS LIKE A FAIRLY QUIET PATTERN FOR MOST
OF THE PERIOD. HIGH PRESSURE REMAINS TO THE NORTH TUESDAY BRINGING
A LIGHT NORTHERLY WIND AND SEAS IN THE 2 TO 3 FT RANGE. CHANGES
MAY BE UNDERWAY COME WEDNESDAY AS THE HIGH BEGINS TO LIFT OUT
AHEAD OF AN APPROACHING COLD FRONT. THE TIMING OF THIS FRONT AND
THE EVOLUTION OF SURFACE FEATURES ASSOCIATED WITH IT IS HIGHLY
UNCERTAIN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR AMZ256.
SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR AMZ250-252.
&&
$$
NEAR TERM...TRA
SHORT TERM...III
LONG TERM...MBB
AVIATION...JDW
[top]
000
FXUS62 KRAH 211943
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
240 PM EST SAT NOV 21 2009
.SYNOPSIS...
A LOW PRESSURE SYSTEM IN THE NORTHWEST GULF OF MEXICO WILL MOVE
SLOWLY NORTHEAST TOWARD THE FLORIDA GULF COAST TONIGHT...BEFORE
WEAKENING AND REFORMING ALONG THE CAROLINA COAST SUNDAY NIGHT. THIS
WILL BRING INCREASING CLOUD COVER AND A GOOD CHANCE OF RAIN TO
CENTRAL NORTH CAROLINA BY SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 1200 PM SATURDAY...
16Z SFC ANALYSIS SHOWED 1024 MB HIGH PRESSURE CENTERED OVER OH/WV.
1010 MB LOW PRESSURE WAS CENTERED NEAR BUOY 42361 SOUTH OF LA.
ALOFT...12Z RAOB ANALYSIS SHOWED A SPLIT FLOW PATTERN ACROSS THE
CONUS. A SOUTHERN STREAM 500 MB LOW WAS CENTERED OVER SOUTHEAST TX.
A 90 KT SOUTHERN STREAM JET WAS NOTED ALONG THE SOUTHERN PERIPHERY
OF THE UPPER LOW OVER NORTHERN MEXICO AND THE NORTHERN GOMEX. A 100
KT NORTHERN STREAM JET WAS NOTED OVER THE NORTHERN MID-ATLANTIC
AHEAD OF A DEAMPLIFYING NORTHERN STREAM TROUGH OVER THE LOWER GREAT
LAKES. A RIDGE ALOFT WAS PRESENT OVER THE CENTRAL AND NORTHERN GREAT
PLAINS.
TODAY:
THE UPPER LOW CURRENTLY OVER SOUTHEAST TX IS PROGGED TO MOVE ENE
INTO LA BY 00Z THIS EVENING...WHILE THE ASSOC SFC LOW CURRENTLY OVER
THE NORTHWEST GOMEX IS PROGGED TO BE LOCATED JUST SOUTH OF THE LA
COAST BY THAT TIME. SFC HIGH PRESSURE IS EXPECTED TO REMAIN CENTERED
OVER PORTIONS OF THE MID-ATLANTIC...LOWER GREAT LAKES AND OH VALLEY
IN ASSOC/W CONFLUENT FLOW ALOFT...WITH A SFC RIDGE AXIS EXTENDING
SOUTH INTO THE CAROLINAS. EXPECT A STEADY INFLUX OF MID/UPPER LEVEL
CLOUD COVER THROUGHOUT THE DAY TODAY AS MOISTURE MOVES DOWNSTREAM OF
THE UPPER LOW ALONG THE GULF COAST INTO THE SOUTHEAST STATES AND
CAROLINAS. MOISTURE ADVECTION WILL GENERALLY BE LIMITED TO THE UPPER
LEVELS TODAY...AND CLOUD BASES WILL REMAIN AOA 15-18 KFT. LIFT TODAY
WILL BE EITHER VERY WEAK OR NON-EXISTENT ACROSS CENTRAL NC. ALTHOUGH
THERE IS CURRENTLY A NORTHERN STREAM JET ENTRANCE REGION N/NW OF
CENTRAL NC...THIS FEATURE IS PROGGED TO WEAKEN AND LIFT NORTHEAST
AWAY FROM THE AREA. MODEL ISENTROPIC FIELDS DO INDICATE INCREASING
ISENTROPIC LIFT ACROSS THE SOUTHEAST STATES THIS AFT/EVE AS A
925-850 MB WARM FRONT MOVES NORTHWARD TOWARD THE CENTRAL GULF COAST
AHEAD OF THE SFC/UPPER LOW IN LA. HOWEVER...ISENTROPIC LIFT WILL BE
WEAK AND CONFINED WELL SOUTH/SW OF CENTRAL NC. AS A RESULT...EXPECT
NO CHANCE FOR PRECIP THIS AFT/EVE. HIGH TEMPS WILL BE COMPLICATED
PRIMARILY BY BROKEN SKIES ASSOC/W UPPER LEVEL CLOUD COVER.
THICKNESSES WOULD ARGUE FOR HIGHS IN THE ~63F RANGE WITH FULL SUN...
HOWEVER...GIVEN WEAK LOW LEVEL NORTHEAST FLOW AND BROKEN UPPER LEVEL
CLOUD COVER...A RANGE OF 60-63F LOOKS MORE REASONABLE...ALTHOUGH
EVEN THAT COULD BE WARM BY 1-2F DEPENDING ON THE OPACITY OF CLOUD
COVER.
TONIGHT:
THE UPPER LOW CURRENTLY OVER SOUTHEAST TX IS PROGGED TO DEAMPLIFY
TONIGHT AS IT MOVES SLOWLY ENE INTO THE DEEP SOUTH. THE ATTENDANT
SFC LOW IS ALSO PROGGED TO WEAKEN A FEW MILLIBARS AS IT MOVES ALONG
A BAROCLINIC ZONE LOCATED OVER THE CENTRAL/NORTHEAST GULF COAST.
DESPITE THE WEAKENING SOUTHERN STREAM DYNAMICS...ISENTROPIC LIFT IS
EXPECTED TO STRENGTHEN OVER THE SOUTHEAST STATES INTO THE SOUTHERN
CAROLINAS TONIGHT AS A 925-850 MB WARM FRONT LIFTS NORTHWARD INTO
AL/GA AHEAD OF THE LOW PRESSURE SYSTEM ALONG THE GULF COAST. THE
BEST LOW LEVEL MOISTURE AND ISENTROPIC LIFT IS EXPECTED TO REMAIN
WELL S/SW OF CENTRAL NC THROUGH 12Z SUN...WITH PRECIP CHANCES
LARGELY CONFINED TO AL/GA AND PERHAPS SOUTHERN/WESTERN PORTIONS OF
SC. AS A RESULT...EXPECT A DRY FORECAST TO CONTINUE THROUGH THE
OVERNIGHT HOURS. MID/UPPER LEVEL CLOUD COVER WILL BE PERVASIVE
ACROSS THE AREA TONIGHT IN ASSOC/W THE LOW PRESSURE SYSTEM UPSTREAM
OF THE AREA...AND THAT WILL BE THE PRIMARY COMPLICATING FACTOR
W/REGARD TO LOW TEMPS. A MOS GUIDANCE BLEND LOOKS PRETTY
REASONABLE...WITH LOWS IN THE LOWER/MID 40S.
SUNDAY:
LATEST 12Z MODEL GUIDANCE CONTINUES TO SHOW THE 500 MB LOW
DEAMPLIFYING INTO A SHORTWAVE DURING THE DAY SUNDAY AS IT MOVES N/NE
INTO NORTHERN AL/GA AND EASTERN TN. THE ATTENDANT GULF COAST SFC LOW
IS PROGGED TO WEAKEN AS IT REMAINS CENTERED NEAR THE FL/AL COAST. AN
INVERTED SFC TROUGH/COASTAL FRONT IS EXPECTED TO SHARPEN OFF THE
SOUTHEAST/CAROLINA COAST DURING THE DAY SUN IN ASSOC/W WEAK UPPER
FORCING ASSOC/W THE DEAMPLIFYING SOUTHERN STREAM WAVE. SFC HIGH
PRESSURE OVER THE MID-ATLANTIC IS PROGGED TO STRENGTHEN AND SHIFT
NORTHEAST INTO NEW ENGLAND ON SUNDAY...WITH A PROMINENT SFC RIDGE
AXIS EXTENDING SOUTH INTO THE CAROLINAS. ALTHOUGH UPPER LEVEL LIFT
WILL BE RATHER ANEMIC SUNDAY...ISENTROPIC LIFT IN THE LOWER LEVELS
WILL BE STRENGTHENING FROM THE SOUTH/SW THROUGHOUT THE DAY AS THE
925-850MB WARM FRONT STALLS OUT JUST TO THE SOUTH IN SC AND THE
MSLP/HEIGHT GRADIENT TIGHTENS BETWEEN THE SFC RIDGE EXTENDING SOUTH
INTO THE AREA AND WEAK LOW PRESSURE OVER THE DEEP SOUTH AND
CAROLINA/SOUTHEAST COAST. BASED ON THE 12Z MODEL RUNS...THE TIMING
OF THE ARRIVAL OF PRECIP IS QUITE DELAYED COMPARED TO PREVIOUS
RUNS...WITH THE BEST CHANCE FOR RAIN STARTING IN THE SOUTH/SW IN THE
AFTERNOON...SPREADING NORTHWARD INTO THE TRIANGLE AREA BY OR SHORTLY
AFTER SUNSET. WILL SHOW HIGHEST POPS (CATEGORICAL/LIKELY) IN THE SW
PIEDMONT AND SANDHILLS...TAPERING DOWN TO SLIGHT CHANCE N/NE OF THE
TRIANGLE. RAINFALL AMOUNTS SHOULD BE NO HIGHER THAN 0.10-0.25" IN
THE SW PIEDMONT/SANDHILLS. TEMPERATURE FCST SOMEWHAT DIFFICULT ON
SUN...DEPENDING PRIMARILY ON THE ARRIVAL OF PRECIP. LATEST MOS
GUIDANCE HAS COME IN WARMER IN ALMOST ALL LOCATIONS...RANGING FROM
THE MID/UPPER 50S TO THE LOWER 60S...AND THAT LOOKS PRETTY
REASONABLE BASED ON THE DELAYED ONSET OF PRECIP. -VINCENT
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 135 PM SATURDAY...
FOR SUNDAY NIGHT/MONDAY: THE PARENT SURFACE HIGH STRENGTHENS FURTHER
TO AROUND 1033 MB AND DRIFTS FROM OVER MAINE ACROSS THE CANADIAN
MARITIMES THROUGH MONDAY. THE INVERTED SURFACE TROUGH JUST WEST OF
THE SOUTHERN APPALACHIANS WEAKENS GRADUALLY WHILE THE SECONDARY
SURFACE CYCLOGENESIS BEGINS OFF THE SC COAST WITH ITS CENTER THEN
PASSING NEAR THE OUTER BANKS THROUGH MONDAY. THE SUBCLOUD LAYER OVER
CENTRAL NC FINALLY BEGINS TO SATURATE FROM SOUTHWEST TO NORTHEAST
SUNDAY EVENING WITH INCREASING MOIST ISENTROPIC UPGLIDE AT 290K-300K
AND INCREASING LOW LEVEL MASS CONVERGENCE AND MOISTURE TRANSPORT.
HOWEVER... DEEP FORCING FOR ASCENT REMAINS SOMEWHAT LIMITED. THE
DPVA DECREASES RAPIDLY LATE SUNDAY THROUGH SUNDAY NIGHT AS THE
DAMPENING MID LEVEL SHORTWAVE TROUGH SWINGS UP THROUGH EASTERN TN
AND WESTERN NC... AND UPPER DIVERGENCE (WHILE MAXIMIZED OVER NC AT
06Z SUNDAY NIGHT) TRENDS WEAKER AS WELL. AND BY THE TIME THE LOWEST
1-2 KM BECOMES SATURATED... WE LOSE THE MOISTURE ALOFT AS THE VERY
DRY AIR NOW OVER NM/WEST TX/OK PUNCHES IN ON THE BACK SIDE OF THE
SHORTWAVE TROUGH. THESE FACTORS SHOULD RESULT IN RATHER LOW QPF...
ALTHOUGH GIVEN THAT THE LOW LEVEL FORCING FEATURES LINE UP WELL...
WE STILL ANTICIPATE WIDESPREAD LIGHT RAIN AND DRIZZLE FROM SUNDAY
NIGHT THROUGH MONDAY... AND WILL RETAIN CATEGORICAL POPS... MAINLY
FROM LATE EVENING SUNDAY THROUGH MONDAY MORNING BEFORE TAPERING OFF
POPS TO A CHANCE OF LIGHT RAIN/DRIZZLE NORTH TO SOUTH THROUGH MONDAY
AFTERNOON. LOWS 46-51. THEN WITH THICK OVERCAST PERSISTING THROUGH
MONDAY... LOW LEVEL COLD AIR ADVECTION... AND THE COASTAL LOW
HOLDING OFFSHORE... TEMPS SHOULD RISE VERY LITTLE MONDAY. HIGHS
49-59... AND EVEN THIS MAY BE OPTIMISTIC WITHIN THE HEART OF THE
COLD DOME IN THE NORTHERN PIEDMONT.
FOR MONDAY NIGHT/TUESDAY: THE COASTAL LOW IS EXPECTED TO TRACK
SLOWLY FROM THE NORTHERN OUTER BANKS TO OFF THE NJ COAST BY LATE
TUESDAY. THE PARENT HIGH CONTINUES TO SHIFT EAST OFF THE CANADIAN
MARITIMES AND LOSES ITS GRIP ON THE WEDGE AIR MASS OVER CENTRAL
NC... HOWEVER IT LEAVES BEHIND A FORMIDABLE COOL POOL. FORECAST
SOUNDINGS FROM BOTH THE NAM AND GFS SHOW STABLE AIR AND PLENTY OF
MOISTURE IN THE LOWEST 2 KM THROUGH MONDAY NIGHT... AND THE GFS
HOLDS ONTO LOW LEVEL ISENTROPIC UPGLIDE IN THIS LAYER AROUND 295K. A
WEAK SHORTWAVE PASSES BY MONDAY NIGHT BUT WITH NO MOISTURE ALOFT AND
STABLE/WARMING MID LEVELS... IT SHOULD HAVE NO SENSIBLE IMPACT IN
THIS AREA. WITH WEAK AND LIGHTLY DIFFLUENT MAINLY NORTHERLY SURFACE
WINDS THROUGH THE NIGHT AND SATURATED LOW LEVELS... WE SHOULD SEE
AREAS OF LIGHT DRIZZLE AND FOG THROUGH TUESDAY MORNING. HAVE BROUGHT
LOWS UP SLIGHTLY TO 45-49. ON TUESDAY... THE GFS KEEPS THE LOW
LEVELS NEARLY ISOTHERMAL AND SATURATED WHEREAS THE NAM WANTS TO
START DRYING THIS LAYER OUT. THE MODELS OFTEN HAVE DIFFICULTING
CORRECTLY DEPICTING EROSION OF A DAMMING AIR MASS THAT HAS LOST
LARGE SCALE SUPPORT AND NO LONGER HAS ANY CONNECTION TO A COOL DRY
LOW LEVEL AIR SOURCE. DESPITE HEATING FROM ABOVE WHICH MAY START TO
BURN OFF THE UPPER PORTION OF THIS MOIST LAYER... GIVEN THE DRY
SUBSIDENCE LAYER ALOFT CAPPING OFF THIS SURFACE-BASED LAYER AND WITH
WEAK WINDS IN THE LOWEST 1 KM INHIBITING MIXING... FAVOR A LEAN
TOWARD THE GFS (WHICH HAS SUPPORT FROM THE CANADIAN) WHICH MEANS
HOLDING ONTO CONSIDERABLE CLOUDINESS THROUGH TUESDAY. WITH THIS
GREATER CLOUD COVER... HIGHS WILL ACCORDINGLY BE LOWERED... TO
58-65. -GIH
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 240 PM FRIDAY...
FOR TUESDAY NIGHT: THE GFS/CANADIAN DEPICT A WEAK 850 MB WARM FRONT
SWINGING NORTHEASTWARD LEADING TO LOW LEVEL WINDS BECOMING MORE
UNIFORM (YET STILL LIGHT) FROM THE WEST-SOUTHWEST BY MORNING. GFS
FORECAST SOUNDINGS SHOW A DISSOLUTION OF THE LOW CLOUDS ESPECIALLY
IN THE WESTERN AND SOUTHERN CWA. WILL SHOW A TREND TOWARD FEWER
CLOUDS IN THIS AREA OVERNIGHT BUT BASED ON UNCERTAINTY WITH SUCH A
FEATURE THIS FAR OUT... WILL NOT COMPLETELY CLEAR OUT THE CLOUDS.
LOWS 43-48.
FOR WEDNESDAY THROUGH SATURDAY: MODEL CONSENSUS SHOWS DEEP TROUGHING
DOMINATING THE EASTERN HALF OF THE NATION THROUGH AT LEAST FRIDAY...
WITH THE SURFACE BAROCLINIC ZONE HOLDING OFF THE SOUTHEAST COAST.
THE GFS/ECMWF/CANADIAN AGREE FAIRLY WELL ON ONE MID LEVEL VORTEX
OVER THE MIDWEST EARLY WEDNESDAY SWINGING EAST THEN NORTH THROUGH
QUEBEC THROUGH FRIDAY... WHILE ANOTHER VORTEX DROPS FROM NEAR LAKE
WINNEPEG THROUGH THE MIDWEST TO THE EASTERN GREAT LAKES REGION AND
FINALLY TRACKS UP ALONG THE ST LAWRENCE VALLEY INTO SATURDAY. THIS
CERTAINLY LOOKS TO BE AN ANOMALOUSLY DEEP PATTERN AS THE GEFS MEAN
MID LEVEL HEIGHTS DROP TO 1-3 STANDARD DEVIATIONS BELOW NORMAL BY
FRIDAY OVER THE SOUTHEAST. SURFACE DETAILS ARE TOUGH TO PINPOINT
WITHIN SUCH A FAST FLOW ALOFT BUT IT APPEARS THAT WE`LL SEE A
LARGELY DRY COLD FRONT PASSING THROUGH WEDNESDAY NIGHT OR EARLY
THANKSGIVING DAY... FOLLOWED BY FALLING LOW LEVEL THICKNESSES AND
DRY BUT BRISK NORTHWESTERLY LOW LEVEL FLOW AS A POLAR-SOURCE HIGH
PRESSURE RIDGE BUILDS IN SLOWLY FROM THE WEST-SOUTHWEST. WILL KEEP A
SLIGHT CHANCE OF RAIN MAINLY ACROSS THE NORTH WEDNESDAY NIGHT INTO
THANKSGIVING DAY... THEN INDICATE DRY AND COLDER WEATHER FOR
THURSDAY NIGHT THROUGH SATURDAY. EXPECT ABOVE-NORMAL TEMPS
WEDNESDAY... SLIGHTLY COOLER (NEAR NORMAL) THANKSGIVING DAY... THEN
THE BULK OF THE COLD AIR ARRIVES THURSDAY NIGHT WITH LOW LEVEL
THICKNESSES PLUNGING BELOW 1310 M ON THE GFS AND CANADIAN BY FRIDAY
MORNING. WILL HOLD TEMPS ABOUT ONE TO TWO CATEGORIES BELOW NORMAL
FRIDAY THROUGH SATURDAY... WITH HIGHS IN THE LOWER-MID 50S. -GIH
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1245 PM SATURDAY...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. UPPER LEVEL
CLOUD COVER WILL CONTINUE TO INCREASE OVER THE AREA IN ADVANCE OF A
STORM SYSTEM CURRENTLY LOCATED ALONG THE NORTHWEST GULF COAST.
CEILINGS ARE EXPECTED TO REMAIN IN THE 15-18 KFT RANGE THROUGH
TONIGHT. CEILINGS WILL BEGIN TO LOWER DURING THE DAY SUNDAY...
HOWEVER...ANY MVFR/IFR CEILINGS AND RAIN ARE EXPECTED TO HOLD OFF
UNTIL AFTER THE END OF THE CURRENT TAF PERIOD.
MVFR/IFR CONDITIONS IN RAIN ARE EXPECTED TO AFFECT MOST OR ALL OF
THE AREA FROM 00Z MON THROUGH 00Z TUE...WITH MVFR/IFR AND PERHAPS
LIFR CONDITIONS IN LOW CEILINGS/FOG/DRIZZLE MONDAY NIGHT THROUGH
TUESDAY NIGHT IN ASSOC/W A SATURATED WEDGE OF COOL AIR (CAD WEDGE)
IN THE LOWEST SEVERAL THOUSAND FEET OF THE ATMOSPHERE.
VFR CONDITIONS SHOULD RETURN BY MID-WEEK (WED) IN ASSOC/W A FRONTAL
PASSAGE. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...VINCENT
000
FXUS62 KMHX 211921
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
221 PM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...THEN SLIDE
OFFSHORE TONIGHT. LOW PRESSURE WILL DEVELOP JUST OFFSHORE LATE
SUNDAY AND SUNDAY NIGHT...THEN LIFT NE ON MONDAY. HIGH PRESSURE
WILL REBUILD OVER THE AREA TUESDAY AND WEDNESDAY. A COLD FRONT
WILL APPROACH FROM THE WEST ON THURSDAY AND MOVE OFFSHORE
FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DESPITE THE COOL NE FLOW REGIME...PARTIAL SUNSHINE AND WEAK
THICKNESS RIDGING ALOFT WILL ALLOW TEMPS TO RISE ANTHR 5-10 DEGS
THIS AFTN. NAM FCST SOUNDING CONT TO SHOW A NEARLY SATURATED LYR
NEAR 5000 FT THIS AFTN SO EXPECT WILL SEE DECENT AMOUNT OF STRATO-
CU...WILL ALSO HAVE SOME HIGH CLOUDS TODAY BUT EXPECT ENUF PEAKS
OF SUN TO GET HIGHS IN THE 60 TO 65 DGR RANGE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS OF 2 AM SAT...CLOUDS WILL THICKEN TONIGHT AS BEGIN TO SEE LOW
LVL MOISTURE INCREASE PLUS WILL HAVE SOME MID/HIGH CLOUDS WELL
AHEAD OF APPROACHING SRT WAVE. CONT PREV FCST OF SLIGHT POP LATE
TONIGHT SRN TIER. LOWS MAINLY UPR 40S TO LOWER 50S. RAIN WILL BE
INCREASING FROM SW TO NE SUNDAY AS INSENT LIFT INCREASES OVER THE
AREA AS CSTL FRONT TAKES SHAPE JUST OFFSHORE AHEAD OF APPROACHING
SRT WAVE. CONT LIKELY POPS INLAND TO CHC NE CST LATER SUNDAY. SUN
NIGHT LOOKS WET AS ISENT LIFT CONTS WITH INCREASING MID/UPR
SUPPORT WITH SRT WAVE PASSING BY TO THE NW. HAVE CATEGORICAL POPS
ALL AREAS SUN NIGHT. RAIN WILL GRAD DIMINISH FROM SW TO NE MON
HOWEVER WILL STILL HAVE GOOD CVRG EARLY AND CONT CATEGORICAL NE
CST TO LIKELY POPS ELSEWHERE WITH POPS DECREASING TO CHC LATE.
TOTAL QPF FROM THIS EVENT LOOKS TO AVG OUT IN 0.5 TO 1 INCH RANGE AND
DESPITE VERY WET GROUND MANY AREAS SHLD NOT CAUSE SIGNIFICANT
PROBLEMS. HIGHS BOTH SUN AND MON WITH CLOUDS...PRECIP AND NE WINDS
WILL BE MAINLY IN THE UPPER 50S TO LOWER 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 2 AM SAT...ANY LINGERING LIGHT RAIN/DRIZZLE WILL END MON
NIGHT. WITH HIGH PRES BUILDING IN TUE AND WED EXPECT DRY
CONDITIONS. IMPRESSIVE SRT WAVE/COLD FRONT WILL APPROACH THU AND
MOVE OFFSHORE FRI. MDLS DIFFER WITH GFS SHOWING LIMITED MOISTURE
AND BULK OF PRECIP OFFSHORE. EMCWF IS WETTER...ESPCLY CST WITH
MOISTURE COMING IN OFF ATLC. CURRENTLY HAVE CHC POPS THU AND WILL
NOT CHANGE UNTIL GET MORE CLARITY FROM MDLS. COOLER AND DRY FRI IN
WAKE OF FRONT/SRT WAVE.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
AS OF 2 PM SAT...GFS LAMP AND NAM GUIDANCE CONTINUES TO SLOW DOWN
THE PROGRESSION OF THE MOISTURE INTO THE REGION...AND GENERAL LACK
OF SUPPORT FOR MUCH CLOUD DEVELOPMENT. HAVE GONE A BIT FASTER
BRINGING IN THE MID DECK OVERNIGHT WITH CLOUDS DROPPING INTO SUN
AS THE RAIN ADVANCES ON THE REGION. THE RAIN WILL MOVE IN LATE SUN
INTO MON...WITH LOW CLOUDS EXP TO LINGER POTENTIALLY INTO TUE.
HIGH PRES WILL BUILD OVER THE REGION THEREAFTER...WITH CLEARING
AND PREDOMINANT VFR CONDITIONS. HOWEVER HIGHER TD COULD LEAD TO
OVERNIGHT FOG OR STRATUS DEVELOPMENT TUE NT AND WED NT.
&&
.MARINE...
AS OF 2 PM SAT...THE WEAK LOW OFFSHORE AND HIGH PRES TO OUR N
IS PRODUCING WINDS 20-25KT WINDS MAINLY S OF OREGON INLET. SEAS
HAVE BOUNCED AROUND 5 TO 8 FT THIS AFT...WITH CONDITIONS EXP TO
CHANGE LITTLE THIS EVENING. LATER TNT AS THE LOW MOVES E WE WILL
SEE AN IMPROVEMENT IN WINDS...THOUGH SEAS WILL REMAIN UP ESP
SOUTH. MEANWHILE...SATELLITE SHOWS A CLEARLY DEFINED LOW OVER THE
GULF STATES WHICH WILL MOVE E SUN AND OVER THE CAROLINAS BY MON.
THE LOW IS EXP TO REMAIN POORLY ORGANIZED AS UPPER LVL SUPPORT
WEAKENS. THE TRACK OF THIS WEAK SYSTEM WILL MOVE NEAR OR OVER
HATTERAS...WHICH WILL KEEP THE LIGHTEST WINDS OVER THIS REGION.
HOWEVER THE SE WINDS AHEAD AND BEHIND THE LOW COULD BRIEFLY GUST
TO SMALL CRAFT. THE N WATERS WILL LIKELY REMAIN AROUND 20KT AS THE
LOW PASSES TO THE S. THE SEAS WILL REMAIN ABV SCA THROUGH OUT MON
NT.
BY MON THE STRONG HIGH OVER NEW ENGLAND WILL SLIDE E OFFSHORE.
MEANWHILE AN AREA OF LOW PRES NEAR 50W WILL PINCH THE GRAD AND
COMBINED WITH SOME HIGHER SEAS OVER THE N ATLANTIC WILL PRODUCE
SOME DOUBLE DIGIT SEAS. THE ENE FETCH AROUND THE HIGH WILL STEER A
LOT OF THIS ENERGY TOWARDS THE E COAST...AND THOUGH IT WILL
DIMINISH GREATLY BEFORE IT REACHES THE COAST IT COULD ADD SOME
SWELL TO THE SEA HEIGHTS TO THE LOCAL WATERS EARLY TO MID WEEK.
THE HIGH PRES SLIDING OVER THE REGION WILL AID IN DROPPING WIND
SPEEDS SO COMBINED SEAS COULD DROP BELOW 6FT DURING THIS
TIME...HOWEVER N WATERS COULD REMAIN UP THROUGH THE REST OF THE
FCST IF WAVEWATCH SEAS WERE ACCURATE. DUE TO LIMITED OBSERVATIONS
OVER THAT PART OF THE ATLANTIC CAN`T VERIFY THE INITIAL CONDITIONS
OF WAVEWATCH...SO HAVE SHAVED ABOUT A FOOT OFF THE OUTPUT BY
TUE/WED UNTIL THERE IS MORE SUPPORT OF THIS LONG PERIOD SWELL. A
CLOSED UPPER LOW DIGGING OUT OF THE GREAT LAKES REGION COULD LEAD
TO CYCLOGENESIS OFF THE MID ATLANTIC COAST BY THU. MOST MODELS
SUPPORT A WEAK LOW PASSING OBX AND STRENGTHENING AT IS MOVES
TOWARDS NEW ENGLAND...WITH THE CANADIAN BEING THE STRONGEST
SOLUTIONS OF A COASTAL LOW SKIRTING NC. WITH THE UPPER SUPPORT
BEING MUCH FURTHER N THAN OUR LAST COASTAL LOW...FEEL THE WEAKER
SOLUTIONS HERE ARE MORE LIKELY. HOWEVER...THE CAA ON THE BACKSIDE
OF THE LOW THU NT INTO FRI WILL INCREASE TO SCA IN STRONG NW
WINDS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...RF
NEAR TERM...BTC/RF
SHORT TERM...RF
LONG TERM...RF
AVIATION...SJ
MARINE...SJ
000
FXUS62 KRAH 211839
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
135 PM EST SAT NOV 21 2009
.SYNOPSIS...
A LOW PRESSURE SYSTEM IN THE NORTHWEST GULF OF MEXICO WILL MOVE
SLOWLY NORTHEAST TOWARD THE FLORIDA GULF COAST TONIGHT...BEFORE
WEAKENING AND REFORMING ALONG THE CAROLINA COAST SUNDAY NIGHT. THIS
WILL BRING INCREASING CLOUD COVER AND A GOOD CHANCE OF RAIN TO
CENTRAL NORTH CAROLINA BY SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 1200 PM SATURDAY...
16Z SFC ANALYSIS SHOWED 1024 MB HIGH PRESSURE CENTERED OVER OH/WV.
1010 MB LOW PRESSURE WAS CENTERED NEAR BUOY 42361 SOUTH OF LA.
ALOFT...12Z RAOB ANALYSIS SHOWED A SPLIT FLOW PATTERN ACROSS THE
CONUS. A SOUTHERN STREAM 500 MB LOW WAS CENTERED OVER SOUTHEAST TX.
A 90 KT SOUTHERN STREAM JET WAS NOTED ALONG THE SOUTHERN PERIPHERY
OF THE UPPER LOW OVER NORTHERN MEXICO AND THE NORTHERN GOMEX. A 100
KT NORTHERN STREAM JET WAS NOTED OVER THE NORTHERN MID-ATLANTIC
AHEAD OF A DEAMPLIFYING NORTHERN STREAM TROUGH OVER THE LOWER GREAT
LAKES. A RIDGE ALOFT WAS PRESENT OVER THE CENTRAL AND NORTHERN GREAT
PLAINS.
TODAY:
THE UPPER LOW CURRENTLY OVER SOUTHEAST TX IS PROGGED TO MOVE ENE
INTO LA BY 00Z THIS EVENING...WHILE THE ASSOC SFC LOW CURRENTLY OVER
THE NORTHWEST GOMEX IS PROGGED TO BE LOCATED JUST SOUTH OF THE LA
COAST BY THAT TIME. SFC HIGH PRESSURE IS EXPECTED TO REMAIN CENTERED
OVER PORTIONS OF THE MID-ATLANTIC...LOWER GREAT LAKES AND OH VALLEY
IN ASSOC/W CONFLUENT FLOW ALOFT...WITH A SFC RIDGE AXIS EXTENDING
SOUTH INTO THE CAROLINAS. EXPECT A STEADY INFLUX OF MID/UPPER LEVEL
CLOUD COVER THROUGHOUT THE DAY TODAY AS MOISTURE MOVES DOWNSTREAM OF
THE UPPER LOW ALONG THE GULF COAST INTO THE SOUTHEAST STATES AND
CAROLINAS. MOISTURE ADVECTION WILL GENERALLY BE LIMITED TO THE UPPER
LEVELS TODAY...AND CLOUD BASES WILL REMAIN AOA 15-18 KFT. LIFT TODAY
WILL BE EITHER VERY WEAK OR NON-EXISTENT ACROSS CENTRAL NC. ALTHOUGH
THERE IS CURRENTLY A NORTHERN STREAM JET ENTRANCE REGION N/NW OF
CENTRAL NC...THIS FEATURE IS PROGGED TO WEAKEN AND LIFT NORTHEAST
AWAY FROM THE AREA. MODEL ISENTROPIC FIELDS DO INDICATE INCREASING
ISENTROPIC LIFT ACROSS THE SOUTHEAST STATES THIS AFT/EVE AS A
925-850 MB WARM FRONT MOVES NORTHWARD TOWARD THE CENTRAL GULF COAST
AHEAD OF THE SFC/UPPER LOW IN LA. HOWEVER...ISENTROPIC LIFT WILL BE
WEAK AND CONFINED WELL SOUTH/SW OF CENTRAL NC. AS A RESULT...EXPECT
NO CHANCE FOR PRECIP THIS AFT/EVE. HIGH TEMPS WILL BE COMPLICATED
PRIMARILY BY BROKEN SKIES ASSOC/W UPPER LEVEL CLOUD COVER.
THICKNESSES WOULD ARGUE FOR HIGHS IN THE ~63F RANGE WITH FULL SUN...
HOWEVER...GIVEN WEAK LOW LEVEL NORTHEAST FLOW AND BROKEN UPPER LEVEL
CLOUD COVER...A RANGE OF 60-63F LOOKS MORE REASONABLE...ALTHOUGH
EVEN THAT COULD BE WARM BY 1-2F DEPENDING ON THE OPACITY OF CLOUD
COVER.
TONIGHT:
THE UPPER LOW CURRENTLY OVER SOUTHEAST TX IS PROGGED TO DEAMPLIFY
TONIGHT AS IT MOVES SLOWLY ENE INTO THE DEEP SOUTH. THE ATTENDANT
SFC LOW IS ALSO PROGGED TO WEAKEN A FEW MILLIBARS AS IT MOVES ALONG
A BAROCLINIC ZONE LOCATED OVER THE CENTRAL/NORTHEAST GULF COAST.
DESPITE THE WEAKENING SOUTHERN STREAM DYNAMICS...ISENTROPIC LIFT IS
EXPECTED TO STRENGTHEN OVER THE SOUTHEAST STATES INTO THE SOUTHERN
CAROLINAS TONIGHT AS A 925-850 MB WARM FRONT LIFTS NORTHWARD INTO
AL/GA AHEAD OF THE LOW PRESSURE SYSTEM ALONG THE GULF COAST. THE
BEST LOW LEVEL MOISTURE AND ISENTROPIC LIFT IS EXPECTED TO REMAIN
WELL S/SW OF CENTRAL NC THROUGH 12Z SUN...WITH PRECIP CHANCES
LARGELY CONFINED TO AL/GA AND PERHAPS SOUTHERN/WESTERN PORTIONS OF
SC. AS A RESULT...EXPECT A DRY FORECAST TO CONTINUE THROUGH THE
OVERNIGHT HOURS. MID/UPPER LEVEL CLOUD COVER WILL BE PERVASIVE
ACROSS THE AREA TONIGHT IN ASSOC/W THE LOW PRESSURE SYSTEM UPSTREAM
OF THE AREA...AND THAT WILL BE THE PRIMARY COMPLICATING FACTOR
W/REGARD TO LOW TEMPS. A MOS GUIDANCE BLEND LOOKS PRETTY
REASONABLE...WITH LOWS IN THE LOWER/MID 40S.
SUNDAY:
LATEST 12Z MODEL GUIDANCE CONTINUES TO SHOW THE 500 MB LOW
DEAMPLIFYING INTO A SHORTWAVE DURING THE DAY SUNDAY AS IT MOVES N/NE
INTO NORTHERN AL/GA AND EASTERN TN. THE ATTENDANT GULF COAST SFC LOW
IS PROGGED TO WEAKEN AS IT REMAINS CENTERED NEAR THE FL/AL COAST. AN
INVERTED SFC TROUGH/COASTAL FRONT IS EXPECTED TO SHARPEN OFF THE
SOUTHEAST/CAROLINA COAST DURING THE DAY SUN IN ASSOC/W WEAK UPPER
FORCING ASSOC/W THE DEAMPLIFYING SOUTHERN STREAM WAVE. SFC HIGH
PRESSURE OVER THE MID-ATLANTIC IS PROGGED TO STRENGTHEN AND SHIFT
NORTHEAST INTO NEW ENGLAND ON SUNDAY...WITH A PROMINENT SFC RIDGE
AXIS EXTENDING SOUTH INTO THE CAROLINAS. ALTHOUGH UPPER LEVEL LIFT
WILL BE RATHER ANEMIC SUNDAY...ISENTROPIC LIFT IN THE LOWER LEVELS
WILL BE STRENGTHENING FROM THE SOUTH/SW THROUGHOUT THE DAY AS THE
925-850MB WARM FRONT STALLS OUT JUST TO THE SOUTH IN SC AND THE
MSLP/HEIGHT GRADIENT TIGHTENS BETWEEN THE SFC RIDGE EXTENDING SOUTH
INTO THE AREA AND WEAK LOW PRESSURE OVER THE DEEP SOUTH AND
CAROLINA/SOUTHEAST COAST. BASED ON THE 12Z MODEL RUNS...THE TIMING
OF THE ARRIVAL OF PRECIP IS QUITE DELAYED COMPARED TO PREVIOUS
RUNS...WITH THE BEST CHANCE FOR RAIN STARTING IN THE SOUTH/SW IN THE
AFTERNOON...SPREADING NORTHWARD INTO THE TRIANGLE AREA BY OR SHORTLY
AFTER SUNSET. WILL SHOW HIGHEST POPS (CATEGORICAL/LIKELY) IN THE SW
PIEDMONT AND SANDHILLS...TAPERING DOWN TO SLIGHT CHANCE N/NE OF THE
TRIANGLE. RAINFALL AMOUNTS SHOULD BE NO HIGHER THAN 0.10-0.25" IN
THE SW PIEDMONT/SANDHILLS. TEMPERATURE FCST SOMEWHAT DIFFICULT ON
SUN...DEPENDING PRIMARILY ON THE ARRIVAL OF PRECIP. LATEST MOS
GUIDANCE HAS COME IN WARMER IN ALMOST ALL LOCATIONS...RANGING FROM
THE MID/UPPER 50S TO THE LOWER 60S...AND THAT LOOKS PRETTY
REASONABLE BASED ON THE DELAYED ONSET OF PRECIP. -VINCENT
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 135 PM SATURDAY...
FOR SUNDAY NIGHT/MONDAY: THE PARENT SURFACE HIGH STRENGTHENS FURTHER
TO AROUND 1033 MB AND DRIFTS FROM OVER MAINE ACROSS THE CANADIAN
MARITIMES THROUGH MONDAY. THE INVERTED SURFACE TROUGH JUST WEST OF
THE SOUTHERN APPALACHIANS WEAKENS GRADUALLY WHILE THE SECONDARY
SURFACE CYCLOGENESIS BEGINS OFF THE SC COAST WITH ITS CENTER THEN
PASSING NEAR THE OUTER BANKS THROUGH MONDAY. THE SUBCLOUD LAYER OVER
CENTRAL NC FINALLY BEGINS TO SATURATE FROM SOUTHWEST TO NORTHEAST
SUNDAY EVENING WITH INCREASING MOIST ISENTROPIC UPGLIDE AT 290K-300K
AND INCREASING LOW LEVEL MASS CONVERGENCE AND MOISTURE TRANSPORT.
HOWEVER... DEEP FORCING FOR ASCENT REMAINS SOMEWHAT LIMITED. THE
DPVA DECREASES RAPIDLY LATE SUNDAY THROUGH SUNDAY NIGHT AS THE
DAMPENING MID LEVEL SHORTWAVE TROUGH SWINGS UP THROUGH EASTERN TN
AND WESTERN NC... AND UPPER DIVERGENCE (WHILE MAXIMIZED OVER NC AT
06Z SUNDAY NIGHT) TRENDS WEAKER AS WELL. AND BY THE TIME THE LOWEST
1-2 KM BECOMES SATURATED... WE LOSE THE MOISTURE ALOFT AS THE VERY
DRY AIR NOW OVER NM/WEST TX/OK PUNCHES IN ON THE BACK SIDE OF THE
SHORTWAVE TROUGH. THESE FACTORS SHOULD RESULT IN RATHER LOW QPF...
ALTHOUGH GIVEN THAT THE LOW LEVEL FORCING FEATURES LINE UP WELL...
WE STILL ANTICIPATE WIDESPREAD LIGHT RAIN AND DRIZZLE FROM SUNDAY
NIGHT THROUGH MONDAY... AND WILL RETAIN CATEGORICAL POPS... MAINLY
FROM LATE EVENING SUNDAY THROUGH MONDAY MORNING BEFORE TAPERING OFF
POPS TO A CHANCE OF LIGHT RAIN/DRIZZLE NORTH TO SOUTH THROUGH MONDAY
AFTERNOON. LOWS 46-51. THEN WITH THICK OVERCAST PERSISTING THROUGH
MONDAY... LOW LEVEL COLD AIR ADVECTION... AND THE COASTAL LOW
HOLDING OFFSHORE... TEMPS SHOULD RISE VERY LITTLE MONDAY. HIGHS
49-59... AND EVEN THIS MAY BE OPTIMISTIC WITHIN THE HEART OF THE
COLD DOME IN THE NORTHERN PIEDMONT.
FOR MONDAY NIGHT/TUESDAY: THE COASTAL LOW IS EXPECTED TO TRACK
SLOWLY FROM THE NORTHERN OUTER BANKS TO OFF THE NJ COAST BY LATE
TUESDAY. THE PARENT HIGH CONTINUES TO SHIFT EAST OFF THE CANADIAN
MARITIMES AND LOSES ITS GRIP ON THE WEDGE AIR MASS OVER CENTRAL
NC... HOWEVER IT LEAVES BEHIND A FORMIDABLE COOL POOL. FORECAST
SOUNDINGS FROM BOTH THE NAM AND GFS SHOW STABLE AIR AND PLENTY OF
MOISTURE IN THE LOWEST 2 KM THROUGH MONDAY NIGHT... AND THE GFS
HOLDS ONTO LOW LEVEL ISENTROPIC UPGLIDE IN THIS LAYER AROUND 295K. A
WEAK SHORTWAVE PASSES BY MONDAY NIGHT BUT WITH NO MOISTURE ALOFT AND
STABLE/WARMING MID LEVELS... IT SHOULD HAVE NO SENSIBLE IMPACT IN
THIS AREA. WITH WEAK AND LIGHTLY DIFFLUENT MAINLY NORTHERLY SURFACE
WINDS THROUGH THE NIGHT AND SATURATED LOW LEVELS... WE SHOULD SEE
AREAS OF LIGHT DRIZZLE AND FOG THROUGH TUESDAY MORNING. HAVE BROUGHT
LOWS UP SLIGHTLY TO 45-49. ON TUESDAY... THE GFS KEEPS THE LOW
LEVELS NEARLY ISOTHERMAL AND SATURATED WHEREAS THE NAM WANTS TO
START DRYING THIS LAYER OUT. THE MODELS OFTEN HAVE DIFFICULTING
CORRECTLY DEPICTING EROSION OF A DAMMING AIR MASS THAT HAS LOST
LARGE SCALE SUPPORT AND NO LONGER HAS ANY CONNECTION TO A COOL DRY
LOW LEVEL AIR SOURCE. DESPITE HEATING FROM ABOVE WHICH MAY START TO
BURN OFF THE UPPER PORTION OF THIS MOIST LAYER... GIVEN THE DRY
SUBSIDENCE LAYER ALOFT CAPPING OFF THIS SURFACE-BASED LAYER AND WITH
WEAK WINDS IN THE LOWEST 1 KM INHIBITING MIXING... FAVOR A LEAN
TOWARD THE GFS (WHICH HAS SUPPORT FROM THE CANADIAN) WHICH MEANS
HOLDING ONTO CONSIDERABLE CLOUDINESS THROUGH TUESDAY. WITH THIS
GREATER CLOUD COVER... HIGHS WILL ACCORDINGLY BE LOWERED... TO
58-65. -GIH
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 315 AM FRIDAY...
THE FORECAST GETS QUITE A BIT MORE COMPLICATED BEYOND TUESDAY...WITH
THE HANDLING OF A SHORTWAVE EXPECTED TO ENTER THE PACIFIC NORTHWEST
ON MONDAY AND EMERGE OVER THE NORTH CENTRAL PLAINS BY WED. THE
GENERAL TREND IS FOR THE DEVELOPMENT OF A HIGH AMPLITUDE LONGWAVE
TROUGH BY THE END OF THE WEEK...AND WHILE BOTH THE GFS AND ECMWF
RESOLVE SUCH A SOLUTION...THEY CURRENTLY GET THE SIMILAR ANSWER
THROUGH SOMEWHAT DIFFERENT SCENARIOS. THE GFS SENDS THE
AFOREMENTIONED SHORTWAVE ACROSS THE UPPER MIDWEST AND THE LIFTS THE
SYSTEM INTO ONTARIO BY THURSDAY...PUSHING A DRY COLD FRONT INTO
CENTRAL NC WED NIGHT. THIS IS FOLLOWED BY A SECOND SHORTWAVE THAT
DIVES SOUTH THROUGH THE MIDWEST...BUT WITH NO MORE TO WORK
WITH....POINTS EAST OF THE MOUNTAINS STAY DRY EVEN AS A SURFACE WAVE
IS INDUCED OFFSHORE THURSDAY MORNING. THE ECMWF ON THE OTHER HAND
IS MUCH SLOWER WITH THE FIRST SHORTWAVE...ALLOWING MORE MOISTURE TO
BE PULLED NORTH OVER A PERSISTENT SURFACE RIDGE ALONG THE EASTERN
SEABOARD. CYCLOGENESIS ALONG THE COAST SUBSEQUENTLY OCCURS CLOSER
TO THE COAST THURSDAY MORNING WITH LESS EASTWARD PROGRESSION OF THE
SURFACE FRONT...AND THUS THE ECMWF PRODUCES PRECIP OVER THE EASTERN
THIRD OF NC. GIVEN THESE CONTINUED MODEL INCONSISTENCIES...FEEL THE
BEST COURSE OF ACTION IS TO SHOW BELOW NORMAL TEMPS FOR THE END OF
THE WEEK...CONTINUING WITH HIGHER SLIGHT CHANCE POPS IN THE EAST
UNTIL SOME SORT OF MODEL CONVERGENCE BEGINS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1245 PM SATURDAY...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. UPPER LEVEL
CLOUD COVER WILL CONTINUE TO INCREASE OVER THE AREA IN ADVANCE OF A
STORM SYSTEM CURRENTLY LOCATED ALONG THE NORTHWEST GULF COAST.
CEILINGS ARE EXPECTED TO REMAIN IN THE 15-18 KFT RANGE THROUGH
TONIGHT. CEILINGS WILL BEGIN TO LOWER DURING THE DAY SUNDAY...
HOWEVER...ANY MVFR/IFR CEILINGS AND RAIN ARE EXPECTED TO HOLD OFF
UNTIL AFTER THE END OF THE CURRENT TAF PERIOD.
MVFR/IFR CONDITIONS IN RAIN ARE EXPECTED TO AFFECT MOST OR ALL OF
THE AREA FROM 00Z MON THROUGH 00Z TUE...WITH MVFR/IFR AND PERHAPS
LIFR CONDITIONS IN LOW CEILINGS/FOG/DRIZZLE MONDAY NIGHT THROUGH
TUESDAY NIGHT IN ASSOC/W A SATURATED WEDGE OF COOL AIR (CAD WEDGE)
IN THE LOWEST SEVERAL THOUSAND FEET OF THE ATMOSPHERE.
VFR CONDITIONS SHOULD RETURN BY MID-WEEK (WED) IN ASSOC/W A FRONTAL
PASSAGE. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...HARTFIELD
LONG TERM...SMITH
AVIATION...VINCENT
000
FXUS62 KRAH 211744
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1244 PM EST SAT NOV 21 2009
.SYNOPSIS...
A LOW PRESSURE SYSTEM IN THE NORTHWEST GULF OF MEXICO WILL MOVE
SLOWLY NORTHEAST TOWARD THE FLORIDA GULF COAST TONIGHT...BEFORE
WEAKENING AND REFORMING ALONG THE CAROLINA COAST SUNDAY NIGHT. THIS
WILL BRING INCREASING CLOUD COVER AND A GOOD CHANCE OF RAIN TO
CENTRAL NORTH CAROLINA BY SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 1200 PM SATURDAY...
16Z SFC ANALYSIS SHOWED 1024 MB HIGH PRESSURE CENTERED OVER OH/WV.
1010 MB LOW PRESSURE WAS CENTERED NEAR BUOY 42361 SOUTH OF LA.
ALOFT...12Z RAOB ANALYSIS SHOWED A SPLIT FLOW PATTERN ACROSS THE
CONUS. A SOUTHERN STREAM 500 MB LOW WAS CENTERED OVER SOUTHEAST TX.
A 90 KT SOUTHERN STREAM JET WAS NOTED ALONG THE SOUTHERN PERIPHERY
OF THE UPPER LOW OVER NORTHERN MEXICO AND THE NORTHERN GOMEX. A 100
KT NORTHERN STREAM JET WAS NOTED OVER THE NORTHERN MID-ATLANTIC
AHEAD OF A DEAMPLIFYING NORTHERN STREAM TROUGH OVER THE LOWER GREAT
LAKES. A RIDGE ALOFT WAS PRESENT OVER THE CENTRAL AND NORTHERN GREAT
PLAINS.
TODAY:
THE UPPER LOW CURRENTLY OVER SOUTHEAST TX IS PROGGED TO MOVE ENE
INTO LA BY 00Z THIS EVENING...WHILE THE ASSOC SFC LOW CURRENTLY OVER
THE NORTHWEST GOMEX IS PROGGED TO BE LOCATED JUST SOUTH OF THE LA
COAST BY THAT TIME. SFC HIGH PRESSURE IS EXPECTED TO REMAIN CENTERED
OVER PORTIONS OF THE MID-ATLANTIC...LOWER GREAT LAKES AND OH VALLEY
IN ASSOC/W CONFLUENT FLOW ALOFT...WITH A SFC RIDGE AXIS EXTENDING
SOUTH INTO THE CAROLINAS. EXPECT A STEADY INFLUX OF MID/UPPER LEVEL
CLOUD COVER THROUGHOUT THE DAY TODAY AS MOISTURE MOVES DOWNSTREAM OF
THE UPPER LOW ALONG THE GULF COAST INTO THE SOUTHEAST STATES AND
CAROLINAS. MOISTURE ADVECTION WILL GENERALLY BE LIMITED TO THE UPPER
LEVELS TODAY...AND CLOUD BASES WILL REMAIN AOA 15-18 KFT. LIFT TODAY
WILL BE EITHER VERY WEAK OR NON-EXISTENT ACROSS CENTRAL NC. ALTHOUGH
THERE IS CURRENTLY A NORTHERN STREAM JET ENTRANCE REGION N/NW OF
CENTRAL NC...THIS FEATURE IS PROGGED TO WEAKEN AND LIFT NORTHEAST
AWAY FROM THE AREA. MODEL ISENTROPIC FIELDS DO INDICATE INCREASING
ISENTROPIC LIFT ACROSS THE SOUTHEAST STATES THIS AFT/EVE AS A
925-850 MB WARM FRONT MOVES NORTHWARD TOWARD THE CENTRAL GULF COAST
AHEAD OF THE SFC/UPPER LOW IN LA. HOWEVER...ISENTROPIC LIFT WILL BE
WEAK AND CONFINED WELL SOUTH/SW OF CENTRAL NC. AS A RESULT...EXPECT
NO CHANCE FOR PRECIP THIS AFT/EVE. HIGH TEMPS WILL BE COMPLICATED
PRIMARILY BY BROKEN SKIES ASSOC/W UPPER LEVEL CLOUD COVER.
THICKNESSES WOULD ARGUE FOR HIGHS IN THE ~63F RANGE WITH FULL SUN...
HOWEVER...GIVEN WEAK LOW LEVEL NORTHEAST FLOW AND BROKEN UPPER LEVEL
CLOUD COVER...A RANGE OF 60-63F LOOKS MORE REASONABLE...ALTHOUGH
EVEN THAT COULD BE WARM BY 1-2F DEPENDING ON THE OPACITY OF CLOUD
COVER.
TONIGHT:
THE UPPER LOW CURRENTLY OVER SOUTHEAST TX IS PROGGED TO DEAMPLIFY
TONIGHT AS IT MOVES SLOWLY ENE INTO THE DEEP SOUTH. THE ATTENDANT
SFC LOW IS ALSO PROGGED TO WEAKEN A FEW MILLIBARS AS IT MOVES ALONG
A BAROCLINIC ZONE LOCATED OVER THE CENTRAL/NORTHEAST GULF COAST.
DESPITE THE WEAKENING SOUTHERN STREAM DYNAMICS...ISENTROPIC LIFT IS
EXPECTED TO STRENGTHEN OVER THE SOUTHEAST STATES INTO THE SOUTHERN
CAROLINAS TONIGHT AS A 925-850 MB WARM FRONT LIFTS NORTHWARD INTO
AL/GA AHEAD OF THE LOW PRESSURE SYSTEM ALONG THE GULF COAST. THE
BEST LOW LEVEL MOISTURE AND ISENTROPIC LIFT IS EXPECTED TO REMAIN
WELL S/SW OF CENTRAL NC THROUGH 12Z SUN...WITH PRECIP CHANCES
LARGELY CONFINED TO AL/GA AND PERHAPS SOUTHERN/WESTERN PORTIONS OF
SC. AS A RESULT...EXPECT A DRY FORECAST TO CONTINUE THROUGH THE
OVERNIGHT HOURS. MID/UPPER LEVEL CLOUD COVER WILL BE PERVASIVE
ACROSS THE AREA TONIGHT IN ASSOC/W THE LOW PRESSURE SYSTEM UPSTREAM
OF THE AREA...AND THAT WILL BE THE PRIMARY COMPLICATING FACTOR
W/REGARD TO LOW TEMPS. A MOS GUIDANCE BLEND LOOKS PRETTY
REASONABLE...WITH LOWS IN THE LOWER/MID 40S.
SUNDAY:
LATEST 12Z MODEL GUIDANCE CONTINUES TO SHOW THE 500 MB LOW
DEAMPLIFYING INTO A SHORTWAVE DURING THE DAY SUNDAY AS IT MOVES N/NE
INTO NORTHERN AL/GA AND EASTERN TN. THE ATTENDANT GULF COAST SFC LOW
IS PROGGED TO WEAKEN AS IT REMAINS CENTERED NEAR THE FL/AL COAST. AN
INVERTED SFC TROUGH/COASTAL FRONT IS EXPECTED TO SHARPEN OFF THE
SOUTHEAST/CAROLINA COAST DURING THE DAY SUN IN ASSOC/W WEAK UPPER
FORCING ASSOC/W THE DEAMPLIFYING SOUTHERN STREAM WAVE. SFC HIGH
PRESSURE OVER THE MID-ATLANTIC IS PROGGED TO STRENGTHEN AND SHIFT
NORTHEAST INTO NEW ENGLAND ON SUNDAY...WITH A PROMINENT SFC RIDGE
AXIS EXTENDING SOUTH INTO THE CAROLINAS. ALTHOUGH UPPER LEVEL LIFT
WILL BE RATHER ANEMIC SUNDAY...ISENTROPIC LIFT IN THE LOWER LEVELS
WILL BE STRENGTHENING FROM THE SOUTH/SW THROUGHOUT THE DAY AS THE
925-850MB WARM FRONT STALLS OUT JUST TO THE SOUTH IN SC AND THE
MSLP/HEIGHT GRADIENT TIGHTENS BETWEEN THE SFC RIDGE EXTENDING SOUTH
INTO THE AREA AND WEAK LOW PRESSURE OVER THE DEEP SOUTH AND
CAROLINA/SOUTHEAST COAST. BASED ON THE 12Z MODEL RUNS...THE TIMING
OF THE ARRIVAL OF PRECIP IS QUITE DELAYED COMPARED TO PREVIOUS
RUNS...WITH THE BEST CHANCE FOR RAIN STARTING IN THE SOUTH/SW IN THE
AFTERNOON...SPREADING NORTHWARD INTO THE TRIANGLE AREA BY OR SHORTLY
AFTER SUNSET. WILL SHOW HIGHEST POPS (CATEGORICAL/LIKELY) IN THE SW
PIEDMONT AND SANDHILLS...TAPERING DOWN TO SLIGHT CHANCE N/NE OF THE
TRIANGLE. RAINFALL AMOUNTS SHOULD BE NO HIGHER THAN 0.10-0.25" IN
THE SW PIEDMONT/SANDHILLS. TEMPERATURE FCST SOMEWHAT DIFFICULT ON
SUN...DEPENDING PRIMARILY ON THE ARRIVAL OF PRECIP. LATEST MOS
GUIDANCE HAS COME IN WARMER IN ALMOST ALL LOCATIONS...RANGING FROM
THE MID/UPPER 50S TO THE LOWER 60S...AND THAT LOOKS PRETTY
REASONABLE BASED ON THE DELAYED ONSET OF PRECIP. -VINCENT
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 315 AM SATURDAY...
AS THE UPPER SYSTEM LIFTS NORTHEAST THROUGH THE MOUNTAINS SUNDAY
NIGHT...LOW PRESSURE DEVELOPMENT OFF THE CAROLINAS OCCURS AND
BECOMES THE DOMINATE SURFACE LOW. GOOD MID LEVEL ISENTROPIC LIFT IN
THE MID LEVELS SHOULD KEEP RAIN CHANCES HIGH INTO SUNDAY NIGHT. MOST
MODELS DAMP OUT THE PARENT LOW PRESSURE TROUGH AS IT MOVES NORTHEAST
AND KEEP THE SURFACE LOW WEAKER THAN THE CANADIAN AS IT APPROACHES
CAPE HATTERAS. RAINFALL PERHAPS TWO TENTHS INCH NORTHWEST TO FOUR
TENTHS SOUTHEAST SUNDAY NIGHT.
WINDS WEAKEN LATE SUNDAY NIGHT INTO MONDAY AND HEAVIER
PRECIPITATION MAY MISS US TO THE EAST MONDAY. PRECIPITATION MAY
LINGER LONGEST IN THE NORTHEAST WITH THE EXITING SURFACE LOW BUT
RAINFALL AMOUNTS OF ONE TENTH INCH OR LESS EAST... AND MUCH LESS
TO THE WEST. OF COURSE IF THE LOW TRACKS CLOSER TO THE COAST...
THESE AMOUNTS ARE UNDERDONE. ONLY A SLIGHT RAIN CHANCE IN THE
NORTHEAST WITH THE EXITING LOW MONDAY NIGHT.
OVERNIGHT LOWS 45 TO 50 SUNDAY NIGHT... AND MOSTLY MID 40S TUESDAY
NIGHT. SUNDAY HIGH TEMPERATURES NEAR 50 NORTHWEST TO UPPER 50S
SOUTHEAST. IF A COLD AIR MASS DAMMING WEDGE SETS UP AS EXPECTED
MONDAY...A LOW OVERCAST WITH LIGHT RAIN OR DRIZZLE POSSIBLE. THE
CURRENT FORECAST TEN DEGREE DIURNAL RISE TO MONDAY AFTERNOON WOULD
NEED TO BE DROPPED TO THREE TO SIX DEGREES IF CLOUDS ARE ABLE TO
PERSIST INTO EARLY MONDAY EVENING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 315 AM FRIDAY...
ANY LIGHT PRECIP LINGERING INTO MONDAY NIGHT SHOULD BE GONE BY
TUESDAY MORNING...AS SOUTHWESTERLY MID LEVEL FLOW USHERS IN DRIER
AIR ABOVE THE REMAINING CAD AIRMASS. THE POSSIBILITY LINGERING LOW
CLOUDS COULD COMPLICATE THE TEMPERATURE FORECAST ON TUESDAY AS SOME
MOISTURE REMAINS BELOW A SUBSIDENCE INVERSION BENEATH DEVELOPING
SHORTWAVE RIDGING ALOFT. WILL STICK WITH MOS VALUES WITH HIGHS
64-70.
THE FORECAST GETS QUITE A BIT MORE COMPLICATED BEYOND TUESDAY...WITH
THE HANDLING OF A SHORTWAVE EXPECTED TO ENTER THE PACIFIC NORTHWEST
ON MONDAY AND EMERGE OVER THE NORTH CENTRAL PLAINS BY WED. THE
GENERAL TREND IS FOR THE DEVELOPMENT OF A HIGH AMPLITUDE LONGWAVE
TROUGH BY THE END OF THE WEEK...AND WHILE BOTH THE GFS AND ECMWF
RESOLVE SUCH A SOLUTION...THEY CURRENTLY GET THE SIMILAR ANSWER
THROUGH SOMEWHAT DIFFERENT SCENARIOS. THE GFS SENDS THE
AFOREMENTIONED SHORTWAVE ACROSS THE UPPER MIDWEST AND THE LIFTS THE
SYSTEM INTO ONTARIO BY THURSDAY...PUSHING A DRY COLD FRONT INTO
CENTRAL NC WED NIGHT. THIS IS FOLLOWED BY A SECOND SHORTWAVE THAT
DIVES SOUTH THROUGH THE MIDWEST...BUT WITH NO MORE TO WORK
WITH....POINTS EAST OF THE MOUNTAINS STAY DRY EVEN AS A SURFACE WAVE
IS INDUCED OFFSHORE THURSDAY MORNING. THE ECMWF ON THE OTHER HAND
IS MUCH SLOWER WITH THE FIRST SHORTWAVE...ALLOWING MORE MOISTURE TO
BE PULLED NORTH OVER A PERSISTENT SURFACE RIDGE ALONG THE EASTERN
SEABOARD. CYCLOGENESIS ALONG THE COAST SUBSEQUENTLY OCCURS CLOSER
TO THE COAST THURSDAY MORNING WITH LESS EASTWARD PROGRESSION OF THE
SURFACE FRONT...AND THUS THE ECMWF PRODUCES PRECIP OVER THE EASTERN
THIRD OF NC. GIVEN THESE CONTINUED MODEL INCONSISTENCIES...FEEL THE
BEST COURSE OF ACTION IS TO SHOW BELOW NORMAL TEMPS FOR THE END OF
THE WEEK...CONTINUING WITH HIGHER SLIGHT CHANCE POPS IN THE EAST
UNTIL SOME SORT OF MODEL CONVERGENCE BEGINS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1245 PM SATURDAY...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. UPPER LEVEL
CLOUD COVER WILL CONTINUE TO INCREASE OVER THE AREA IN ADVANCE OF A
STORM SYSTEM CURRENTLY LOCATED ALONG THE NORTHWEST GULF COAST.
CEILINGS ARE EXPECTED TO REMAIN IN THE 15-18 KFT RANGE THROUGH
TONIGHT. CEILINGS WILL BEGIN TO LOWER DURING THE DAY SUNDAY...
HOWEVER...ANY MVFR/IFR CEILINGS AND RAIN ARE EXPECTED TO HOLD OFF
UNTIL AFTER THE END OF THE CURRENT TAF PERIOD.
MVFR/IFR CONDITIONS IN RAIN ARE EXPECTED TO AFFECT MOST OR ALL OF
THE AREA FROM 00Z MON THROUGH 00Z TUE...WITH MVFR/IFR AND PERHAPS
LIFR CONDITIONS IN LOW CEILINGS/FOG/DRIZZLE MONDAY NIGHT THROUGH
TUESDAY NIGHT IN ASSOC/W A SATURATED WEDGE OF COOL AIR (CAD WEDGE)
IN THE LOWEST SEVERAL THOUSAND FEET OF THE ATMOSPHERE.
VFR CONDITIONS SHOULD RETURN BY MID-WEEK (WED) IN ASSOC/W A FRONTAL
PASSAGE. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...99
LONG TERM...SMITH
AVIATION...VINCENT
000
FXUS62 KILM 211724
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1224 PM EST SAT NOV 21 2009
.SYNOPSIS...
INCREASING MOISTURE FROM THE GULF OF MEXICO WILL ENTER THE CAROLINAS
SUNDAY INTO MONDAY WITH WIDESPREAD RAIN EXPECTED. A BRIEF WARMUP IS
EXPECTED TUESDAY AND WEDNESDAY. A STRONG COLD FRONT THURSDAY WILL
USHER IN SOME COLDER AIR FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 AM SATURDAY...PERIODS OF MULTI-LAYERED CLOUDS WILL KEEP
SKIES VARIABLY CLOUDY TODAY WITH A COOL NORTHEAST BREEZE IN PLACE.
LOW PRESSURE DEVELOPED OVERNIGHT ALONG A NEARLY STATIONARY FRONT
WELL OFFSHORE. THIS LED TO AN ENHANCEMENT IN THE LOW-LEVEL NORTHEAST
FLOW OVERNIGHT. THIS LOW WILL MOVE NORTHEAST AND AWAY FROM THE AREA
THIS AFTERNOON...BUT NEW LOW PRESSURE WILL DEVELOP LATE TONIGHT
ALONG THE EASTERN GULF COAST.
IT APPEARS ENOUGH DRY AIR WILL REMAIN ENTRENCHED IN THE SUB-CLOUD
LAYER TO PREVENT MEASURABLE PRECIPITATION FROM DEVELOPING ACROSS OUR
AREA THROUGH DAYBREAK SUNDAY. THIS IS IN AGREEMENT WITH THE PREVIOUS
FORECAST AND ALSO THE 06Z RUNS OF THE NAM AND GFS. THE 06Z NAM WAS
NOTABLE IN ITS DEPICTION OF A VERY DEEP DRY SUB-CLOUD LAYER MOVING
IN LATE TONIGHT WHICH COULD ACTUALLY DELAY THE ONSET OF
PRECIPITATION WELL INTO THE DAY SUNDAY. WE WILL REVISIT THIS
POTENTIAL WITH THE AFTERNOON FORECAST UPDATE.
THE INCOMING AIRMASS IS QUITE CHILLY AND EVEN WITH FILTERED SUNSHINE
WE WILL ONLY REACH THE LOWER TO MID 60S THIS AFTERNOON. THE PREVIOUS
FORECAST REMAINS IN GREAT SHAPE AND NO SIGNIFICANT CHANGES WERE
NEEDED.
&&
.SHORT TERM/SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...
MOISTURE OVERRUNNING NORTHEASTERLY SURFACE FLOW ASSOCIATED WITH
WEDGE OF HIGH PRESSURE WILL BRING PLENTY OF CLOUDINESS TO START THE
PERIOD. INCREASING ISENTROPIC UPGLIDE WILL ALSO RAMP UP RAIN
CHANCES...ENDING UP IN THE CATEGORICAL RANGE BY EVENING. QPF
FORECAST IS STILL A LITTLE UNCERTAIN AS GUIDANCE HAS REALLY BACKED
OFF WITH RAINFALL WHEN COMPARED TO PREVIOUS DAYS. RAIN CHANCES
REMAIN FAIRLY HIGH SUNDAY NIGHT AS THE WEAKENING LOW JUMPS TO THE
EASTERN SIDE OF THE WEDGE AND ENDS UP OFFSHORE. SOON THEREAFTER RAIN
CHANCES SHOULD TAPER OFF FROM WEST TO EAST EARLY MONDAY. CLOUDS AND
POSSIBLY DRIZZLE COULD LINGER INTO THE MORNING HOURS. MIGHT EVEN SEE
A TREND TOWARDS OVERALL SLOWER PROGRESSION WHICH COULD MEAN DRIZZLE
AND CLOUDS LINGER MOST OF THE DAY. HAVE UNDERCUT GUIDANCE ON MONDAY
HIGH TEMPS.
&&
.LONG TERM/TUESDAY THROUGH FRIDAY/...
AS OF 3 PM SATURDAY...
A WEAK UPPER RIDGE MANAGES TO BUILD ON TUESDAY AND THIS SHOULD BRING
A MILD AFTERNOON. WEDNESDAY MAY ALSO BRING HIGHS IN THE LOW 70S
AHEAD OF WHAT WILL END UP BEING A PRETTY STRONG COLD FRONT ON
THURSDAY. LITTLE TO NO MOISTURE FLOW AHEAD OF THE FRONT SO ITS
PASSAGE SHOULD BE DRY. THE ECWMF HAS INDICATED OTHERWISE FOR A FEW
RUNS NOW BUT THIS MODEL HAS BEEN DISPLAYING A VERY WET BIAS FOR SOME
TIME LOCALLY IN SUCH SETUPS. DRY AND COOL WEATHER FOR THE REST OF
THE PD WITH HIGHS STRUGGLING TO LOW 60S BY DAY AND UPPER 30S AT
NIGHT.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
MID LEVEL STRATUS ASSOCIATED WITH WEAK LOW PRESSURE WAVE OFFSHORE IS
STRUGGLING TO ADVECT INLAND...AND COASTAL TERMINALS HAVE ONLY
REPORTED SCT CIGS TODAY. STILL EXPECT BKN 5K FOOT CIGS AT
ILM/CRE/MYR THROUGH THE AFTN AND INTO TONIGHT. FLO/LBT ONLY DEALING
WITH HIGH LEVEL CI STREAMING IN AHEAD OF DEVELOPING GULF OF MEXICO
LOW PRESSURE. WINDS HAVE BEEN GENERALLY OUT OF THE N/NE AT 8 TO 14
KT ACROSS THE REGION...AND THIS WILL CONTINUE THROUGH THE AFTN WHILE
INSOLATION HELPS PROMOTE MIXING. TONIGHT WINDS WILL DECREASE...BUT
LIKELY NOT DECOUPLE...SO EXPECT NE WINDS AT 4 TO 7 KT THROUGH THE
OVERNIGHT. NO FOG TONIGHT.
VFR WILL BE THE RULE AT ALL TERMINALS THROUGH THE TAF PERIOD. ONLY
FORECAST CONCERN WILL BE DEVELOPMENT OF RAIN TOMORROW AFTN. GUIDANCE
CONTINUES TO DELAY ONSET OF PRECIPITATION...SO HAVE ONLY INTRODUCED
VCSH TO FLO BY 18Z TOMORROW. ALL OTHER TERMINALS SHOULD REMAIN DRY
THROUGH THE NEXT 24 HOURS...WITH CEILINGS DEVELOPING AROUND 4K TO 5K
FEET EVERYWHERE. WILL LET FUTURE TAFS ADDRESS RAIN POTENTIAL AS THE
EVENT GETS CLOSER.
EXTENDED OUTLOOK...POTENTIAL IFR DUE TO SHOWERS AND LOW CEILINGS
SUNDAY AND MONDAY. FOG POSSIBLE TUESDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 8 AM SATURDAY...LOW PRESSURE WELL OFF THE SOUTH CAROLINA COAST
AND HIGH PRESSURE OVER THE GREAT LAKES ARE SETTING THE STAGE FOR A
SUSTAINED PERIOD OF NORTHEAST WINDS LASTING THROUGH THE NEXT SEVERAL
DAYS. A PINCHED GRADIENT DEVELOPED OVERNIGHT WITH WIND GUSTS UP TO
30 KNOTS AT THE NEARSHORE WRIGHTSVILLE BEACH BUOY. WINDS HAVE
DIMINISHED A LITTLE AND WE SHOULD DROP TO A RELATIVE LULL IN WIND
SPEEDS THIS AFTERNOON. LOW PRESSURE TONIGHT WILL DEVELOP ALONG THE
EASTERN GULF COAST WHICH WILL LEAD TO AN ENHANCEMENT OF THE LOCAL
PRESSURE GRADIENT LATE TONIGHT.
SEAS ARE STILL RUNNING 7 FT AT THE FRYING PAN SHOALS BUOY...AND 5 FT
AT THE NEARSHORE WRIGHTSVILLE BEACH BUOY. THIS MATCHES VERY WELL
WITH THE LOCAL SWAN WAVE MODEL AND NO SIGNIFICANT CHANGES ARE NEEDED
TO THE PREVIOUS FORECAST.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...
SURFACE HIGH PRESSURE WEDGE IN CONTROL ON SUNDAY TO BRING A MODERATE
GRADIENT WIND. SMALL CRAFT ADVISORY FROM NEAR TERM HAS BEEN EXTENDED
THROUGH SUNDAY FOR NORTHERN TWO ZONES AS 6 FT SEAS AFFECT THE OUTER
REACHES ALONG FRYING PAN SHOALS. WAVE SHADOWING WILL PROBABLY
PRECLUDE THIS OVER SOUTHERN WATERS. A FLAT WAVE OF LOW PRESSURE WILL
RIDE UP THE EAST SIDE OF THE WEDGE SUNDAY NIGHT INTO MONDAY. THIS
WILL SLIGHTLY TAPER THE GRADIENT AND COULD LOWER THE SEAS ENOUGH TO
DROP ANY ADVISORIES. WEDGE WEAKENS BUT REMAINS IN PLACE FOR THE
REMAINDER OF MONDAY AND MONDAY NIGHT KEEPING WINDS WITH A NORTHERLY
COMPONENT.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 PM SATURDAY...
LOOKS LIKE A FAIRLY QUIET PATTERN FOR MOST OF THE PERIOD. HIGH
PRESSURE REMAINS TO THE NORTH TUESDAY BRINGING A LIGHT NORTHERLY
WIND AND SEAS IN THE 2 TO 3 FT RANGE. CHANGES MAY BE UNDERWAY COME
WEDNESDAY AS THE HIGH BEGINS TO LIFT OUT AHEAD OF AN APPROACHING
COLD FRONT. THE TIMING OF THIS FRONT AND THE EVOLUTION OF SURFACE
FEATURES ASSOCIATED WITH IT IS HIGHLY UNCERTAIN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR AMZ256.
SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...MBB/TRA
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...JDW
000
FXUS62 KRAH 211658
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1158 AM EST SAT NOV 21 2009
.SYNOPSIS...
A LOW PRESSURE SYSTEM IN THE NORTHWEST GULF OF MEXICO WILL MOVE
SLOWLY NORTHEAST TOWARD THE FLORIDA GULF COAST TONIGHT...BEFORE
WEAKENING AND REFORMING ALONG THE CAROLINA COAST SUNDAY NIGHT. THIS
WILL BRING INCREASING CLOUD COVER AND A GOOD CHANCE OF RAIN TO
CENTRAL NORTH CAROLINA BY SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 1200 PM SATURDAY...
16Z SFC ANALYSIS SHOWED 1024 MB HIGH PRESSURE CENTERED OVER OH/WV.
1010 MB LOW PRESSURE WAS CENTERED NEAR BUOY 42361 SOUTH OF LA.
ALOFT...12Z RAOB ANALYSIS SHOWED A SPLIT FLOW PATTERN ACROSS THE
CONUS. A SOUTHERN STREAM 500 MB LOW WAS CENTERED OVER SOUTHEAST TX.
A 90 KT SOUTHERN STREAM JET WAS NOTED ALONG THE SOUTHERN PERIPHERY
OF THE UPPER LOW OVER NORTHERN MEXICO AND THE NORTHERN GOMEX. A 100
KT NORTHERN STREAM JET WAS NOTED OVER THE NORTHERN MID-ATLANTIC
AHEAD OF A DEAMPLIFYING NORTHERN STREAM TROUGH OVER THE LOWER GREAT
LAKES. A RIDGE ALOFT WAS PRESENT OVER THE CENTRAL AND NORTHERN GREAT
PLAINS.
TODAY:
THE UPPER LOW CURRENTLY OVER SOUTHEAST TX IS PROGGED TO MOVE ENE
INTO LA BY 00Z THIS EVENING...WHILE THE ASSOC SFC LOW CURRENTLY OVER
THE NORTHWEST GOMEX IS PROGGED TO BE LOCATED JUST SOUTH OF THE LA
COAST BY THAT TIME. SFC HIGH PRESSURE IS EXPECTED TO REMAIN CENTERED
OVER PORTIONS OF THE MID-ATLANTIC...LOWER GREAT LAKES AND OH VALLEY
IN ASSOC/W CONFLUENT FLOW ALOFT...WITH A SFC RIDGE AXIS EXTENDING
SOUTH INTO THE CAROLINAS. EXPECT A STEADY INFLUX OF MID/UPPER LEVEL
CLOUD COVER THROUGHOUT THE DAY TODAY AS MOISTURE MOVES DOWNSTREAM OF
THE UPPER LOW ALONG THE GULF COAST INTO THE SOUTHEAST STATES AND
CAROLINAS. MOISTURE ADVECTION WILL GENERALLY BE LIMITED TO THE UPPER
LEVELS TODAY...AND CLOUD BASES WILL REMAIN AOA 15-18 KFT. LIFT TODAY
WILL BE EITHER VERY WEAK OR NON-EXISTENT ACROSS CENTRAL NC. ALTHOUGH
THERE IS CURRENTLY A NORTHERN STREAM JET ENTRANCE REGION N/NW OF
CENTRAL NC...THIS FEATURE IS PROGGED TO WEAKEN AND LIFT NORTHEAST
AWAY FROM THE AREA. MODEL ISENTROPIC FIELDS DO INDICATE INCREASING
ISENTROPIC LIFT ACROSS THE SOUTHEAST STATES THIS AFT/EVE AS A
925-850 MB WARM FRONT MOVES NORTHWARD TOWARD THE CENTRAL GULF COAST
AHEAD OF THE SFC/UPPER LOW IN LA. HOWEVER...ISENTROPIC LIFT WILL BE
WEAK AND CONFINED WELL SOUTH/SW OF CENTRAL NC. AS A RESULT...EXPECT
NO CHANCE FOR PRECIP THIS AFT/EVE. HIGH TEMPS WILL BE COMPLICATED
PRIMARILY BY BROKEN SKIES ASSOC/W UPPER LEVEL CLOUD COVER.
THICKNESSES WOULD ARGUE FOR HIGHS IN THE ~63F RANGE WITH FULL SUN...
HOWEVER...GIVEN WEAK LOW LEVEL NORTHEAST FLOW AND BROKEN UPPER LEVEL
CLOUD COVER...A RANGE OF 60-63F LOOKS MORE REASONABLE...ALTHOUGH
EVEN THAT COULD BE WARM BY 1-2F DEPENDING ON THE OPACITY OF CLOUD
COVER.
TONIGHT:
THE UPPER LOW CURRENTLY OVER SOUTHEAST TX IS PROGGED TO DEAMPLIFY
TONIGHT AS IT MOVES SLOWLY ENE INTO THE DEEP SOUTH. THE ATTENDANT
SFC LOW IS ALSO PROGGED TO WEAKEN A FEW MILLIBARS AS IT MOVES ALONG
A BAROCLINIC ZONE LOCATED OVER THE CENTRAL/NORTHEAST GULF COAST.
DESPITE THE WEAKENING SOUTHERN STREAM DYNAMICS...ISENTROPIC LIFT IS
EXPECTED TO STRENGTHEN OVER THE SOUTHEAST STATES INTO THE SOUTHERN
CAROLINAS TONIGHT AS A 925-850 MB WARM FRONT LIFTS NORTHWARD INTO
AL/GA AHEAD OF THE LOW PRESSURE SYSTEM ALONG THE GULF COAST. THE
BEST LOW LEVEL MOISTURE AND ISENTROPIC LIFT IS EXPECTED TO REMAIN
WELL S/SW OF CENTRAL NC THROUGH 12Z SUN...WITH PRECIP CHANCES
LARGELY CONFINED TO AL/GA AND PERHAPS SOUTHERN/WESTERN PORTIONS OF
SC. AS A RESULT...EXPECT A DRY FORECAST TO CONTINUE THROUGH THE
OVERNIGHT HOURS. MID/UPPER LEVEL CLOUD COVER WILL BE PERVASIVE
ACROSS THE AREA TONIGHT IN ASSOC/W THE LOW PRESSURE SYSTEM UPSTREAM
OF THE AREA...AND THAT WILL BE THE PRIMARY COMPLICATING FACTOR
W/REGARD TO LOW TEMPS. A MOS GUIDANCE BLEND LOOKS PRETTY
REASONABLE...WITH LOWS IN THE LOWER/MID 40S.
SUNDAY:
LATEST 12Z MODEL GUIDANCE CONTINUES TO SHOW THE 500 MB LOW
DEAMPLIFYING INTO A SHORTWAVE DURING THE DAY SUNDAY AS IT MOVES N/NE
INTO NORTHERN AL/GA AND EASTERN TN. THE ATTENDANT GULF COAST SFC LOW
IS PROGGED TO WEAKEN AS IT REMAINS CENTERED NEAR THE FL/AL COAST. AN
INVERTED SFC TROUGH/COASTAL FRONT IS EXPECTED TO SHARPEN OFF THE
SOUTHEAST/CAROLINA COAST DURING THE DAY SUN IN ASSOC/W WEAK UPPER
FORCING ASSOC/W THE DEAMPLIFYING SOUTHERN STREAM WAVE. SFC HIGH
PRESSURE OVER THE MID-ATLANTIC IS PROGGED TO STRENGTHEN AND SHIFT
NORTHEAST INTO NEW ENGLAND ON SUNDAY...WITH A PROMINENT SFC RIDGE
AXIS EXTENDING SOUTH INTO THE CAROLINAS. ALTHOUGH UPPER LEVEL LIFT
WILL BE RATHER ANEMIC SUNDAY...ISENTROPIC LIFT IN THE LOWER LEVELS
WILL BE STRENGTHENING FROM THE SOUTH/SW THROUGHOUT THE DAY AS THE
925-850MB WARM FRONT STALLS OUT JUST TO THE SOUTH IN SC AND THE
MSLP/HEIGHT GRADIENT TIGHTENS BETWEEN THE SFC RIDGE EXTENDING SOUTH
INTO THE AREA AND WEAK LOW PRESSURE OVER THE DEEP SOUTH AND
CAROLINA/SOUTHEAST COAST. BASED ON THE 12Z MODEL RUNS...THE TIMING
OF THE ARRIVAL OF PRECIP IS QUITE DELAYED COMPARED TO PREVIOUS
RUNS...WITH THE BEST CHANCE FOR RAIN STARTING IN THE SOUTH/SW IN THE
AFTERNOON...SPREADING NORTHWARD INTO THE TRIANGLE AREA BY OR SHORTLY
AFTER SUNSET. WILL SHOW HIGHEST POPS (CATEGORICAL/LIKELY) IN THE SW
PIEDMONT AND SANDHILLS...TAPERING DOWN TO SLIGHT CHANCE N/NE OF THE
TRIANGLE. RAINFALL AMOUNTS SHOULD BE NO HIGHER THAN 0.10-0.25" IN
THE SW PIEDMONT/SANDHILLS. TEMPERATURE FCST SOMEWHAT DIFFICULT ON
SUN...DEPENDING PRIMARILY ON THE ARRIVAL OF PRECIP. LATEST MOS
GUIDANCE HAS COME IN WARMER IN ALMOST ALL LOCATIONS...RANGING FROM
THE MID/UPPER 50S TO THE LOWER 60S...AND THAT LOOKS PRETTY
REASONABLE BASED ON THE DELAYED ONSET OF PRECIP. -VINCENT
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 315 AM SATURDAY...
AS THE UPPER SYSTEM LIFTS NORTHEAST THROUGH THE MOUNTAINS SUNDAY
NIGHT...LOW PRESSURE DEVELOPMENT OFF THE CAROLINAS OCCURS AND
BECOMES THE DOMINATE SURFACE LOW. GOOD MID LEVEL ISENTROPIC LIFT IN
THE MID LEVELS SHOULD KEEP RAIN CHANCES HIGH INTO SUNDAY NIGHT. MOST
MODELS DAMP OUT THE PARENT LOW PRESSURE TROUGH AS IT MOVES NORTHEAST
AND KEEP THE SURFACE LOW WEAKER THAN THE CANADIAN AS IT APPROACHES
CAPE HATTERAS. RAINFALL PERHAPS TWO TENTHS INCH NORTHWEST TO FOUR
TENTHS SOUTHEAST SUNDAY NIGHT.
WINDS WEAKEN LATE SUNDAY NIGHT INTO MONDAY AND HEAVIER
PRECIPITATION MAY MISS US TO THE EAST MONDAY. PRECIPITATION MAY
LINGER LONGEST IN THE NORTHEAST WITH THE EXITING SURFACE LOW BUT
RAINFALL AMOUNTS OF ONE TENTH INCH OR LESS EAST... AND MUCH LESS
TO THE WEST. OF COURSE IF THE LOW TRACKS CLOSER TO THE COAST...
THESE AMOUNTS ARE UNDERDONE. ONLY A SLIGHT RAIN CHANCE IN THE
NORTHEAST WITH THE EXITING LOW MONDAY NIGHT.
OVERNIGHT LOWS 45 TO 50 SUNDAY NIGHT... AND MOSTLY MID 40S TUESDAY
NIGHT. SUNDAY HIGH TEMPERATURES NEAR 50 NORTHWEST TO UPPER 50S
SOUTHEAST. IF A COLD AIR MASS DAMMING WEDGE SETS UP AS EXPECTED
MONDAY...A LOW OVERCAST WITH LIGHT RAIN OR DRIZZLE POSSIBLE. THE
CURRENT FORECAST TEN DEGREE DIURNAL RISE TO MONDAY AFTERNOON WOULD
NEED TO BE DROPPED TO THREE TO SIX DEGREES IF CLOUDS ARE ABLE TO
PERSIST INTO EARLY MONDAY EVENING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 315 AM FRIDAY...
ANY LIGHT PRECIP LINGERING INTO MONDAY NIGHT SHOULD BE GONE BY
TUESDAY MORNING...AS SOUTHWESTERLY MID LEVEL FLOW USHERS IN DRIER
AIR ABOVE THE REMAINING CAD AIRMASS. THE POSSIBILITY LINGERING LOW
CLOUDS COULD COMPLICATE THE TEMPERATURE FORECAST ON TUESDAY AS SOME
MOISTURE REMAINS BELOW A SUBSIDENCE INVERSION BENEATH DEVELOPING
SHORTWAVE RIDGING ALOFT. WILL STICK WITH MOS VALUES WITH HIGHS
64-70.
THE FORECAST GETS QUITE A BIT MORE COMPLICATED BEYOND TUESDAY...WITH
THE HANDLING OF A SHORTWAVE EXPECTED TO ENTER THE PACIFIC NORTHWEST
ON MONDAY AND EMERGE OVER THE NORTH CENTRAL PLAINS BY WED. THE
GENERAL TREND IS FOR THE DEVELOPMENT OF A HIGH AMPLITUDE LONGWAVE
TROUGH BY THE END OF THE WEEK...AND WHILE BOTH THE GFS AND ECMWF
RESOLVE SUCH A SOLUTION...THEY CURRENTLY GET THE SIMILAR ANSWER
THROUGH SOMEWHAT DIFFERENT SCENARIOS. THE GFS SENDS THE
AFOREMENTIONED SHORTWAVE ACROSS THE UPPER MIDWEST AND THE LIFTS THE
SYSTEM INTO ONTARIO BY THURSDAY...PUSHING A DRY COLD FRONT INTO
CENTRAL NC WED NIGHT. THIS IS FOLLOWED BY A SECOND SHORTWAVE THAT
DIVES SOUTH THROUGH THE MIDWEST...BUT WITH NO MORE TO WORK
WITH....POINTS EAST OF THE MOUNTAINS STAY DRY EVEN AS A SURFACE WAVE
IS INDUCED OFFSHORE THURSDAY MORNING. THE ECMWF ON THE OTHER HAND
IS MUCH SLOWER WITH THE FIRST SHORTWAVE...ALLOWING MORE MOISTURE TO
BE PULLED NORTH OVER A PERSISTENT SURFACE RIDGE ALONG THE EASTERN
SEABOARD. CYCLOGENESIS ALONG THE COAST SUBSEQUENTLY OCCURS CLOSER
TO THE COAST THURSDAY MORNING WITH LESS EASTWARD PROGRESSION OF THE
SURFACE FRONT...AND THUS THE ECMWF PRODUCES PRECIP OVER THE EASTERN
THIRD OF NC. GIVEN THESE CONTINUED MODEL INCONSISTENCIES...FEEL THE
BEST COURSE OF ACTION IS TO SHOW BELOW NORMAL TEMPS FOR THE END OF
THE WEEK...CONTINUING WITH HIGHER SLIGHT CHANCE POPS IN THE EAST
UNTIL SOME SORT OF MODEL CONVERGENCE BEGINS.
&&
.AVIATION /12Z SATURDAY THROUGH THURSDAY/...
AS OF 645 AM SATURDAY...
WITH MODELS TRENDING SLOWER ON THE ARRIVAL OF A STORM SYSTEM
CURRENTLY OVER THE WESTERN GULF COAST...VFR CONDITIONS WILL PREVAIL
THROUGH THE VALID TAF FORECAST. SCT TO BKN CIRRUS AND EVENTUALLY
CIRROSTRATUS WILL DRIFT ACROSS THE REGION TODAY AND INTO
TONIGHT...ALL AHEAD OF A STORM SYSTEM SET TO IMPACT CENTRAL NC FROM
THE SOUTHWEST DURING THE DAY SUNDAY. AT THE SURFACE...HIGH PRESSURE
TO OUR NORTH WILL SETTLE OVER NEW ENGLAND...EXTENDING A RIDGE OF DRY
AIR DOWN THE EAST COAST....AND PROVIDING A LIGHT NE WIND.
AS THE STORM SYSTEM APPROACHES FROM THE SOUTHWEST SUNDAY MORNING
CEILINGS WILL EVENTUALLY LOWER TO MVFR OR IFR LEVELS SUNDAY THROUGH
MONDAY...WITH PERIODS OF RAIN POSSIBLE AT ALL TAF SITES. AT LEAST
MVFR CEILINGS ARE EXPECTED TO PERSIST THROUGH LATE MONDAY...BEFORE A
COASTAL LOW MOVES AWAY FROM NC AND PULLS DRIER AIR INTO THE AREA.
CONDITIONS ARE EXPECTED TO REMAIN VFR FOR THE MOST THROUGH THE
BALANCE OF THE WEEK...ALTHOUGH THERE IS THE POTENTIAL FOR ANOTHER
WEATHER SYSTEM TO EFFECT MAINLY EASTERN TERMINALS BY THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...99
LONG TERM...SMITH
AVIATION...SMITH
000
FXUS62 KMHX 211543
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
1043 AM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...THEN SLIDE
OFFSHORE TONIGHT. LOW PRESSURE WILL DEVELOP JUST OFFSHORE LATE
SUNDAY AND SUNDAY NIGHT...THEN LIFT NE ON MONDAY. HIGH PRESSURE
WILL REBUILD OVER THE AREA TUESDAY AND WEDNESDAY. A COLD FRONT
WILL APPROACH FROM THE WEST ON THURSDAY AND MOVE OFFSHORE
FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DESPITE THE COOL NE FLOW REGIME...PARTIAL SUNSHINE AND WEAK
THICKNESS RIDGING ALOFT WILL ALLOW TEMPS TO RISE ANTHR 5-10 DEGS
THIS AFTN. NAM FCST SOUNDING CONT TO SHOW A NEARLY SATURATED LYR
NEAR 5000 FT THIS AFTN SO EXPECT WILL SEE DECENT AMOUNT OF STRATO-
CU...WILL ALSO HAVE SOME HIGH CLOUDS TODAY BUT EXPECT ENUF PEAKS
OF SUN TO GET HIGHS IN THE 60 TO 65 DGR RANGE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS OF 2 AM SAT...CLOUDS WILL THICKEN TONIGHT AS BEGIN TO SEE LOW
LVL MOISTURE INCREASE PLUS WILL HAVE SOME MID/HIGH CLOUDS WELL
AHEAD OF APPROACHING SRT WAVE. CONT PREV FCST OF SLIGHT POP LATE
TONIGHT SRN TIER. LOWS MAINLY UPR 40S TO LOWER 50S. RAIN WILL BE
INCREASING FROM SW TO NE SUNDAY AS INSENT LIFT INCREASES OVER THE
AREA AS CSTL FRONT TAKES SHAPE JUST OFFSHORE AHEAD OF APPROACHING
SRT WAVE. CONT LIKELY POPS INLAND TO CHC NE CST LATER SUNDAY. SUN
NIGHT LOOKS WET AS ISENT LIFT CONTS WITH INCREASING MID/UPR
SUPPORT WITH SRT WAVE PASSING BY TO THE NW. HAVE CATEGORICAL POPS
ALL AREAS SUN NIGHT. RAIN WILL GRAD DIMINISH FROM SW TO NE MON
HOWEVER WILL STILL HAVE GOOD CVRG EARLY AND CONT CATEGORICAL NE
CST TO LIKELY POPS ELSEWHERE WITH POPS DECREASING TO CHC LATE.
TOTAL QPF FROM THIS EVENT LOOKS TO AVG OUT IN 0.5 TO 1 INCH RANGE AND
DESPITE VERY WET GROUND MANY AREAS SHLD NOT CAUSE SIGNIFICANT
PROBLEMS. HIGHS BOTH SUN AND MON WITH CLOUDS...PRECIP AND NE WINDS
WILL BE MAINLY IN THE UPPER 50S TO LOWER 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 2 AM SAT...ANY LINGERING LIGHT RAIN/DRIZZLE WILL END MON
NIGHT. WITH HIGH PRES BUILDING IN TUE AND WED EXPECT DRY
CONDITIONS. IMPRESSIVE SRT WAVE/COLD FRONT WILL APPROACH THU AND
MOVE OFFSHORE FRI. MDLS DIFFER WITH GFS SHOWING LIMITED MOISTURE
AND BULK OF PRECIP OFFSHORE. EMCWF IS WETTER...ESPCLY CST WITH
MOISTURE COMING IN OFF ATLC. CURRENTLY HAVE CHC POPS THU AND WILL
NOT CHANGE UNTIL GET MORE CLARITY FROM MDLS. COOLER AND DRY FRI IN
WAKE OF FRONT/SRT WAVE.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
AS OF 915 AM...A MIX OF LAYERED CLOUDS EXPECTED FOR THE REMAINDER OF
THE DAY WITH VFR CEILINGS. TONIGHT...HIGHER CLOUDS WILL SINK INTO A
MID DECK WHICH ALONG WITH LIGHT WINDS WILL HELP INHIBIT FOG DESPITE
HIGHER DEWPOINTS.
LOW PRES MOVING UP FROM SW WILL PRODUCE DETERIORATING CONDITIONS
LATE SUN...WITH WDSPRD IFR SUN NIGHT AND MON. LOWER CIGS LIKELY TO
PERSIST INTO TUE DUE TO WEDGE CONDITIONS IN WAKE OF DEPARTED LOW
PRES.
&&
.MARINE...
AS OF 915 AM...WE WILL CONTINUE WITH MARGINAL
SMALL CRAFT ADVISORY CONDITIONS ALONG THE COASTAL WATERS AND ALONG
THE PAMLICO SOUND WITH WINDS 20KTG25 AND SEAS 5 TO 8 FEET. A WEAK
AREA OF LOW PRES OFF SC COAST IS RESUTING IN TIGHTER PRES GRAD EARLY
THIS MORNING...AND CONTINUED STRONGER WINDS OVER CENTRAL AND SRN
WATERS. BORDERLINE SCA WINDS OVER PAMLICO SOUNDS BUT RUC AND NAM
IDICATE PERIOD OF STRONGER WINDS PERSISTING THIS MORNING SO POSTED
SCA THERE UNTIL NOON. STONGER WINDS WILL CONTINUE OVER SRN HALF OF
WATERS INTO THIS EVENING...AND SCA SEAS WILL PERSISTING INTO SUN.
STILL SOME MODEL DIFFERENCES ON SFC LOW MOVING UP FROM SW SUN
NIGHT-MON AND LEANED TO SLIGHTLY SLOWER NAM FOR CONTINUITY. 06Z GFS
HAS COME IN LINE WITH THIS SOLUTION AS WELL. EXPECT WINDS AND SEAS
TO INCREASE LATE SUN INTO SUN NIGHT...THEN MAY HAVE WINDS BELOW 20
KT MON WITH LOW MOVING NEAR COAST. CONDITIOSN SLOWLY IMPROVING
TUE-WED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ150.
&&
$$
SYNOPSIS...RF
NEAR TERM...BTC/RF
SHORT TERM...RF
LONG TERM...RF
AVIATION...JBM/SJ
MARINE...JBM/SJ
000
FXUS62 KRAH 211510
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1010 AM EST SAT NOV 21 2009
.SYNOPSIS...
A LOW PRESSURE SYSTEM IN THE NORTHWEST GULF OF MEXICO WILL MOVE
SLOWLY NORTHEAST TOWARD THE FLORIDA GULF COAST TONIGHT...BEFORE
WEAKENING AND REFORMING ALONG THE CAROLINA COAST SUNDAY NIGHT. THIS
WILL BRING INCREASING CLOUD COVER AND A GOOD CHANCE OF RAIN TO
CENTRAL NORTH CAROLINA BY SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM SATURDAY...
15Z SFC ANALYSIS SHOWED 1025 MB HIGH PRESSURE CENTERED OVER WV. 1008
MB LOW PRESSURE WAS CENTERED NEAR BUOY 42361 IN THE NORTHWEST GULF
OF MEXICO. ALOFT...12Z RAOB ANALYSIS SHOWED AN 850 MB FRONT STALLED
OVER CENTRAL NC (LWX -1C, WAL 4C, GSO 5C, MHX 9C). FURTHER ALOFT...A
SPLIT FLOW PATTERN WAS NOTED ACROSS THE CONUS. A 500 MB LOW WAS
CENTERED OVER SOUTHEAST TX. A 90 KT SOUTHERN STREAM JET WAS NOTED
ALONG THE SOUTHERN PERIPHERY OF THE UPPER LOW OVER NORTHERN MEXICO
AND THE NORTHERN GOMEX. A 100 KT NORTHERN STREAM JET WAS NOTED OVER
THE NORTHERN MID-ATLANTIC AHEAD OF A DEAMPLIFYING NORTHERN STREAM
TROUGH OVER THE LOWER GREAT LAKES. A RIDGE ALOFT WAS PRESENT OVER
THE CENTRAL AND NORTHERN GREAT PLAINS.
TODAY:
THE UPPER LOW CURRENTLY OVER SOUTHEAST TX IS PROGGED TO MOVE ENE
INTO LA BY 00Z THIS EVENING...WHILE THE ASSOC SFC LOW CURRENTLY OVER
THE NORTHWEST GOMEX IS PROGGED TO BE LOCATED OVER OR JUST SOUTH OF
THE SOUTHERN LA COAST. SFC HIGH PRESSURE CURRENTLY CENTERED OVER WV
IS EXPECTED TO REMAIN CENTERED OVER PORTIONS OF THE MID-ATLANTIC...
LOWER GREAT LAKES AND OH VALLEY IN ASSOC/W CONFLUENT FLOW
ALOFT...WITH A SFC RIDGE AXIS EXTENDING SOUTH INTO THE CAROLINAS.
EXPECT A STEADY INFLUX OF MID/UPPER LEVEL CLOUD COVER THROUGHOUT THE
DAY TODAY AS MOISTURE MOVES DOWNSTREAM OF THE UPPER LOW ALONG THE
GULF COAST INTO THE SOUTHEAST STATES AND CAROLINAS. MOISTURE
ADVECTION WILL GENERALLY BE LIMITED TO THE UPPER LEVELS TODAY...AND
CLOUD BASES WILL REMAIN AOA 15-18 KFT...CONSISTENT WITH FCST
SOUNDINGS SHOWING ANY SATURATION AOA ~500 MB THROUGH 00Z. LIFT TODAY
ACROSS CENTRAL NC WILL BE CONFINED TO VERY WEAK LOW LEVEL
CONVERGENCE IN ASSOC/W THE STALLED 850 MB FRONT OVER THE AREA.
ALTHOUGH THERE IS CURRENTLY A NORTHERN STREAM JET ENTRANCE REGION
N/NW OF CENTRAL NC THIS MORNING...THIS FEATURE IS PROGGED TO WEAKEN
AND LIFT NORTHEAST THROUGH THE DAY. MODEL ISENTROPIC FIELDS DO
INDICATE INCREASING ISENTROPIC LIFT ACROSS THE SOUTHEAST STATES
TODAY AS A 925-850 MB WARM FRONT MOVES NORTHWARD TOWARD THE CENTRAL
GULF COAST AHEAD OF THE SFC/UPPER LOW IN LA. HOWEVER...ISENTROPIC
LIFT WILL BE WEAK AND REMAIN CONFINED WELL SOUTH/SW OF CENTRAL NC.
AS A RESULT...EXPECT NO CHANCE FOR PRECIPITATION TODAY. HIGH TEMPS
WILL BE COMPLICATED PRIMARILY BY BROKEN SKIES ASSOC/W UPPER LEVEL
CLOUD COVER. THICKNESSES WOULD ARGUE FOR HIGHS IN THE ~63F RANGE
WITH FULL SUN... HOWEVER...GIVEN WEAK LOW LEVEL NORTHEAST FLOW AND
BROKEN UPPER LEVEL CLOUD COVER...A RANGE OF 61-63F LOOKS MORE
REASONABLE...COOLEST NORTH AND WARMEST SOUTH.
TONIGHT:
THE UPPER LOW CURRENTLY OVER SOUTHEAST TX IS PROGGED TO DEAMPLIFY
TONIGHT AS IT MOVES SLOWLY ENE INTO THE DEEP SOUTH. THE ATTENDANT
SFC LOW IS ALSO PROGGED TO WEAKEN A FEW MILLIBARS AS IT MOVES ALONG
A BAROCLINIC ZONE LOCATED OVER THE CENTRAL/NORTHEAST GULF COAST.
DESPITE THE WEAKENING SOUTHERN STREAM DYNAMICS...ISENTROPIC LIFT IS
EXPECTED TO STRENGTHEN OVER THE SOUTHEAST STATES INTO THE SOUTHERN
CAROLINAS TONIGHT AS A 925-850 MB WARM FRONT LIFTS NORTHWARD INTO
AL/GA AHEAD OF THE LOW PRESSURE SYSTEM ALONG THE GULF COAST. THE
BEST LOW LEVEL MOISTURE AND ISENTROPIC LIFT IS EXPECTED TO REMAIN
WELL S/SW OF CENTRAL NC THROUGH 12Z SUN...WITH PRECIP CHANCES
LARGELY CONFINED TO AL/GA AND PERHAPS SOUTHERN/WESTERN PORTIONS OF
SC. AS A RESULT...EXPECT A DRY FORECAST TO CONTINUE THROUGH THE
OVERNIGHT HOURS. MID/UPPER LEVEL CLOUD COVER WILL BE PERVASIVE
ACROSS THE AREA TONIGHT IN ASSOC/W THE LOW PRESSURE SYSTEM UPSTREAM
OF THE AREA...AND THAT WILL BE THE PRIMARY COMPLICATING FACTOR
W/REGARD TO LOW TEMPS. A MOS GUIDANCE BLEND LOOKS PRETTY
REASONABLE...WITH LOWS IN THE LOWER/MID 40S. -VINCENT
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 315 AM...
A 700 MILLIBAR WARM FRONT NEAR THE SOUTH CAROLINA BORDER SUNRISE
SUNDAY WILL EXIT TO THE NORTH AFTER SUNSET. GIVEN THE EXPECTED
NORTHWARD PROGRESS OF THE FRONT AND MODERATE TO WEAK ISENTROPIC
LIFT NEAR 850 MILLIBARS... AT LEAST THE SOUTHWEST THREE QUARTERS
SHOULD SEE MEASURABLE RAIN BEFORE SUNSET SUNDAY.
AS THE UPPER SYSTEM LIFTS NORTHEAST THROUGH THE MOUNTAINS SUNDAY
NIGHT... LOW PRESSURE DEVELOPMENT OFF THE CAROLINAS OCCURS AND
BECOMES THE DOMINATE SURFACE LOW. GOOD MID LEVEL ISENTROPIC LIFT
IN THE MID LEVELS SHOULD KEEP RAIN CHANCES HIGH INTO SUNDAY NIGHT.
MOST MODELS DAMP OUT THE PARENT LOW PRESSURE TROUGH AS IT MOVES
NORTHEAST AND KEEP THE SURFACE LOW WEAKER THAN THE CANADIAN AS IT
APPROACHES CAPE HATTERAS. RAINFALL PERHAPS TWO TENTHS INCH
NORTHWEST TO FOUR TENTHS SOUTHEAST SUNDAY NIGHT.
WINDS WEAKEN LATE SUNDAY NIGHT INTO MONDAY AND HEAVIER
PRECIPITATION MAY MISS US TO THE EAST MONDAY. PRECIPITATION MAY
LINGER LONGEST IN THE NORTHEAST WITH THE EXITING SURFACE LOW BUT
RAINFALL AMOUNTS OF ONE TENTH INCH OR LESS EAST... AND MUCH LESS
TO THE WEST. OF COURSE IF THE LOW TRACKS CLOSER TO THE COAST...
THESE AMOUNTS ARE UNDERDONE. ONLY A SLIGHT RAIN CHANCE IN THE
NORTHEAST WITH THE EXITING LOW MONDAY NIGHT.
OVERNIGHT LOWS 45 TO 50 SUNDAY NIGHT... AND MOSTLY MID 40S TUESDAY
NIGHT. SUNDAY HIGH TEMPERATURES NEAR 50 NORTHWEST TO UPPER 50S
SOUTHEAST. IF A COLD AIR MASS DAMMING WEDGE SETS UP AS EXPECTED
MONDAY...A LOW OVERCAST WITH LIGHT RAIN OR DRIZZLE POSSIBLE. THE
CURRENT FORECAST TEN DEGREE DIURNAL RISE TO MONDAY AFTERNOON WOULD
NEED TO BE DROPPED TO THREE TO SIX DEGREES IF CLOUDS ARE ABLE TO
PERSIST INTO EARLY MONDAY EVENING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 315 AM FRIDAY...
ANY LIGHT PRECIP LINGERING INTO MONDAY NIGHT SHOULD BE GONE BY
TUESDAY MORNING...AS SOUTHWESTERLY MID LEVEL FLOW USHERS IN DRIER
AIR ABOVE THE REMAINING CAD AIRMASS. THE POSSIBILITY LINGERING LOW
CLOUDS COULD COMPLICATE THE TEMPERATURE FORECAST ON TUESDAY AS SOME
MOISTURE REMAINS BELOW A SUBSIDENCE INVERSION BENEATH DEVELOPING
SHORTWAVE RIDGING ALOFT. WILL STICK WITH MOS VALUES WITH HIGHS
64-70.
THE FORECAST GETS QUITE A BIT MORE COMPLICATED BEYOND TUESDAY...WITH
THE HANDLING OF A SHORTWAVE EXPECTED TO ENTER THE PACIFIC NORTHWEST
ON MONDAY AND EMERGE OVER THE NORTH CENTRAL PLAINS BY WED. THE
GENERAL TREND IS FOR THE DEVELOPMENT OF A HIGH AMPLITUDE LONGWAVE
TROUGH BY THE END OF THE WEEK...AND WHILE BOTH THE GFS AND ECMWF
RESOLVE SUCH A SOLUTION...THEY CURRENTLY GET THE SIMILAR ANSWER
THROUGH SOMEWHAT DIFFERENT SCENARIOS. THE GFS SENDS THE
AFOREMENTIONED SHORTWAVE ACROSS THE UPPER MIDWEST AND THE LIFTS THE
SYSTEM INTO ONTARIO BY THURSDAY...PUSHING A DRY COLD FRONT INTO
CENTRAL NC WED NIGHT. THIS IS FOLLOWED BY A SECOND SHORTWAVE THAT
DIVES SOUTH THROUGH THE MIDWEST...BUT WITH NO MORE TO WORK
WITH....POINTS EAST OF THE MOUNTAINS STAY DRY EVEN AS A SURFACE WAVE
IS INDUCED OFFSHORE THURSDAY MORNING. THE ECMWF ON THE OTHER HAND
IS MUCH SLOWER WITH THE FIRST SHORTWAVE...ALLOWING MORE MOISTURE TO
BE PULLED NORTH OVER A PERSISTENT SURFACE RIDGE ALONG THE EASTERN
SEABOARD. CYCLOGENESIS ALONG THE COAST SUBSEQUENTLY OCCURS CLOSER
TO THE COAST THURSDAY MORNING WITH LESS EASTWARD PROGRESSION OF THE
SURFACE FRONT...AND THUS THE ECMWF PRODUCES PRECIP OVER THE EASTERN
THIRD OF NC. GIVEN THESE CONTINUED MODEL INCONSISTENCIES...FEEL THE
BEST COURSE OF ACTION IS TO SHOW BELOW NORMAL TEMPS FOR THE END OF
THE WEEK...CONTINUING WITH HIGHER SLIGHT CHANCE POPS IN THE EAST
UNTIL SOME SORT OF MODEL CONVERGENCE BEGINS.
&&
.AVIATION /12Z SATURDAY THROUGH THURSDAY/...
AS OF 645 AM SATURDAY...
WITH MODELS TRENDING SLOWER ON THE ARRIVAL OF A STORM SYSTEM
CURRENTLY OVER THE WESTERN GULF COAST...VFR CONDITIONS WILL PREVAIL
THROUGH THE VALID TAF FORECAST. SCT TO BKN CIRRUS AND EVENTUALLY
CIRROSTRATUS WILL DRIFT ACROSS THE REGION TODAY AND INTO
TONIGHT...ALL AHEAD OF A STORM SYSTEM SET TO IMPACT CENTRAL NC FROM
THE SOUTHWEST DURING THE DAY SUNDAY. AT THE SURFACE...HIGH PRESSURE
TO OUR NORTH WILL SETTLE OVER NEW ENGLAND...EXTENDING A RIDGE OF DRY
AIR DOWN THE EAST COAST....AND PROVIDING A LIGHT NE WIND.
AS THE STORM SYSTEM APPROACHES FROM THE SOUTHWEST SUNDAY MORNING
CEILINGS WILL EVENTUALLY LOWER TO MVFR OR IFR LEVELS SUNDAY THROUGH
MONDAY....WITH PERIODS OF RAIN POSSIBLE AT ALL TAF SITES. AT LEAST
MVFR CEILINGS ARE EXPECTED TO PERSIST THROUGH LATE MONDAY...BEFORE A
COASTAL LOW MOVES AWAY FROM NC AND PULLS DRIER AIR INTO THE AREA.
CONDITIONS ARE EXPECTED TO REMAIN VFR FOR THE MOST THROUGH THE
BALANCE OF THE WEEK...ALTHOUGH THERE IS THE POTENTIAL FOR ANOTHER
WEATHER SYSTEM TO EFFECT MAINLY EASTERN TERMINALS BY THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...99
LONG TERM...SMITH
AVIATION...SMITH
000
FXUS62 KMHX 211442
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
915 AM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...THEN SLIDE
OFFSHORE TONIGHT. LOW PRESSURE WILL DEVELOP JUST OFFSHORE LATE
SUNDAY AND SUNDAY NIGHT...THEN LIFT NE ON MONDAY. HIGH PRESSURE
WILL REBUILD OVER THE AREA TUESDAY AND WEDNESDAY. A COLD FRONT
WILL APPROACH FROM THE WEST ON THURSDAY AND MOVE OFFSHORE
FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 2 AM SAT...LOW CLOUDS HAVE CLEARING INLAND AND N. MDLS SHOW
LOWS CLOUDS SLOWLY SLIDING S AND E AND EXPECT CLOUDS CURRENTLY
ALONG THE BEACHES WILL DIMINISH THROUGH THE MORNING. NAM FCST
SOUNDING CONT TO SHOW A NEARLY SATURATED LYR NEAR 5000 FT THIS
AFTN SO EXPECT WILL SEE DECENT AMOUNT OF STRATO-CU...WILL ALSO
HAVE SOME HIGH CLOUDS TODAY BUT EXPECT ENUF PEAKS OF SUN TO GET
HIGHS IN THE 60 TO 65 DGR RANGE.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 2 AM SAT...CLOUDS WILL THICKEN TONIGHT AS BEGIN TO SEE LOW
LVL MOISTURE INCREASE PLUS WILL HAVE SOME MID/HIGH CLOUDS WELL
AHEAD OF APPROACHING SRT WAVE. CONT PREV FCST OF SLIGHT POP LATE
TONIGHT SRN TIER. LOWS MAINLY UPR 40S TO LOWER 50S. RAIN WILL BE
INCREASING FROM SW TO NE SUNDAY AS INSENT LIFT INCREASES OVER THE
AREA AS CSTL FRONT TAKES SHAPE JUST OFFSHORE AHEAD OF APPROACHING
SRT WAVE. CONT LIKELY POPS INLAND TO CHC NE CST LATER SUNDAY. SUN
NIGHT LOOKS WET AS ISENT LIFT CONTS WITH INCREASING MID/UPR
SUPPORT WITH SRT WAVE PASSING BY TO THE NW. HAVE CATEGORICAL POPS
ALL AREAS SUN NIGHT. RAIN WILL GRAD DIMINISH FROM SW TO NE MON
HOWEVER WILL STILL HAVE GOOD CVRG EARLY AND CONT CATEGORICAL NE
CST TO LIKELY POPS ELSEWHERE WITH POPS DECREASING TO CHC LATE.
TOTAL QPF FROM THIS EVENT LOOKS TO AVG OUT IN 0.5 TO 1 INCH RANGE AND
DESPITE VERY WET GROUND MANY AREAS SHLD NOT CAUSE SIGNIFICANT
PROBLEMS. HIGHS BOTH SUN AND MON WITH CLOUDS...PRECIP AND NE WINDS
WILL BE MAINLY IN THE UPPER 50S TO LOWER 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 2 AM SAT...ANY LINGERING LIGHT RAIN/DRIZZLE WILL END MON
NIGHT. WITH HIGH PRES BUILDING IN TUE AND WED EXPECT DRY
CONDITIONS. IMPRESSIVE SRT WAVE/COLD FRONT WILL APPROACH THU AND
MOVE OFFSHORE FRI. MDLS DIFFER WITH GFS SHOWING LIMITED MOISTURE
AND BULK OF PRECIP OFFSHORE. EMCWF IS WETTER...ESPCLY CST WITH
MOISTURE COMING IN OFF ATLC. CURRENTLY HAVE CHC POPS THU AND WILL
NOT CHANGE UNTIL GET MORE CLARITY FROM MDLS. COOLER AND DRY FRI IN
WAKE OF FRONT/SRT WAVE.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
AS OF 915 AM...A MIX OF LAYERED CLOUDS EXPECTED FOR THE REMAINDER OF
THE DAY WITH VFR CEILINGS. TONIGHT...HIGHER CLOUDS WILL SINK INTO A
MID DECK WHICH ALONG WITH LIGHT WINDS WILL HELP INHIBIT FOG DESPITE
HIGHER DEWPOINTS.
LOW PRES MOVING UP FROM SW WILL PRODUCE DETERIORATING CONDITIONS
LATE SUN...WITH WDSPRD IFR SUN NIGHT AND MON. LOWER CIGS LIKELY TO
PERSIST INTO TUE DUE TO WEDGE CONDITIONS IN WAKE OF DEPARTED LOW
PRES.
&&
.MARINE...
AS OF 915 AM...WE WILL CONTINUE WITH MARGINAL
SMALL CRAFT ADVISORY CONDITIONS ALONG THE COASTAL WATERS AND ALONG
THE PAMLICO SOUND WITH WINDS 20KTG25 AND SEAS 5 TO 8 FEET. A WEAK
AREA OF LOW PRES OFF SC COAST IS RESUTING IN TIGHTER PRES GRAD EARLY
THIS MORNING...AND CONTINUED STRONGER WINDS OVER CENTRAL AND SRN
WATERS. BORDERLINE SCA WINDS OVER PAMLICO SOUNDS BUT RUC AND NAM
IDICATE PERIOD OF STRONGER WINDS PERSISTING THIS MORNING SO POSTED
SCA THERE UNTIL NOON. STONGER WINDS WILL CONTINUE OVER SRN HALF OF
WATERS INTO THIS EVENING...AND SCA SEAS WILL PERSISTING INTO SUN.
STILL SOME MODEL DIFFERENCES ON SFC LOW MOVING UP FROM SW SUN
NIGHT-MON AND LEANED TO SLIGHTLY SLOWER NAM FOR CONTINUITY. 06Z GFS
HAS COME IN LINE WITH THIS SOLUTION AS WELL. EXPECT WINDS AND SEAS
TO INCREASE LATE SUN INTO SUN NIGHT...THEN MAY HAVE WINDS BELOW 20
KT MON WITH LOW MOVING NEAR COAST. CONDITIOSN SLOWLY IMPROVING
TUE-WED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ150.
&&
$$
SYNOPSIS...RF
NEAR TERM...RF
SHORT TERM...RF
LONG TERM...RF
AVIATION...JBM/SJ
MARINE...JBM/SJ
000
FXUS62 KILM 211314
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
814 AM EST SAT NOV 21 2009
.SYNOPSIS...
INCREASING MOISTURE FROM THE GULF OF MEXICO WILL ENTER THE CAROLINAS
SUNDAY INTO MONDAY WITH WIDESPREAD RAIN EXPECTED. A BRIEF WARMUP IS
EXPECTED TUESDAY AND WEDNESDAY. A STRONG COLD FRONT THURSDAY WILL
USHER IN SOME COLDER AIR FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 9 AM SATURDAY...PERIODS OF MULTI-LAYERED CLOUDS WILL KEEP
SKIES VARIABLY CLOUDY TODAY WITH A COOL NORTHEAST BREEZE IN PLACE.
LOW PRESSURE DEVELOPED OVERNIGHT ALONG A NEARLY STATIONARY FRONT
WELL OFFSHORE. THIS LED TO AN ENHANCEMENT IN THE LOW-LEVEL NORTHEAST
FLOW OVERNIGHT. THIS LOW WILL MOVE NORTHEAST AND AWAY FROM THE AREA
THIS AFTERNOON...BUT NEW LOW PRESSURE WILL DEVELOP LATE TONIGHT
ALONG THE EASTERN GULF COAST.
IT APPEARS ENOUGH DRY AIR WILL REMAIN ENTRENCHED IN THE SUB-CLOUD
LAYER TO PREVENT MEASURABLE PRECIPITATION FROM DEVELOPING ACROSS OUR
AREA THROUGH DAYBREAK SUNDAY. THIS IS IN AGREEMENT WITH THE PREVIOUS
FORECAST AND ALSO THE 06Z RUNS OF THE NAM AND GFS. THE 06Z NAM WAS
NOTABLE IN ITS DEPICTION OF A VERY DEEP DRY SUB-CLOUD LAYER MOVING
IN LATE TONIGHT WHICH COULD ACTUALLY DELAY THE ONSET OF
PRECIPITATION WELL INTO THE DAY SUNDAY. WE WILL REVISIT THIS
POTENTIAL WITH THE AFTERNOON FORECAST UPDATE.
THE INCOMING AIRMASS IS QUITE CHILLY AND EVEN WITH FILTERED SUNSHINE
WE WILL ONLY REACH THE LOWER TO MID 60S THIS AFTERNOON. THE PREVIOUS
FORECAST REMAINS IN GREAT SHAPE AND NO SIGNIFICANT CHANGES WERE
NEEDED.
&&
.SHORT TERM/SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...
MOISTURE OVERRUNNING NORTHEASTERLY SURFACE FLOW ASSOCIATED WITH
WEDGE OF HIGH PRESSURE WILL BRING PLENTY OF CLOUDINESS TO START THE
PERIOD. INCREASING ISENTROPIC UPGLIDE WILL ALSO RAMP UP RAIN
CHANCES...ENDING UP IN THE CATEGORICAL RANGE BY EVENING. QPF
FORECAST IS STILL A LITTLE UNCERTAIN AS GUIDANCE HAS REALLY BACKED
OFF WITH RAINFALL WHEN COMPARED TO PREVIOUS DAYS. RAIN CHANCES
REMAIN FAIRLY HIGH SUNDAY NIGHT AS THE WEAKENING LOW JUMPS TO THE
EASTERN SIDE OF THE WEDGE AND ENDS UP OFFSHORE. SOON THEREAFTER RAIN
CHANCES SHOULD TAPER OFF FROM WEST TO EAST EARLY MONDAY. CLOUDS AND
POSSIBLY DRIZZLE COULD LINGER INTO THE MORNING HOURS. MIGHT EVEN SEE
A TREND TOWARDS OVERALL SLOWER PROGRESSION WHICH COULD MEAN DRIZZLE
AND CLOUDS LINGER MOST OF THE DAY. HAVE UNDERCUT GUIDANCE ON MONDAY
HIGH TEMPS.
&&
.LONG TERM/TUESDAY THROUGH FRIDAY/...
AS OF 3 PM SATURDAY...
A WEAK UPPER RIDGE MANAGES TO BUILD ON TUESDAY AND THIS SHOULD BRING
A MILD AFTERNOON. WEDNESDAY MAY ALSO BRING HIGHS IN THE LOW 70S
AHEAD OF WHAT WILL END UP BEING A PRETTY STRONG COLD FRONT ON
THURSDAY. LITTLE TO NO MOISTURE FLOW AHEAD OF THE FRONT SO ITS
PASSAGE SHOULD BE DRY. THE ECWMF HAS INDICATED OTHERWISE FOR A FEW
RUNS NOW BUT THIS MODEL HAS BEEN DISPLAYING A VERY WET BIAS FOR SOME
TIME LOCALLY IN SUCH SETUPS. DRY AND COOL WEATHER FOR THE REST OF
THE PD WITH HIGHS STRUGGLING TO LOW 60S BY DAY AND UPPER 30S AT
NIGHT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
WEAK LOW PRESSURE WILL MOVE ALONG A STALLED BOUNDARY JUST OFFSHORE
TODAY BRINGING MID LEVEL CLOUD COVER TO THE COASTAL TERMINALS. A
MORE SIGNIFICANT SYSTEM DEVELOPING IN THE GULF OF MEXICO WILL CAUSE
GRADUALLY THICKENING HIGH CLOUDS AT ALL TERMINALS THROUGH THE PERIOD.
4SM VSBY AT LBT IS ONLY RESTRICTION THIS MORNING...AND THIS WILL
BURN OFF QUICKLY AFTER SUNRISE LEAVING VFR ALL TERMINALS. 11U-3.9U
MICRON SATELLITE IS BUSY...WITH HIGH LEVEL CI STREAMING ACROSS TO
THE NE AND MVFR/VFR STRATUS JUST OFFSHORE. WITH A MODERATE NE WIND
TODAY AT AROUND 10 KT...EXPECT SOME OF THIS STRATUS TO OCCASIONALLY
MOVE ONSHORE CREATING 5K FOOT CIGS AT ILM/CRE/MYR. DO NOT BELIEVE
ANY OF THIS WILL GET TO FLO/LBT...BUT SOME AFTN CU MAY DEVELOP AT
THOSE TERMINALS AROUND 4K FEET. THIS CU WILL HAVE VERY LIMITED
VERTICAL EXTENT DUE TO THE DRY MID LEVELS OF THE COLUMN. MODEL
GUIDANCE HAS SLOWED IN ITS PROGRESSION OF THE GULF OF MEXICO
SYSTEM...AND HAVE REMOVED ANY VCSH TO REFLECT THIS MORE DELAYED
SOLUTION. VFR WILL BE THE RULE ALL DAY WITH HIGH LEVEL CI LOWERING
TO AN AS/AC DECK AROUND 12K FEET BY THE END OF THE TAF PERIOD AS THE
COLUMN SATURATES FROM THE TOP DOWN.
EXTENDED OUTLOOK...POTENTIAL IFR DUE TO SHOWERS AND LOW CEILINGS
SUNDAY AND MONDAY. FOG POSSIBLE TUESDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 8 AM SATURDAY...LOW PRESSURE WELL OFF THE SOUTH CAROLINA COAST
AND HIGH PRESSURE OVER THE GREAT LAKES ARE SETTING THE STAGE FOR A
SUSTAINED PERIOD OF NORTHEAST WINDS LASTING THROUGH THE NEXT SEVERAL
DAYS. A PINCHED GRADIENT DEVELOPED OVERNIGHT WITH WIND GUSTS UP TO
30 KNOTS AT THE NEARSHORE WRIGHTSVILLE BEACH BUOY. WINDS HAVE
DIMINISHED A LITTLE AND WE SHOULD DROP TO A RELATIVE LULL IN WIND
SPEEDS THIS AFTERNOON. LOW PRESSURE TONIGHT WILL DEVELOP ALONG THE
EASTERN GULF COAST WHICH WILL LEAD TO AN ENHANCEMENT OF THE LOCAL
PRESSURE GRADIENT LATE TONIGHT.
SEAS ARE STILL RUNNING 7 FT AT THE FRYING PAN SHOALS BUOY...AND 5 FT
AT THE NEARSHORE WRIGHTSVILLE BEACH BUOY. THIS MATCHES VERY WELL
WITH THE LOCAL SWAN WAVE MODEL AND NO SIGNIFICANT CHANGES ARE NEEDED
TO THE PREVIOUS FORECAST.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...
SURFACE HIGH PRESSURE WEDGE IN CONTROL ON SUNDAY TO BRING A MODERATE
GRADIENT WIND. SMALL CRAFT ADVISORY FROM NEAR TERM HAS BEEN EXTENDED
THROUGH SUNDAY FOR NORTHERN TWO ZONES AS 6 FT SEAS AFFECT THE OUTER
REACHES ALONG FRYING PAN SHOALS. WAVE SHADOWING WILL PROBABLY
PRECLUDE THIS OVER SOUTHERN WATERS. A FLAT WAVE OF LOW PRESSURE WILL
RIDE UP THE EAST SIDE OF THE WEDGE SUNDAY NIGHT INTO MONDAY. THIS
WILL SLIGHTLY TAPER THE GRADIENT AND COULD LOWER THE SEAS ENOUGH TO
DROP ANY ADVISORIES. WEDGE WEAKENS BUT REMAINS IN PLACE FOR THE
REMAINDER OF MONDAY AND MONDAY NIGHT KEEPING WINDS WITH A NORTHERLY
COMPONENT.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 PM SATURDAY...
LOOKS LIKE A FAIRLY QUIET PATTERN FOR MOST OF THE PERIOD. HIGH
PRESSURE REMAINS TO THE NORTH TUESDAY BRINGING A LIGHT NORTHERLY
WIND AND SEAS IN THE 2 TO 3 FT RANGE. CHANGES MAY BE UNDERWAY COME
WEDNESDAY AS THE HIGH BEGINS TO LIFT OUT AHEAD OF AN APPROACHING
COLD FRONT. THE TIMING OF THIS FRONT AND THE EVOLUTION OF SURFACE
FEATURES ASSOCIATED WITH IT IS HIGHLY UNCERTAIN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR AMZ256.
SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...MBB/TRA
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...JDW
000
FXUS62 KRAH 211147
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
645 AM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE TO OUR NORTH WILL BRING NORTHEAST FLOW TO NORTH
CAROLINA INTO SUNDAY. THE NEXT STORM SYSTEM WILL MOVE INTO THE
REGION FROM THE SOUTHWEST AND BRING CLOUDS AND RAIN FOR SUNDAY AND
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM...
SURFACE HIGH PRESSURE NORTH OF NORTH CAROLINA WILL KEEP NORTHEAST
FLOW OVER CENTRAL NORTH CAROLINA INTO TONIGHT. EXPECTING ENOUGH
SUNSHINE THROUGH THE MID AND HIGH CLOUDS TO BRING TEMPERATURES TO
JUST SHORT OF FULL SUN VALUES FOR NORTHEAST FLOW. AFTERNOON HIGHS
UPPER 50S TO LOWER 60S NORTH... AND 62 TO 65 SOUTH.
AN UPPER LEVEL SYSTEM DROPPING INTO TEXAS IS GENERATING SURFACE
LOW PRESSURE IN THE NORTHWEST GULF OF MEXICO AT THIS TIME. BOTH
THESE LOWS FORECAST TO ROUGHLY MOVE EAST NORTHEAST INTO SUNDAY.
THE NAM 700 MILLIBAR PRESSURE FIELD IS PERHAPS TOO WEAK AND PREFER
THE STRONGER MID LEVEL FRONT OF THE CANADIAN AND GFS MODELS. THE
GFS AND CANADIAN DEPICT A 700 MILLIBAR WARM FRONT... BARELY
LIFTING NORTH INTO NORTH CAROLINA BY SUNRISE SUNDAY. ISENTROPIC
LIFT IS QUITE WEAK BELOW THIS FRONT SO ANY RAINFALL SHOULD BE
LATE... WELL UNDER ONE TENTH INCH AND NOT STRAY TOO FAR NORTH BY
SUNRISE. INCREASED LOWER CLOUDINESS AND MORE OF A BREEZE THAN
FRIDAY NIGHT SHOULD YIELD LOW TEMPERATURES IN THE MID TO UPPER
40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 315 AM...
A 700 MILLIBAR WARM FRONT NEAR THE SOUTH CAROLINA BORDER SUNRISE
SUNDAY WILL EXIT TO THE NORTH AFTER SUNSET. GIVEN THE EXPECTED
NORTHWARD PROGRESS OF THE FRONT AND MODERATE TO WEAK ISENTROPIC
LIFT NEAR 850 MILLIBARS... AT LEAST THE SOUTHWEST THREE QUARTERS
SHOULD SEE MEASURABLE RAIN BEFORE SUNSET SUNDAY.
AS THE UPPER SYSTEM LIFTS NORTHEAST THROUGH THE MOUNTAINS SUNDAY
NIGHT... LOW PRESSURE DEVELOPMENT OFF THE CAROLINAS OCCURS AND
BECOMES THE DOMINATE SURFACE LOW. GOOD MID LEVEL ISENTROPIC LIFT
IN THE MID LEVELS SHOULD KEEP RAIN CHANCES HIGH INTO SUNDAY NIGHT.
MOST MODELS DAMP OUT THE PARENT LOW PRESSURE TROUGH AS IT MOVES
NORTHEAST AND KEEP THE SURFACE LOW WEAKER THAN THE CANADIAN AS IT
APPROACHES CAPE HATTERAS. RAINFALL PERHAPS TWO TENTHS INCH
NORTHWEST TO FOUR TENTHS SOUTHEAST SUNDAY NIGHT.
WINDS WEAKEN LATE SUNDAY NIGHT INTO MONDAY AND HEAVIER
PRECIPITATION MAY MISS US TO THE EAST MONDAY. PRECIPITATION MAY
LINGER LONGEST IN THE NORTHEAST WITH THE EXITING SURFACE LOW BUT
RAINFALL AMOUNTS OF ONE TENTH INCH OR LESS EAST... AND MUCH LESS
TO THE WEST. OF COURSE IF THE LOW TRACKS CLOSER TO THE COAST...
THESE AMOUNTS ARE UNDERDONE. ONLY A SLIGHT RAIN CHANCE IN THE
NORTHEAST WITH THE EXITING LOW MONDAY NIGHT.
OVERNIGHT LOWS 45 TO 50 SUNDAY NIGHT... AND MOSTLY MID 40S TUESDAY
NIGHT. SUNDAY HIGH TEMPERATURES NEAR 50 NORTHWEST TO UPPER 50S
SOUTHEAST. IF A COLD AIR MASS DAMMING WEDGE SETS UP AS EXPECTED
MONDAY...A LOW OVERCAST WITH LIGHT RAIN OR DRIZZLE POSSIBLE. THE
CURRENT FORECAST TEN DEGREE DIURNAL RISE TO MONDAY AFTERNOON WOULD
NEED TO BE DROPPED TO THREE TO SIX DEGREES IF CLOUDS ARE ABLE TO
PERSIST INTO EARLY MONDAY EVENING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 315 AM FRIDAY...
ANY LIGHT PRECIP LINGERING INTO MONDAY NIGHT SHOULD BE GONE BY
TUESDAY MORNING...AS SOUTHWESTERLY MID LEVEL FLOW USHERS IN DRIER
AIR ABOVE THE REMAINING CAD AIRMASS. THE POSSIBILITY LINGERING LOW
CLOUDS COULD COMPLICATE THE TEMPERATURE FORECAST ON TUESDAY AS SOME
MOISTURE REMAINS BELOW A SUBSIDENCE INVERSION BENEATH DEVELOPING
SHORTWAVE RIDGING ALOFT. WILL STICK WITH MOS VALUES WITH HIGHS
64-70.
THE FORECAST GETS QUITE A BIT MORE COMPLICATED BEYOND TUESDAY...WITH
THE HANDLING OF A SHORTWAVE EXPECTED TO ENTER THE PACIFIC NORTHWEST
ON MONDAY AND EMERGE OVER THE NORTH CENTRAL PLAINS BY WED. THE
GENERAL TREND IS FOR THE DEVELOPMENT OF A HIGH AMPLITUDE LONGWAVE
TROUGH BY THE END OF THE WEEK...AND WHILE BOTH THE GFS AND ECMWF
RESOLVE SUCH A SOLUTION...THEY CURRENTLY GET THE SIMILAR ANSWER
THROUGH SOMEWHAT DIFFERENT SCENARIOS. THE GFS SENDS THE
AFOREMENTIONED SHORTWAVE ACROSS THE UPPER MIDWEST AND THE LIFTS THE
SYSTEM INTO ONTARIO BY THURSDAY...PUSHING A DRY COLD FRONT INTO
CENTRAL NC WED NIGHT. THIS IS FOLLOWED BY A SECOND SHORTWAVE THAT
DIVES SOUTH THROUGH THE MIDWEST...BUT WITH NO MORE TO WORK
WITH....POINTS EAST OF THE MOUNTAINS STAY DRY EVEN AS A SURFACE WAVE
IS INDUCED OFFSHORE THURSDAY MORNING. THE ECMWF ON THE OTHER HAND
IS MUCH SLOWER WITH THE FIRST SHORTWAVE...ALLOWING MORE MOISTURE TO
BE PULLED NORTH OVER A PERSISTENT SURFACE RIDGE ALONG THE EASTERN
SEABOARD. CYCLOGENESIS ALONG THE COAST SUBSEQUENTLY OCCURS CLOSER
TO THE COAST THURSDAY MORNING WITH LESS EASTWARD PROGRESSION OF THE
SURFACE FRONT...AND THUS THE ECMWF PRODUCES PRECIP OVER THE EASTERN
THIRD OF NC. GIVEN THESE CONTINUED MODEL INCONSISTENCIES...FEEL THE
BEST COURSE OF ACTION IS TO SHOW BELOW NORMAL TEMPS FOR THE END OF
THE WEEK...CONTINUING WITH HIGHER SLIGHT CHANCE POPS IN THE EAST
UNTIL SOME SORT OF MODEL CONVERGENCE BEGINS.
&&
.AVIATION /12Z SATURDAY THROUGH THURSDAY/...
AS OF 645 AM SATURDAY...
WITH MODELS TRENDING SLOWER ON THE ARRIVAL OF A STORM SYSTEM
CURRENTLY OVER THE WESTERN GULF COAST...VFR CONDITIONS WILL PREVAIL
THROUGH THE VALID TAF FORECAST. SCT TO BKN CIRRUS AND EVENTUALLY
CIRROSTRATUS WILL DRIFT ACROSS THE REGION TODAY AND INTO
TONIGHT...ALL AHEAD OF A STORM SYSTEM SET TO IMPACT CENTRAL NC FROM
THE SOUTHWEST DURING THE DAY SUNDAY. AT THE SURFACE...HIGH PRESSURE
TO OUR NORTH WILL SETTLE OVER NEW ENGLAND...EXTENDING A RIDGE OF DRY
AIR DOWN THE EAST COAST....AND PROVIDING A LIGHT NE WIND.
AS THE STORM SYSTEM APPROACHES FROM THE SOUTHWEST SUNDAY MORNING
CEILINGS WILL EVENTUALLY LOWER TO MVFR OR IFR LEVELS SUNDAY THROUGH
MONDAY....WITH PERIODS OF RAIN POSSIBLE AT ALL TAF SITES. AT LEAST
MVFR CEILINGS ARE EXPECTED TO PERSIST THROUGH LATE MONDAY...BEFORE A
COASTAL LOW MOVES AWAY FROM NC AND PULLS DRIER AIR INTO THE AREA.
CONDITIONS ARE EXPECTED TO REMAIN VFR FOR THE MOST THROUGH THE
BALANCE OF THE WEEK...ALTHOUGH THERE IS THE POTENTIAL FOR ANOTHER
WEATHER SYSTEM TO EFFECT MAINLY EASTERN TERMINALS BY THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
LONG TERM...SMITH
AVIATION...SMITH
000
FXUS62 KILM 211141
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
636 AM EST SAT NOV 21 2009
.SYNOPSIS...
GULF OF MEXICO MOISTURE WILL OVERRUN A WEDGE OF HIGH PRESSURE THROUGH
SUNDAY. A BRIEF WARMUP IS EXPECTED TUESDAY AND WEDNESDAY. A STRONG
COLD FRONT THURSDAY WILL USHER IN SOME COLDER AIR FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...WEAK WAVE OF LOW PRESSURE WILL MOVE NE THIS
MORNING ALONG A STALLED FRONT LOCATED ACROSS THE OFFSHORE WATERS.
THIS WILL KEEP THICKEST CLOUD COVER ALONG THE COAST. A BROAD AREA OF
HIGH PRESSURE CENTERED ACROSS THE OHIO VALLEY WILL MOVE TO NEW
ENGLAND AND QUEBEC PROVINCE. THIS AREA OF HIGH PRESSURE WILL BEGIN
TO WEDGE ACROSS THE CAROLINAS THIS PERIOD. THIS WILL SET THE STAGE
FOR INCREASING ISENTROPIC UPGLIDE...MAINLY LATE IN THE PERIOD.
AT THIS TIME...IT LOOKS LIKE ALTHOUGH CLOUDS WILL BE PLENTIFUL THIS
PERIOD...AND THICKEST ALONG THE COAST...RAINFALL WILL BE SLOW TO
DEVELOP GIVEN THE DRYNESS OF THE COLUMN BELOW 4 KFT. HOWEVER...WE DO
EXPECT LIGHT RAIN TO BEGIN TO MOVE IN FROM THE SW/DEVELOP ACROSS THE
AREA BY DAYBREAK ON SUN AS COLUMN SATURATES FROM THE TOP DOWN.
WEAK WAVE OF LOW PRESSURE OFFSHORE WILL AID IN REINFORCING COOL NE
FLOW ACROSS THE AREA. COUPLE THIS WITH CLOUDS AND WE EXPECT MAXIMUMS
THIS PERIOD WILL BE HELD TO THE COOLER SIDE OF MODEL CONSENSUS.
COOLEST TEMPS SHOULD BE ACROSS THE CAPE FEAR REGION...BUT STILL ALL
AREAS SHOULD BE AT OR JUST A DEGREE OR TWO BELOW NORMAL. TONIGHT...
AS WEDGE INTENSIFIES ACROSS THE AREA...AND WITH COOL NE FLOW
CONTINUING...TEMPS SHOULD AGAIN BE DOWN IN THE MID 40S TO NEAR 50
DEGREES.
&&
.SHORT TERM/SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...
MOISTURE OVERRUNNING NORTHEASTERLY SURFACE FLOW ASSOCIATED WITH
WEDGE OF HIGH PRESSURE WILL BRING PLENTY OF CLOUDINESS TO START THE
PERIOD. INCREASING ISENTROPIC UPGLIDE WILL ALSO RAMP UP RAIN
CHANCES...ENDING UP IN THE CATEGORICAL RANGE BY EVENING. QPF
FORECAST IS STILL A LITTLE UNCERTAIN AS GUIDANCE HAS REALLY BACKED
OFF WITH RAINFALL WHEN COMPARED TO PREVIOUS DAYS. RAIN CHANCES
REMAIN FAIRLY HIGH SUNDAY NIGHT AS THE WEAKENING LOW JUMPS TO THE
EASTERN SIDE OF THE WEDGE AND ENDS UP OFFSHORE. SOON THEREAFTER RAIN
CHANCES SHOULD TAPER OFF FROM WEST TO EAST EARLY MONDAY. CLOUDS AND
POSSIBLY DRIZZLE COULD LINGER INTO THE MORNING HOURS. MIGHT EVEN SEE
A TREND TOWARDS OVERALL SLOWER PROGRESSION WHICH COULD MEAN DRIZZLE
AND CLOUDS LINGER MOST OF THE DAY. HAVE UNDERCUT GUIDANCE ON MONDAY
HIGH TEMPS.
&&
.LONG TERM/TUESDAY THROUGH FRIDAY/...
AS OF 3 PM SATURDAY...
A WEAK UPPER RIDGE MANAGES TO BUILD ON TUESDAY AND THIS SHOULD BRING
A MILD AFTERNOON. WEDNESDAY MAY ALSO BRING HIGHS IN THE LOW 70S
AHEAD OF WHAT WILL END UP BEING A PRETTY STRONG COLD FRONT ON
THURSDAY. LITTLE TO NO MOISTURE FLOW AHEAD OF THE FRONT SO ITS
PASSAGE SHOULD BE DRY. THE ECWMF HAS INDICATED OTHERWISE FOR A FEW
RUNS NOW BUT THIS MODEL HAS BEEN DISPLAYING A VERY WET BIAS FOR SOME
TIME LOCALLY IN SUCH SETUPS. DRY AND COOL WEATHER FOR THE REST OF
THE PD WITH HIGHS STRUGGLING TO LOW 60S BY DAY AND UPPER 30S AT
NIGHT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
WEAK LOW PRESSURE WILL MOVE ALONG A STALLED BOUNDARY JUST OFFSHORE
TODAY BRINGING MID LEVEL CLOUD COVER TO THE COASTAL TERMINALS. A
MORE SIGNIFICANT SYSTEM DEVELOPING IN THE GULF OF MEXICO WILL CAUSE
GRADUALLY THICKENING HIGH CLOUDS AT ALL TERMINALS THROUGH THE PERIOD.
4SM VSBY AT LBT IS ONLY RESTRICTION THIS MORNING...AND THIS WILL
BURN OFF QUICKLY AFTER SUNRISE LEAVING VFR ALL TERMINALS. 11U-3.9U
MICRON SATELLITE IS BUSY...WITH HIGH LEVEL CI STREAMING ACROSS TO
THE NE AND MVFR/VFR STRATUS JUST OFFSHORE. WITH A MODERATE NE WIND
TODAY AT AROUND 10 KT...EXPECT SOME OF THIS STRATUS TO OCCASIONALLY
MOVE ONSHORE CREATING 5K FOOT CIGS AT ILM/CRE/MYR. DO NOT BELIEVE
ANY OF THIS WILL GET TO FLO/LBT...BUT SOME AFTN CU MAY DEVELOP AT
THOSE TERMINALS AROUND 4K FEET. THIS CU WILL HAVE VERY LIMITED
VERTICAL EXTENT DUE TO THE DRY MID LEVELS OF THE COLUMN. MODEL
GUIDANCE HAS SLOWED IN ITS PROGRESSION OF THE GULF OF MEXICO
SYSTEM...AND HAVE REMOVED ANY VCSH TO REFLECT THIS MORE DELAYED
SOLUTION. VFR WILL BE THE RULE ALL DAY WITH HIGH LEVEL CI LOWERING
TO AN AS/AC DECK AROUND 12K FEET BY THE END OF THE TAF PERIOD AS THE
COLUMN SATURATES FROM THE TOP DOWN.
EXTENDED OUTLOOK...POTENTIAL IFR DUE TO SHOWERS AND LOW CEILINGS
SUNDAY AND MONDAY. FOG POSSIBLE TUESDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...WILL HOIST A SMALL CRAFT ADVISORY FOR ALL
ZONES EXCEPT AMZ254 WHERE A SMALL CRAFT SHOULD EXERCISE CAUTION
HEADLINE WILL REMAIN IN PLACE. PINCHED GRADIENT HAS DEVELOPED ACROSS
THE WATERS EARLY THIS MORNING...THE RESULT OF PRESSURE DIFFERENCES
BETWEEN WEAK LOW PRESSURE MOVING NE ALONG A STALLED FRONT OFFSHORE
OF THE CAROLINAS AND HIGH PRESSURE CENTERED ACROSS THE OHIO VALLEY.
THIS PINCHED GRADIENT SHOULD RELAX LATER IN THE DAY AS WEAK WAVE OF
LOW PRESSURE MOVES FURTHER AWAY. GRADIENT WILL TIGHTEN UP AGAIN THIS
EVE AND ESPECIALLY OVERNIGHT AS WEDGE OF HIGH PRESSURE INTENSIFIES
ACROSS THE AREA WHILE LOW PRESSURE REACHES THE NORTHEASTERN GULF
COAST. PERSISTENT NE WINDS WILL REACH MARGINAL SMALL CRAFT ADVISORY
LEVELS ACROSS THE MAJORITY OF THE AREA. SEAS WILL NOT CHANGE MUCH
THROUGH THE PERIOD...AND WILL BE AS HIGH AS 5 TO 7 FT ACROSS THE
OUTER WATERS. NEAR SHORE SEAS WILL BE LOWER IN AREAS WHERE FETCH IS
GREATLY REDUCED IN NE FLOW.
SHORT TERM/SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...
SURFACE HIGH PRESSURE WEDGE IN CONTROL ON SUNDAY TO BRING A MODERATE
GRADIENT WIND. SMALL CRAFT ADVISORY FROM NEAR TERM HAS BEEN EXTENDED
THROUGH SUNDAY FOR NORTHERN TWO ZONES AS 6 FT SEAS AFFECT THE OUTER
REACHES ALONG FRYING PAN SHOALS. WAVE SHADOWING WILL PROBABLY
PRECLUDE THIS OVER SOUTHERN WATERS. A FLAT WAVE OF LOW PRESSURE WILL
RIDE UP THE EAST SIDE OF THE WEDGE SUNDAY NIGHT INTO MONDAY. THIS
WILL SLIGHTLY TAPER THE GRADIENT AND COULD LOWER THE SEAS ENOUGH TO
DROP ANY ADVISORIES. WEDGE WEAKENS BUT REMAINS IN PLACE FOR THE
REMAINDER OF MONDAY AND MONDAY NIGHT KEEPING WINDS WITH A NORTHERLY
COMPONENT.
&&
LONG TERM/TUESDAY THROUGH WEDNESDAY/...
AS OF 3 PM SATURDAY...
LOOKS LIKE A FAIRLY QUIET PATTERN FOR MOST OF THE PERIOD. HIGH
PRESSURE REMAINS TO THE NORTH TUESDAY BRINGING A LIGHT NORTHERLY
WIND AND SEAS IN THE 2 TO 3 FT RANGE. CHANGES MAY BE UNDERWAY COME
WEDNESDAY AS THE HIGH BEGINS TO LIFT OUT AHEAD OF AN APPROACHING
COLD FRONT. THE TIMING OF THIS FRONT AND THE EVOLUTION OF SURFACE
FEATURES ASSOCIATED WITH IT IS HIGHLY UNCERTAIN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR AMZ256.
SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...MBB
NEAR TERM...RJD
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...JDW
000
FXUS62 KILM 211136
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
636 AM EST SAT NOV 21 2009
.SYNOPSIS...
GULF OF MEXICO MOISTURE WILL OVERRUN A WEDGE OF HIGH PRESSURE THROUGH
SUNDAY. A BRIEF WARMUP IS EXPECTED TUESDAY AND WEDNESDAY. A STRONG
COLD FRONT THURSDAY WILL USHER IN SOME COLDER AIR FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...WEAK WAVE OF LOW PRESSURE WILL MOVE NE THIS
MORNING ALONG A STALLED FRONT LOCATED ACROSS THE OFFSHORE WATERS.
THIS WILL KEEP THICKEST CLOUD COVER ALONG THE COAST. A BROAD AREA OF
HIGH PRESSURE CENTERED ACROSS THE OHIO VALLEY WILL MOVE TO NEW
ENGLAND AND QUEBEC PROVINCE. THIS AREA OF HIGH PRESSURE WILL BEGIN
TO WEDGE ACROSS THE CAROLINAS THIS PERIOD. THIS WILL SET THE STAGE
FOR INCREASING ISENTROPIC UPGLIDE...MAINLY LATE IN THE PERIOD.
AT THIS TIME...IT LOOKS LIKE ALTHOUGH CLOUDS WILL BE PLENTIFUL THIS
PERIOD...AND THICKEST ALONG THE COAST...RAINFALL WILL BE SLOW TO
DEVELOP GIVEN THE DRYNESS IN THE COLUMN BELOW 4 KFT. HOWEVER...WE DO
EXPECT LIGHT RAIN TO BEGIN TO MOVE IN FROM THE SW/DEVELOP ACROSS THE
AREA BY DAYBREAK ON SUN AS COLUMN SATURATES FROM THE TOP DOWN.
WEAK WAVE OF LOW PRESSURE OFFSHORE WILL AID IN REINFORCING COOL NE
FLOW ACROSS THE AREA. COUPLE THIS WITH CLOUDS AND WE EXPECT MAXIMUMS
THIS PERIOD WILL BE HELD TO THE COOLER SIDE OF MODEL CONSENSUS.
COOLEST TEMPS SHOULD BE ACROSS THE CAPE FEAR REGION...BUT STILL ALL
AREAS SHOULD BE AT OR JUST A DEGREE OR TWO BELOW NORMAL. TONIGHT...
AS WEDGE INTENSIFIES ACROSS THE AREA...AND WITH COOL NE FLOW
CONTINUING...TEMPS SHOULD AGAIN BE DOWN IN THE MID 40S TO NEAR 50
DEGREES.
&&
.SHORT TERM/SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...
MOISTURE OVERRUNNING NORTHEASTERLY SURFACE FLOW ASSOCIATED WITH
WEDGE OF HIGH PRESSURE WILL BRING PLENTY OF CLOUDINESS TO START THE
PERIOD. INCREASING ISENTROPIC UPGLIDE WILL ALSO RAMP UP RAIN
CHANCES...ENDING UP IN THE CATEGORICAL RANGE BY EVENING. QPF
FORECAST IS STILL A LITTLE UNCERTAIN AS GUIDANCE HAS REALLY BACKED
OFF WITH RAINFALL WHEN COMPARED TO PREVIOUS DAYS. RAIN CHANCES
REMAIN FAIRLY HIGH SUNDAY NIGHT AS THE WEAKENING LOW JUMPS TO THE
EASTERN SIDE OF THE WEDGE AND ENDS UP OFFSHORE. SOON THEREAFTER RAIN
CHANCES SHOULD TAPER OFF FROM WEST TO EAST EARLY MONDAY. CLOUDS AND
POSSIBLY DRIZZLE COULD LINGER INTO THE MORNING HOURS. MIGHT EVEN SEE
A TREND TOWARDS OVERALL SLOWER PROGRESSION WHICH COULD MEAN DRIZZLE
AND CLOUDS LINGER MOST OF THE DAY. HAVE UNDERCUT GUIDANCE ON MONDAY
HIGH TEMPS.
&&
.LONG TERM/TUESDAY THROUGH FRIDAY/...
AS OF 3 PM SATURDAY...
A WEAK UPPER RIDGE MANAGES TO BUILD ON TUESDAY AND THIS SHOULD BRING
A MILD AFTERNOON. WEDNESDAY MAY ALSO BRING HIGHS IN THE LOW 70S
AHEAD OF WHAT WILL END UP BEING A PRETTY STRONG COLD FRONT ON
THURSDAY. LITTLE TO NO MOISTURE FLOW AHEAD OF THE FRONT SO ITS
PASSAGE SHOULD BE DRY. THE ECWMF HAS INDICATED OTHERWISE FOR A FEW
RUNS NOW BUT THIS MODEL HAS BEEN DISPLAYING A VERY WET BIAS FOR SOME
TIME LOCALLY IN SUCH SETUPS. DRY AND COOL WEATHER FOR THE REST OF
THE PD WITH HIGHS STRUGGLING TO LOW 60S BY DAY AND UPPER 30S AT
NIGHT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
WEAK LOW PRESSURE WILL MOVE ALONG A STALLED BOUNDARY JUST OFFSHORE
TODAY BRINGING MID LEVEL CLOUD COVER TO THE COASTAL TERMINALS. A
MORE SIGNIFICANT SYSTEM DEVELOPING IN THE GULF OF MEXICO WILL CAUSE
GRADUALLY THICKENING HIGH CLOUDS AT ALL TERMINALS THROUGH THE PERIOD.
4SM VSBY AT LBT IS ONLY RESTRICTION THIS MORNING...AND THIS WILL
BURN OFF QUICKLY AFTER SUNRISE LEAVING VFR ALL TERMINALS. 11U-3.9U
MICRON SATELLITE IS BUSY...WITH HIGH LEVEL CI STREAMING ACROSS TO
THE NE AND MVFR/VFR STRATUS JUST OFFSHORE. WITH A MODERATE NE WIND
TODAY AT AROUND 10 KT...EXPECT SOME OF THIS STRATUS TO OCCASIONALLY
MOVE ONSHORE CREATING 5K FOOT CIGS AT ILM/CRE/MYR. DO NOT BELIEVE
ANY OF THIS WILL GET TO FLO/LBT...BUT SOME AFTN CU MAY DEVELOP AT
THOSE TERMINALS AROUND 4K FEET. THIS CU WILL HAVE VERY LIMITED
VERTICAL EXTENT DUE TO THE DRY MID LEVELS OF THE COLUMN. MODEL
GUIDANCE HAS SLOWED IN ITS PROGRESSION OF THE GULF OF MEXICO
SYSTEM...AND HAVE REMOVED ANY VCSH TO REFLECT THIS MORE DELAYED
SOLUTION. VFR WILL BE THE RULE ALL DAY WITH HIGH LEVEL CI LOWERING
TO AN AS/AC DECK AROUND 12K FEET BY THE END OF THE TAF PERIOD AS THE
COLUMN SATURATES FROM THE TOP DOWN.
EXTENDED OUTLOOK...POTENTIAL IFR DUE TO SHOWERS AND LOW CEILINGS
SUNDAY AND MONDAY. FOG POSSIBLE TUESDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...WILL HOIST A SMALL CRAFT ADVISORY FOR ALL
ZONES EXCEPT AMZ254 WHERE A SMALL CRAFT SHOULD EXERCISE CAUTION
HEADLINE WILL REMAIN IN PLACE. PINCHED GRADIENT HAS DEVELOPED ACROSS
THE WATERS EARLY THIS MORNING...THE RESULT OF PRESSURE DIFFERENCES
BETWEEN WEAK LOW PRESSURE MOVING NE ALONG A STALLED FRONT OFFSHORE
OF THE CAROLINAS AND HIGH PRESSURE CENTERED ACROSS THE OHIO VALLEY.
THIS PINCHED GRADIENT SHOULD RELAX LATER IN THE DAY AS WEAK WAVE OF
LOW PRESSURE MOVES FURTHER AWAY. GRADIENT WILL TIGHTEN UP AGAIN THIS
EVE AND ESPECIALLY OVERNIGHT AS WEDGE OF HIGH PRESSURE INTENSIFIES
ACROSS THE AREA WHILE LOW PRESSURE REACHES THE NORTHEASTERN GULF
COAST. PERSISTENT NE WINDS WILL REACH MARGINAL SMALL CRAFT ADVISORY
LEVELS ACROSS THE MAJORITY OF THE AREA. SEAS WILL NOT CHANGE MUCH
THROUGH THE PERIOD...AND WILL BE AS HIGH AS 5 TO 7 FT ACROSS THE
OUTER WATERS. NEAR SHORE SEAS WILL BE LOWER IN AREAS WHERE FETCH IS
GREATLY REDUCED IN NE FLOW.
SHORT TERM/SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...
SURFACE HIGH PRESSURE WEDGE IN CONTROL ON SUNDAY TO BRING A MODERATE
GRADIENT WIND. SMALL CRAFT ADVISORY FROM NEAR TERM HAS BEEN EXTENDED
THROUGH SUNDAY FOR NORTHERN TWO ZONES AS 6 FT SEAS AFFECT THE OUTER
REACHES ALONG FRYING PAN SHOALS. WAVE SHADOWING WILL PROBABLY
PRECLUDE THIS OVER SOUTHERN WATERS. A FLAT WAVE OF LOW PRESSURE WILL
RIDE UP THE EAST SIDE OF THE WEDGE SUNDAY NIGHT INTO MONDAY. THIS
WILL SLIGHTLY TAPER THE GRADIENT AND COULD LOWER THE SEAS ENOUGH TO
DROP ANY ADVISORIES. WEDGE WEAKENS BUT REMAINS IN PLACE FOR THE
REMAINDER OF MONDAY AND MONDAY NIGHT KEEPING WINDS WITH A NORTHERLY
COMPONENT.
&&
LONG TERM/TUESDAY THROUGH WEDNESDAY/...
AS OF 3 PM SATURDAY...
LOOKS LIKE A FAIRLY QUIET PATTERN FOR MOST OF THE PERIOD. HIGH
PRESSURE REMAINS TO THE NORTH TUESDAY BRINGING A LIGHT NORTHERLY
WIND AND SEAS IN THE 2 TO 3 FT RANGE. CHANGES MAY BE UNDERWAY COME
WEDNESDAY AS THE HIGH BEGINS TO LIFT OUT AHEAD OF AN APPROACHING
COLD FRONT. THE TIMING OF THIS FRONT AND THE EVOLUTION OF SURFACE
FEATURES ASSOCIATED WITH IT IS HIGHLY UNCERTAIN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR AMZ256.
SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...MBB
NEAR TERM...RJD
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...JDW
000
FXUS62 KMHX 211002
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
500 AM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...THEN SLIDE
OFFSHORE TONIGHT. LOW PRESSURE WILL DEVELOP JUST OFFSHORE LATE
SUNDAY AND SUNDAY NIGHT...THEN LIFT NE ON MONDAY. HIGH PRESSURE
WILL REBUILD OVER THE AREA TUESDAY AND WEDNESDAY. A COLD FRONT
WILL APPROACH FROM THE WEST ON THURSDAY AND MOVE OFFSHORE
FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 2 AM SAT...LOW CLOUDS HAVE CLEARING INLAND AND N. MDLS SHOW
LOWS CLOUDS SLOWLY SLIDING S AND E AND EXPECT CLOUDS CURRENTLY
ALONG THE BEACHES WILL DIMINISH THROUGH THE MORNING. NAM FCST
SOUNDING CONT TO SHOW A NEARLY SATURATED LYR NEAR 5000 FT THIS
AFTN SO EXPECT WILL SEE DECENT AMOUNT OF STRATO-CU...WILL ALSO
HAVE SOME HIGH CLOUDS TODAY BUT EXPECT ENUF PEAKS OF SUN TO GET
HIGHS IN THE 60 TO 65 DGR RANGE.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 2 AM SAT...CLOUDS WILL THICKEN TONIGHT AS BEGIN TO SEE LOW
LVL MOISTURE INCREASE PLUS WILL HAVE SOME MID/HIGH CLOUDS WELL
AHEAD OF APPROACHING SRT WAVE. CONT PREV FCST OF SLIGHT POP LATE
TONIGHT SRN TIER. LOWS MAINLY UPR 40S TO LOWER 50S. RAIN WILL BE
INCREASING FROM SW TO NE SUNDAY AS INSENT LIFT INCREASES OVER THE
AREA AS CSTL FRONT TAKES SHAPE JUST OFFSHORE AHEAD OF APPROACHING
SRT WAVE. CONT LIKELY POPS INLAND TO CHC NE CST LATER SUNDAY. SUN
NIGHT LOOKS WET AS ISENT LIFT CONTS WITH INCREASING MID/UPR
SUPPORT WITH SRT WAVE PASSING BY TO THE NW. HAVE CATEGORICAL POPS
ALL AREAS SUN NIGHT. RAIN WILL GRAD DIMINISH FROM SW TO NE MON
HOWEVER WILL STILL HAVE GOOD CVRG EARLY AND CONT CATEGORICAL NE
CST TO LIKELY POPS ELSEWHERE WITH POPS DECREASING TO CHC LATE.
TOTAL QPF FROM THIS EVENT LOOKS TO AVG OUT IN 0.5 TO 1 INCH RANGE AND
DESPITE VERY WET GROUND MANY AREAS SHLD NOT CAUSE SIGNIFICANT
PROBLEMS. HIGHS BOTH SUN AND MON WITH CLOUDS...PRECIP AND NE WINDS
WILL BE MAINLY IN THE UPPER 50S TO LOWER 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 2 AM SAT...ANY LINGERING LIGHT RAIN/DRIZZLE WILL END MON
NIGHT. WITH HIGH PRES BUILDING IN TUE AND WED EXPECT DRY
CONDITIONS. IMPRESSIVE SRT WAVE/COLD FRONT WILL APPROACH THU AND
MOVE OFFSHORE FRI. MDLS DIFFER WITH GFS SHOWING LIMITED MOISTURE
AND BULK OF PRECIP OFFSHORE. EMCWF IS WETTER...ESPCLY CST WITH
MOISTURE COMING IN OFF ATLC. CURRENTLY HAVE CHC POPS THU AND WILL
NOT CHANGE UNTIL GET MORE CLARITY FROM MDLS. COOLER AND DRY FRI IN
WAKE OF FRONT/SRT WAVE.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
CIGS HAVE IMPROVED TO VFR ALL TAF SITES THIS MORNING BUT SOME LCL
MVFR VSBYS LIKELY AT KPGV AND KISO UNTIL 13Z. VFR EXPECTED TO
PREVAIL TODAY INTO TONIGHT WITH HIGH PRES OVER AREA...THOUGH HIGH
CLOUDS INCREASING TODAY AND MID CLOUDS TONIGHT.
LOW PRES MOVING UP FROM SW WILL PRODUCE DETERIORATING CONDITIONS
LATE SUN...WITH WDSPRD IFR SUN NIGHT AND MON. LOWER CIGS LIKELY TO
PERSIST INTO TUE DUE TO WEDGE CONDITIONS IN WAKE OF DEPARTED LOW
PRES.
&&
.MARINE...
WEAK LOW PRES OFF SC COAST RESUTING IN TIGHTER PRES GRAD EARLY THIS
MORNING...AND CONTINUED STRONGER WINDS OVER CENTRAL AND SRN WATERS.
BORDERLINE SCA WINDS OVER PAMLICO SOUNDS BUT RUC AND NAM IDICATE
PERIOD OF STRONGER WINDS PERSISTING THIS MORNING SO POSTED SCA THERE
UNTIL NOON. STONGER WINDS WILL CONTINUE OVER SRN HALF OF WATERS INTO
THIS EVENING...AND SCA SEAS WILL PERSISTING INTO SUN.
STILL SOME MODEL DIFFERENCES ON SFC LOW MOVING UP FROM SW SUN
NIGHT-MON AND LEANED TO SLIGHTLY SLOWER NAM FOR CONTINUITY. 06Z GFS
HAS COME IN LINE WITH THIS SOLUTION AS WELL. EXPECT WINDS AND SEAS
TO INCREASE LATE SUN INTO SUN NIGHT...THEN MAY HAVE WINDS BELOW 20
KT MON WITH LOW MOVING NEAR COAST. CONDITIOSN SLOWLY IMPROVING
TUE-WED.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ150.
&&
$$
SYNOPSIS...RF
NEAR TERM...RF
SHORT TERM...RF
LONG TERM...RF
AVIATION...JBM
MARINE...JBM
000
FXUS62 KRAH 210825
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
322 AM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE TO OUR NORTH WILL BRING NORTHEAST FLOW TO NORTH
CAROLINA INTO SUNDAY. THE NEXT STORM SYSTEM WILL MOVE INTO THE
REGION FROM THE SOUTHWEST AND BRING CLOUDS AND RAIN FOR SUNDAY AND
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM...
SURFACE HIGH PRESSURE NORTH OF NORTH CAROLINA WILL KEEP NORTHEAST
FLOW OVER CENTRAL NORTH CAROLINA INTO TONIGHT. EXPECTING ENOUGH
SUNSHINE THROUGH THE MID AND HIGH CLOUDS TO BRING TEMPERATURES TO
JUST SHORT OF FULL SUN VALUES FOR NORTHEAST FLOW. AFTERNOON HIGHS
UPPER 50S TO LOWER 60S NORTH... AND 62 TO 65 SOUTH.
AN UPPER LEVEL SYSTEM DROPPING INTO TEXAS IS GENERATING SURFACE
LOW PRESSURE IN THE NORTHWEST GULF OF MEXICO AT THIS TIME. BOTH
THESE LOWS FORECAST TO ROUGHLY MOVE EAST NORTHEAST INTO SUNDAY.
THE NAM 700 MILLIBAR PRESSURE FIELD IS PERHAPS TOO WEAK AND PREFER
THE STRONGER MID LEVEL FRONT OF THE CANADIAN AND GFS MODELS. THE
GFS AND CANADIAN DEPICT A 700 MILLIBAR WARM FRONT... BARELY
LIFTING NORTH INTO NORTH CAROLINA BY SUNRISE SUNDAY. ISENTROPIC
LIFT IS QUITE WEAK BELOW THIS FRONT SO ANY RAINFALL SHOULD BE
LATE... WELL UNDER ONE TENTH INCH AND NOT STRAY TOO FAR NORTH BY
SUNRISE. INCREASED LOWER CLOUDINESS AND MORE OF A BREEZE THAN
FRIDAY NIGHT SHOULD YIELD LOW TEMPERATURES IN THE MID TO UPPER
40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 315 AM...
A 700 MILLIBAR WARM FRONT NEAR THE SOUTH CAROLINA BORDER SUNRISE
SUNDAY WILL EXIT TO THE NORTH AFTER SUNSET. GIVEN THE EXPECTED
NORTHWARD PROGRESS OF THE FRONT AND MODERATE TO WEAK ISENTROPIC
LIFT NEAR 850 MILLIBARS... AT LEAST THE SOUTHWEST THREE QUARTERS
SHOULD SEE MEASURABLE RAIN BEFORE SUNSET SUNDAY.
AS THE UPPER SYSTEM LIFTS NORTHEAST THROUGH THE MOUNTAINS SUNDAY
NIGHT... LOW PRESSURE DEVELOPMENT OFF THE CAROLINAS OCCURS AND
BECOMES THE DOMINATE SURFACE LOW. GOOD MID LEVEL ISENTROPIC LIFT
IN THE MID LEVELS SHOULD KEEP RAIN CHANCES HIGH INTO SUNDAY NIGHT.
MOST MODELS DAMP OUT THE PARENT LOW PRESSURE TROUGH AS IT MOVES
NORTHEAST AND KEEP THE SURFACE LOW WEAKER THAN THE CANADIAN AS IT
APPROACHES CAPE HATTERAS. RAINFALL PERHAPS TWO TENTHS INCH
NORTHWEST TO FOUR TENTHS SOUTHEAST SUNDAY NIGHT.
WINDS WEAKEN LATE SUNDAY NIGHT INTO MONDAY AND HEAVIER
PRECIPITATION MAY MISS US TO THE EAST MONDAY. PRECIPITATION MAY
LINGER LONGEST IN THE NORTHEAST WITH THE EXITING SURFACE LOW BUT
RAINFALL AMOUNTS OF ONE TENTH INCH OR LESS EAST... AND MUCH LESS
TO THE WEST. OF COURSE IF THE LOW TRACKS CLOSER TO THE COAST...
THESE AMOUNTS ARE UNDERDONE. ONLY A SLIGHT RAIN CHANCE IN THE
NORTHEAST WITH THE EXITING LOW MONDAY NIGHT.
OVERNIGHT LOWS 45 TO 50 SUNDAY NIGHT... AND MOSTLY MID 40S TUESDAY
NIGHT. SUNDAY HIGH TEMPERATURES NEAR 50 NORTHWEST TO UPPER 50S
SOUTHEAST. IF A COLD AIR MASS DAMMING WEDGE SETS UP AS EXPECTED
MONDAY...A LOW OVERCAST WITH LIGHT RAIN OR DRIZZLE POSSIBLE. THE
CURRENT FORECAST TEN DEGREE DIURNAL RISE TO MONDAY AFTERNOON WOULD
NEED TO BE DROPPED TO THREE TO SIX DEGREES IF CLOUDS ARE ABLE TO
PERSIST INTO EARLY MONDAY EVENING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 315 AM FRIDAY...
ANY LIGHT PRECIP LINGERING INTO MONDAY NIGHT SHOULD BE GONE BY
TUESDAY MORNING...AS SOUTHWESTERLY MID LEVEL FLOW USHERS IN DRIER
AIR ABOVE THE REMAINING CAD AIRMASS. THE POSSIBILITY LINGERING LOW
CLOUDS COULD COMPLICATE THE TEMPERATURE FORECAST ON TUESDAY AS SOME
MOISTURE REMAINS BELOW A SUBSIDENCE INVERSION BENEATH DEVELOPING
SHORTWAVE RIDGING ALOFT. WILL STICK WITH MOS VALUES WITH HIGHS
64-70.
THE FORECAST GETS QUITE A BIT MORE COMPLICATED BEYOND TUESDAY...WITH
THE HANDLING OF A SHORTWAVE EXPECTED TO ENTER THE PACIFIC NORTHWEST
ON MONDAY AND EMERGE OVER THE NORTH CENTRAL PLAINS BY WED. THE
GENERAL TREND IS FOR THE DEVELOPMENT OF A HIGH AMPLITUDE LONGWAVE
TROUGH BY THE END OF THE WEEK...AND WHILE BOTH THE GFS AND ECMWF
RESOLVE SUCH A SOLUTION...THEY CURRENTLY GET THE SIMILAR ANSWER
THROUGH SOMEWHAT DIFFERENT SCENARIOS. THE GFS SENDS THE
AFOREMENTIONED SHORTWAVE ACROSS THE UPPER MIDWEST AND THE LIFTS THE
SYSTEM INTO ONTARIO BY THURSDAY...PUSHING A DRY COLD FRONT INTO
CENTRAL NC WED NIGHT. THIS IS FOLLOWED BY A SECOND SHORTWAVE THAT
DIVES SOUTH THROUGH THE MIDWEST...BUT WITH NO MORE TO WORK
WITH....POINTS EAST OF THE MOUNTAINS STAY DRY EVEN AS A SURFACE WAVE
IS INDUCED OFFSHORE THURSDAY MORNING. THE ECMWF ON THE OTHER HAND
IS MUCH SLOWER WITH THE FIRST SHORTWAVE...ALLOWING MORE MOISTURE TO
BE PULLED NORTH OVER A PERSISTENT SURFACE RIDGE ALONG THE EASTERN
SEABOARD. CYCLOGENESIS ALONG THE COAST SUBSEQUENTLY OCCURS CLOSER
TO THE COAST THURSDAY MORNING WITH LESS EASTWARD PROGRESSION OF THE
SURFACE FRONT...AND THUS THE ECMWF PRODUCES PRECIP OVER THE EASTERN
THIRD OF NC. GIVEN THESE CONTINUED MODEL INCONSISTENCIES...FEEL THE
BEST COURSE OF ACTION IS TO SHOW BELOW NORMAL TEMPS FOR THE END OF
THE WEEK...CONTINUING WITH HIGHER SLIGHT CHANCE POPS IN THE EAST
UNTIL SOME SORT OF MODEL CONVERGENCE BEGINS.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1245 AM SATURDAY...
OTHER THAN PERIODS OF LIMITED VSBYS AT KRWI WHERE LINGERING LOW
LEVEL MOISTURE IS ALREADY CAUSING SOME SHALLOW FOG...VFR CONDITIONS
ARE GENERALLY EXPECTED ACROSS CENTRAL NC THROUGH THE CURRENT TAF
PERIOD. HIGH PRESSURE OVER THE OHIO VALLEY REGION WILL DRIFT SLOWLY
NORTHEAST TODAY...AND SETTLE OVER NEW ENGLAND TONIGHT...KEEPING
SURFACE WINDS PREDOMINATELY OUT OF THE NE. A DEVELOPING SYSTEM
OVER THE WESTERN GULF COAST WILL BEGIN TO LIFT NORTH AND EASTWARD
TODAY...WITH PERIODS OF CIRRUS DRIFTING OVER CENTRAL NC FROM THE
SOUTHWEST. CEILINGS WILL EVENTUALLY BEGIN TO LOWER LATE TONIGHT AND
INTO SUNDAY MORNING AS THE PRECIPITATION SHIELD ASSOCIATED WITH THE
GULF COAST STORM SYSTEM SPREADS TO TOWARDS THE AREA...BUT ALL SITES
SHOULD REMAIN VFR AND PRECIP FREE THROUGH 06Z.
LOOKING BEYOND 00Z SUNDAY: A STORM SYSTEM WILL APPROACH FROM THE
SOUTHWEST SUNDAY MORNING AND MAY BRING MVFR OR IFR CONDITIONS TO THE
REGION FOR SUNDAY THROUGH MONDAY. LOW CIGS ARE EXPECTED TO CLEAR OUT
BY MONDAY AFTERNOON BUT AREAS OF IFR/LIFR FOG MAY DEVELOP LATE
MONDAY NIGHT/TUESDAY MORNING. VFR CONDITIONS ARE ANTICIPATED TUESDAY
MORNING THROUGH WEDNESDAY WITH HIGH PRESSURE BUILDING IN FROM THE
SOUTHWEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
LONG TERM...SMITH
AVIATION...SMITH
000
FXUS62 KRAH 210822
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
322 AM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE TO OUR NORTH WILL BRING NORTHEAST FLOW TO NORTH
CAROLINA INTO SUNDAY. THE NEXT STORM SYSTEM WILL MOVE INTO THE
REGION FROM THE SOUTHWEST AND BRING CLOUDS AND RAIN FOR SUNDAY AND
SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM...
SURFACE HIGH PRESSURE NORTH OF NORTH CAROLINA WILL KEEP NORTHEAST
FLOW OVER CENTRAL NORTH CAROLINA INTO TONIGHT. EXPECTING ENOUGH
SUNSHINE THROUGH THE MID AND HIGH CLOUDS TO BRING TEMPERATURES TO
JUST SHORT OF FULL SUN VALUES FOR NORTHEAST FLOW. AFTERNOON HIGHS
UPPER 50S TO LOWER 60S NORTH... AND 62 TO 65 SOUTH.
AN UPPER LEVEL SYSTEM DROPPING INTO TEXAS IS GENERATING SURFACE
LOW PRESSURE IN THE NORTHWEST GULF OF MEXICO AT THIS TIME. BOTH
THESE LOWS FORECAST TO ROUGHLY MOVE EAST NORTHEAST INTO SUNDAY.
THE NAM 700 MILLIBAR PRESSURE FIELD IS PERHAPS TOO WEAK AND PREFER
THE STRONGER MID LEVEL FRONT OF THE CANADIAN AND GFS MODELS. THE
GFS AND CANADIAN DEPICT A 700 MILLIBAR WARM FRONT... BARELY
LIFTING NORTH INTO NORTH CAROLINA BY SUNRISE SUNDAY. ISENTROPIC
LIFT IS QUITE WEAK BELOW THIS FRONT SO ANY RAINFALL SHOULD BE
LATE... WELL UNDER ONE TENTH INCH AND NOT STRAY TOO FAR NORTH BY
SUNRISE. INCREASED LOWER CLOUDINESS AND MORE OF A BREEZE THAN
FRIDAY NIGHT SHOULD YIELD LOW TEMPERATURES IN THE MID TO UPPER
40S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 315 AM...
A 700 MILLIBAR WARM FRONT NEAR THE SOUTH CAROLINA BORDER SUNRISE
SUNDAY WILL EXIT TO THE NORTH AFTER SUNSET. GIVEN THE EXPECTED
NORTHWARD PROGRESS OF THE FRONT AND MODERATE TO WEAK ISENTROPIC
LIFT NEAR 850 MILLIBARS... AT LEAST THE SOUTHWEST THREE QUARTERS
SHOULD SEE MEASURABLE RAIN BEFORE SUNSET SUNDAY.
AS THE UPPER SYSTEM LIFTS NORTHEAST THROUGH THE MOUNTAINS SUNDAY
NIGHT... LOW PRESSURE DEVELOPMENT OFF THE CAROLINAS OCCURS AND
BECOMES THE DOMINATE SURFACE LOW. GOOD MID LEVEL ISENTROPIC LIFT
IN THE MID LEVELS SHOULD KEEP RAIN CHANCES HIGH INTO SUNDAY NIGHT.
MOST MODELS DAMP OUT THE PARENT LOW PRESSURE TROUGH AS IT MOVES
NORTHEAST AND KEEP THE SURFACE LOW WEAKER THAN THE CANADIAN AS IT
APPROACHES CAPE HATTERAS. RAINFALL PERHAPS TWO TENTHS INCH
NORTHWEST TO FOUR TENTHS SOUTHEAST SUNDAY NIGHT.
WINDS WEAKEN LATE SUNDAY NIGHT INTO MONDAY AND HEAVIER
PRECIPITATION MAY MISS US TO THE EAST MONDAY. PRECIPITATION MAY
LINGER LONGEST IN THE NORTHEAST WITH THE EXITING SURFACE LOW BUT
RAINFALL AMOUNTS OF ONE TENTH INCH OR LESS EAST... AND MUCH LESS
TO THE WEST. OF COURSE IF THE LOW TRACKS CLOSER TO THE COAST...
THESE AMOUNTS ARE UNDERDONE. ONLY A SLIGHT RAIN CHANCE IN THE
NORTHEAST WITH THE EXITING LOW MONDAY NIGHT.
OVERNIGHT LOWS 45 TO 50 SUNDAY NIGHT... AND MOSTLY MID 40S TUESDAY
NIGHT. SUNDAY HIGH TEMPERATURES NEAR 50 NORTHWEST TO UPPER 50S
SOUTHEAST. IF A COLD AIR MASS DAMMING WEDGE SETS UP AS EXPECTED
MONDAY...A LOW OVERCAST WITH LIGHT RAIN OR DRIZZLE POSSIBLE. THE
CURRENT FORECAST TEN DEGREE DIURNAL RISE TO MONDAY AFTERNOON WOULD
NEED TO BE DROPPED TO THREE TO SIX DEGREES IF CLOUDS ARE ABLE TO
PERSIST INTO EARLY MONDAY EVENING.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 105 PM FRIDAY...
TUESDAY THROUGH WEDNESDAY: ELONGATED SOUTHWEST TO NORTHEAST SURFACE
RIDGING... BENEATH BUILDING HEIGHTS IN SOUTHWESTERLY FLOW ALOFT
(AHEAD OF AN EVOLVING CENTRAL AND EVENTUALLY EASTERN CONUS
TROUGH)... SHOULD YIELD DRY AND ABOVE AVERAGE TEMPERATURES. HIGHS 62
TO 69... WARMEST TUESDAY. LOWS WITHIN A FEW DEGREES OF 45.
WEDNESDAY NIGHT THROUGH FRIDAY: A SERIES OF INTENSE SHORTWAVE
TROUGHS ALOFT WILL HELP AMPLIFY THE AFOREMENTIONED UPPER TROUGH
ACROSS THE GREAT LAKES AND INTO THE NORTHEAST THROUGH THE REMAINDER
OF THE PERIOD. CYCLOGENESIS SHOULD ENSUE OFF THE EAST COAST... AS
THE UPPER FORCING APPROACHES THE BAROCLINIC ZONE JUST OFFSHORE.
ACCORDINGLY EXPECT PRECIPITATION CHANCES TO REMAIN SUPPRESSED TO THE
EAST OF CENTRAL NC... THOUGH THERE PROBABLY WILL BE PERIODS OF MID
AND HIGH CLOUDS ASSOCIATED WITH THE APPROACHING UPPER TROUGH/JET
AXIS... PARTICULARLY OVER THE EASTERN HALF OF THE STATE.
TEMPERATURES TREND DOWNWARD AS THE L/W TROUGH AXIS SETTLES IN BY
FRIDAY. HIGHS 60 TO 65 THURSDAY... WITH LOWER TO MIDDLE 50S EXPECTED
FOR FRIDAY. LOWS INTO THE 30S THURSDAY AND FRIDAY NIGHTS.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1245 AM SATURDAY...
OTHER THAN PERIODS OF LIMITED VSBYS AT KRWI WHERE LINGERING LOW
LEVEL MOISTURE IS ALREADY CAUSING SOME SHALLOW FOG...VFR CONDITIONS
ARE GENERALLY EXPECTED ACROSS CENTRAL NC THROUGH THE CURRENT TAF
PERIOD. HIGH PRESSURE OVER THE OHIO VALLEY REGION WILL DRIFT SLOWLY
NORTHEAST TODAY...AND SETTLE OVER NEW ENGLAND TONIGHT...KEEPING
SURFACE WINDS PREDOMINATELY OUT OF THE NE. A DEVELOPING SYSTEM
OVER THE WESTERN GULF COAST WILL BEGIN TO LIFT NORTH AND EASTWARD
TODAY...WITH PERIODS OF CIRRUS DRIFTING OVER CENTRAL NC FROM THE
SOUTHWEST. CEILINGS WILL EVENTUALLY BEGIN TO LOWER LATE TONIGHT AND
INTO SUNDAY MORNING AS THE PRECIPITATION SHIELD ASSOCIATED WITH THE
GULF COAST STORM SYSTEM SPREADS TO TOWARDS THE AREA...BUT ALL SITES
SHOULD REMAIN VFR AND PRECIP FREE THROUGH 06Z.
LOOKING BEYOND 00Z SUNDAY: A STORM SYSTEM WILL APPROACH FROM THE
SOUTHWEST SUNDAY MORNING AND MAY BRING MVFR OR IFR CONDITIONS TO THE
REGION FOR SUNDAY THROUGH MONDAY. LOW CIGS ARE EXPECTED TO CLEAR OUT
BY MONDAY AFTERNOON BUT AREAS OF IFR/LIFR FOG MAY DEVELOP LATE
MONDAY NIGHT/TUESDAY MORNING. VFR CONDITIONS ARE ANTICIPATED TUESDAY
MORNING THROUGH WEDNESDAY WITH HIGH PRESSURE BUILDING IN FROM THE
SOUTHWEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...SMITH
000
FXUS62 KILM 210819
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
319 AM EST SAT NOV 21 2009
.SYNOPSIS...
GULF OF MEXICO MOISTURE WILL OVERRUN A WEDGE OF HIGH PRESSURE THROUGH
SUNDAY. A BRIEF WARMUP IS EXPECTED TUESDAY AND WEDNESDAY. A STRONG
COLD FRONT THURSDAY WILL USHER IN SOME COLDER AIR FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...WEAK WAVE OF LOW PRESSURE WILL MOVE NE THIS
MORNING ALONG A STALLED FRONT LOCATED ACROSS THE OFFSHORE WATERS.
THIS WILL KEEP THICKEST CLOUD COVER ALONG THE COAST. A BROAD AREA OF
HIGH PRESSURE CENTERED ACROSS THE OHIO VALLEY WILL MOVE TO NEW
ENGLAND AND QUEBEC PROVINCE. THIS AREA OF HIGH PRESSURE WILL BEGIN
TO WEDGE ACROSS THE CAROLINAS THIS PERIOD. THIS WILL SET THE STAGE
FOR INCREASING ISENTROPIC UPGLIDE...MAINLY LATE IN THE PERIOD.
AT THIS TIME...IT LOOKS LIKE ALTHOUGH CLOUDS WILL BE PLENTIFUL THIS
PERIOD...AND THICKEST ALONG THE COAST...RAINFALL WILL BE SLOW TO
DEVELOP GIVEN THE DRYNESS IF THE COLUMN BELOW 4 KFT. HOWEVER...WE DO
EXPECT LIGHT RAIN TO BEGIN TO MOVE IN FROM THE SW/DEVELOP ACROSS THE
AREA BY DAYBREAK ON SUN AS COLUMN SATURATES FROM THE TOP DOWN.
WEAK WAVE OF LOW PRESSURE OFFSHORE WILL AID IN REINFORCING COOL NE
FLOW ACROSS THE AREA. COUPLE THIS WITH CLOUDS AND WE EXPECT MAXIMUMS
THIS PERIOD WILL BE HELD TO THE COOLER SIDE OF MODEL CONSENSUS.
COOLEST TEMPS SHOULD BE ACROSS THE CAPE FEAR REGION...BUT STILL ALL
AREAS SHOULD BE AT OR JUST A DEGREE OR TWO BELOW NORMAL. TONIGHT...
AS WEDGE INTENSIFIES ACROSS THE AREA...AND WITH COOL NE FLOW
CONTINUING...TEMPS SHOULD AGAIN BE DOWN IN THE MID 40S TO NEAR 50
DEGREES.
&&
.SHORT TERM/SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...
MOISTURE OVERRUNNING NORTHEASTERLY SURFACE FLOW ASSOCIATED WITH
WEDGE OF HIGH PRESSURE WILL BRING PLENTY OF CLOUDINESS TO START THE
PERIOD. INCREASING ISENTROPIC UPGLIDE WILL ALSO RAMP UP RAIN
CHANCES...ENDING UP IN THE CATEGORICAL RANGE BY EVENING. QPF
FORECAST IS STILL A LITTLE UNCERTAIN AS GUIDANCE HAS REALLY BACKED
OFF WITH RAINFALL WHEN COMPARED TO PREVIOUS DAYS. RAIN CHANCES
REMAIN FAIRLY HIGH SUNDAY NIGHT AS THE WEAKENING LOW JUMPS TO THE
EASTERN SIDE OF THE WEDGE AND ENDS UP OFFSHORE. SOON THEREAFTER RAIN
CHANCES SHOULD TAPER OFF FROM WEST TO EAST EARLY MONDAY. CLOUDS AND
POSSIBLY DRIZZLE COULD LINGER INTO THE MORNING HOURS. MIGHT EVEN SEE
A TREND TOWARDS OVERALL SLOWER PROGRESSION WHICH COULD MEAN DRIZZLE
AND CLOUDS LINGER MOST OF THE DAY. HAVE UNDERCUT GUIDANCE ON MONDAY
HIGH TEMPS.
&&
.LONG TERM/TUESDAY THROUGH FRIDAY/...
AS OF 3 PM SATURDAY...
A WEAK UPPER RIDGE MANAGES TO BUILD ON TUESDAY AND THIS SHOULD BRING
A MILD AFTERNOON. WEDNESDAY MAY ALSO BRING HIGHS IN THE LOW 70S
AHEAD OF WHAT WILL END UP BEING A PRETTY STRONG COLD FRONT ON
THURSDAY. LITTLE TO MOISTURE FLOW AHEAD OF THE FRONT SO ITS PASSAGE
SHOULD BE DRY. THE ECWMF HAS INDICATED OTHERWISE FOR A FEW RUNS NOW
BUT THIS MODEL HAS BEEN DISPLAYING A VERY WET BIAS FOR SOME TIME
LOCALLY IN SUCH SETUPS. DRY AND COOL WEATHER FOR THE REST OF THE PD
WITH HIGHS STRUGGLING TO LOW 60S BY DAY AND UPPER 30S AT NIGHT.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
MVFR STRATOCUMULUS CEILINGS WILL CONTINUE TO AFFECT THE COASTAL
TAF SITES OVERNIGHT. FURTHER INLAND...STRATOCUMULUS DECK SHOULD BE
MORE SCATTERED BELOW A CIRROSTRATUS CEILING. MAY BE SOME MVFR BR AT
KLBT AND KFLO...BUT DEWPOINT DEPRESSIONS ARE STILL PRETTY HIGH SO
ANY BR SHOULD BE PATCHY IN NATURE. NAM MODEL HAS A COASTAL SURFACE
TROUGH THAT COULD PRODUCE PRECIPITATION ALONG THE IMMEDIATE COAST
AROUND 12Z...HOWEVER THE FEATURE IS SO SMALL...WILL NOT INCLUDE IT
THE ILM TAF. CONTINUED NORTHEAST FLOW SATURDAY WITH THICKENING MID
AND HIGH CLOUDS IN ADVANCE OF THE NEXT SYSTEM. PRECIPITATION WILL
APPROACH THE REGION AT THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...SHOWERS AND LOW CEILINGS MOVE BACK IN SATURDAY
NIGHT THROUGH MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...WILL HOIST A SMALL CRAFT ADVISORY FOR ALL
ZONES EXCEPT AMZ254 WHERE A SMALL CRAFT SHOULD EXERCISE CAUTION
HEADLINE WILL REMAIN IN PLACE. PINCHED GRADIENT HAS DEVELOPED ACROSS
THE WATERS EARLY THIS MORNING...THE RESULT OF PRESSURE DIFFERENCES
BETWEEN WEAK LOW PRESSURE MOVING NE ALONG A STALLED FRONT OFFSHORE
OF THE CAROLINAS AND HIGH PRESSURE CENTERED ACROSS THE OHIO VALLEY.
THIS PINCHED GRADIENT SHOULD RELAX LATER IN THE DAY AS WEAK WAVE OF
LOW PRESSURE MOVES FURTHER AWAY. GRADIENT WILL TIGHTEN UP AGAIN THIS
EVE AND ESPECIALLY OVERNIGHT AS WEDGE OF HIGH PRESSURE INTENSIFIES
ACROSS THE AREA WHILE LOW PRESSURE REACHES THE NORTHEASTERN GULF
COAST. PERSISTENT NE WINDS WILL REACH MARGINAL SMALL CRAFT ADVISORY
LEVELS ACROSS THE MAJORITY OF THE AREA. SEAS WILL NOT CHANGE MUCH
THROUGH THE PERIOD...AND WILL BE AS HIGH AS 5 TO 7 FT ACROSS THE
OUTER WATERS. NEAR SHORE SEAS WILL BE LOWER IN AREAS WHERE FETCH IS
GREATLY REDUCED IN NE FLOW.
SHORT TERM/SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...
SURFACE HIGH PRESSURE WEDGE IN CONTROL ON SUNDAY TO BRING A MODERATE
GRADIENT WIND. SMALL CRAFT ADVISORY FROM NEAR TERM HAS BEEN EXTENDED
THROUGH SUNDAY FOR NORTHERN TWO ZONES AS 6 FT SEAS AFFECT THE OUTER
REACHES ALONG FRYING PAN SHOALS. WAVE SHADOWING WILL PROBABLY
PRECLUDE THIS OVER SOUTHERN WATERS. A FLAT WAVE OF LOW PRESSURE WILL
RIDE UP THE EAST SIDE OF THE WEDGE SUNDAY NIGHT INTO MONDAY. THIS
WILL SLIGHTLY TAPER THE GRADIENT AND COULD LOWER THE SEAS ENOUGH TO
DROP ANY ADVISORIES. WEDGE WEAKENS BUT REMAINS IN PLACE FOR THE
REMAINDER OF MONDAY AND MONDAY NIGHT KEEPING WINDS WITH A NORTHERLY
COMPONENT.
&&
LONG TERM/TUESDAY THROUGH WEDNESDAY/...
AS OF 3 PM SATURDAY...
LOOKS LIKE A FAIRLY QUIET PATTERN FOR MOST OF THE PERIOD. HIGH
PRESSURE REMAINS TO THE NORTH TUESDAY BRINGING A LIGHT NORTHERLY
WIND AND SEAS IN THE 2 TO 3 FT RANGE. CHANGES MAY BE UNDERWAY COME
WEDNESDAY AS THE HIGH BEGINS TO LIFT OUT AHEAD OF AN APPROACHING
COLD FRONT. THE TIMING OF THIS FRONT AND THE EVOLUTION OF SURFACE
FEATURES ASSOCIATED WITH IT IS HIGHLY UNCERTAIN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR AMZ256.
SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...MBB
NEAR TERM...RJD
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...RJD/DL
000
FXUS62 KMHX 210715
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
215 AM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH TODAY...THEN SLIDE
OFFSHORE TONIGHT. LOW PRESSURE WILL DEVELOP JUST OFFSHORE LATE
SUNDAY AND SUNDAY NIGHT...THEN LIFT NE ON MONDAY. HIGH PRESSURE
WILL REBUILD OVER THE AREA TUESDAY AND WEDNESDAY. A COLD FRONT
WILL APPROACH FROM THE WEST ON THURSDAY AND MOVE OFFSHORE
FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 2 AM SAT...LOW CLOUDS HAVE CLEARING INLAND AND N. MDLS SHOW
LOWS CLOUDS SLOWLY SLIDING S AND E AND EXPECT CLOUDS CURRENTLY
ALONG THE BEACHES WILL DIMINISH THROUGH THE MORNING. NAM FCST
SOUNDING CONT TO SHOW A NEARLY SATURATED LYR NEAR 5000 FT THIS
AFTN SO EXPECT WILL SEE DECENT AMOUNT OF STRATO-CU...WILL ALSO
HAVE SOME HIGH CLOUDS TODAY BUT EXPECT ENUF PEAKS OF SUN TO GET
HIGHS IN THE 60 TO 65 DGR RANGE.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 2 AM SAT...CLOUDS WILL THICKEN TONIGHT AS BEGIN TO SEE LOW
LVL MOISTURE INCREASE PLUS WILL HAVE SOME MID/HIGH CLOUDS WELL
AHEAD OF APPROACHING SRT WAVE. CONT PREV FCST OF SLIGHT POP LATE
TONIGHT SRN TIER. LOWS MAINLY UPR 40S TO LOWER 50S. RAIN WILL BE
INCREASING FROM SW TO NE SUNDAY AS INSENT LIFT INCREASES OVER THE
AREA AS CSTL FRONT TAKES SHAPE JUST OFFSHORE AHEAD OF APPROACHING
SRT WAVE. CONT LIKELY POPS INLAND TO CHC NE CST LATER SUNDAY. SUN
NIGHT LOOKS WET AS ISENT LIFT CONTS WITH INCREASING MID/UPR
SUPPORT WITH SRT WAVE PASSING BY TO THE NW. HAVE CATEGORICAL POPS
ALL AREAS SUN NIGHT. RAIN WILL GRAD DIMINISH FROM SW TO NE MON
HOWEVER WILL STILL HAVE GOOD CVRG EARLY AND CONT CATEGORICAL NE
CST TO LIKELY POPS ELSEWHERE WITH POPS DECREASING TO CHC LATE.
TOTAL QPF FROM THIS EVENT LOOKS TO AVG OUT IN 0.5 TO 1 INCH RANGE AND
DESPITE VERY WET GROUND MANY AREAS SHLD NOT CAUSE SIGNIFICANT
PROBLEMS. HIGHS BOTH SUN AND MON WITH CLOUDS...PRECIP AND NE WINDS
WILL BE MAINLY IN THE UPPER 50S TO LOWER 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 2 AM SAT...ANY LINGERING LIGHT RAIN/DRIZZLE WILL END MON
NIGHT. WITH HIGH PRES BUILDING IN TUE AND WED EXPECT DRY
CONDITIONS. IMPRESSIVE SRT WAVE/COLD FRONT WILL APPROACH THU AND
MOVE OFFSHORE FRI. MDLS DIFFER WITH GFS SHOWING LIMITED MOISTURE
AND BULK OF PRECIP OFFSHORE. EMCWF IS WETTER...ESPCLY CST WITH
MOISTURE COMING IN OFF ATLC. CURRENTLY HAVE CHC POPS THU AND WILL
NOT CHANGE UNTIL GET MORE CLARITY FROM MDLS. COOLER AND DRY FRI IN
WAKE OF FRONT/SRT WAVE.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 8 PM FRIDAY...CEILINGS GRADUALLY STARTING TO LIFT WITH MVFR
AT ISO...EWN AND OAJ WITH VFR NOW AT PGV. THE TREND WILL BE FOR
THE STUBBORN LOW CLOUDS TO CONTINUE LIFTING THRU THE NIGHTTIME
HOURS AS TIME SECTIONS SHOW DRIER AIR SLOWLY MIXING TO THE
SURFACE. MAY SEE SOME FOG PATCHES TOWARD MORNING.
PREVIOUS DISCUSSION...
NLY FLOW CONTINUES ACROSS RTES TONIGHT. EXTENSIVE LOW CLOUDS
CONTINUE ACROSS ERN NC THIS EVENING BRINGING MVFR CIGS MOST
LOCATIONS TO IFR CIGS ACROSS SRN RTES. CIGS SLOWLY RISE LATE THIS
AFTERNOON WITH DRIER AIR FILTERING INTO THE REGION. VIS SATELLITE
SHOWING CLEARING TO THE NORTH AND WEST AND EXPECT IMPROVING
CONDITIONS ACROSS THE COASTAL PLAIN EARLY THIS EVENING HOWEVER ERN
RTES WILL LIKELY HANG ONTO LOWER CIGS...MAINLY MVFR....THROUGH
MOST OF THE EVENING AND POSSIBLY AFTER MIDNIGHT BEFORE CLEARING.
VFR SAT-SUN WITH HIGH PRES EXTENDING IN...THEN CONDITIONS
LOWERING SUN NIGHT-MON WITH LOW PRES MOVING ACROSS. CONDITIONS
IMPROVING AGAIN MON NIGHT-TUE WITH HIGH PRES AGAIN.
&&
.MARINE...
AS OF 8 PM FRIDAY...UPDATED CWF EARLIER AS SCEC ON THE SOUNDS
EXPIRED. CONTINUE SCA ON COASTAL WATERS AS NE WINDS GUST INTO THE
20S OVER THE COASTAL WATERS WITH SEAS OFFSHORE UP TO 6 TO 7 FEET.
NO OTHER MAJOR CHANGES TO CURRENT COASTAL FORECAST/GRIDS.
PREVIOUS DISCUSSION...
NORTHERLY SURGE CONTINUING TO BRING WINDS AROUND 20 TO 25 KT
ACROSS MOST OF THE WATERS LATE THIS AFTERNOON. WINDS BEGINNING TO
DIMINISH TO THE NORTH AND EXPECT WINDS TO CONTINUE TO GRADUALLY
DIMINISH FROM N TO S LATE THIS EVENING AND OVERNIGHT. SEAS UP TO 7
FT TO CONTINUE FROM DIAMOND SHOALS NWD AND UP TO 6 FT ACROSS THE
SRN COASTAL WATERS...ESPECIALLY OUTER WATERS. SEAS WILL ALSO
GRADUALLY SUBSIDE SAT AND SAT EVENING AND A PERIOD OF SUB SCA
CONDITIONS EXPECTED LATE SAT NIGHT EARLY SUN BEFORE THE NEXT
SYSTEM APPROACHES THE COASTAL WATERS.
LOW CONFIDENCE CONTINUES WITH NEXT LOW PRES SYSTEM AFFECTING AREA
LATE SUN INTO MON AND DID NOT MAKE SIGNIFICANT CHANGE TO PREVIOUS
FCST...KEEPING LOW TRACK OFFSHORE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ156-
158.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ150.
&&
$$
SYNOPSIS...RF
NEAR TERM...RF
SHORT TERM...RF
LONG TERM...RF
AVIATION...CTC/SK
MARINE...CTC/SK
000
FXUS62 KRAH 210548
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1245 AM EST SAT NOV 21 2009
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL DRIFT TO OUR NORTHEAST ON SATURDAY... IN
ADVANCE OF A STORM SYSTEM WHICH WILL MOVE INTO THE REGION FROM THE
SOUTHWEST AND BRING CLOUDS AND RAIN FOR SUNDAY AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 845 PM FRIDAY...
TONIGHT...WILL HAVE TO CONTEND WITH CIRRUS BLOW OFF FROM THE GULF
CONVECTION ASSOCIATED WITH THE DEEPENING SOUTHERN STREAM VORTEX OVER
SOUTHERN TEXAS. MODELS PAINT 70 TO 80 PERCENT 500-300MB MEAN LAYER
RH MOISTURE OVER THE AREA FROM 06Z ON. THESE CLOUDS APPEAR
SUFFICIENTLY OPAQUE ENOUGH ON IR IMAGERY TO IMPACT OVERNIGHT LOWS.
WILL BUMP UP OVERNIGHT LOWS A FEW DEGREES...RANGING FROM AROUND 40
NORTH TO MID 40S SOUTH. SOME PATCHY GROUND FOG IS ALSO POSSIBLE
OVERNIGHT... ESPECIALLY ACROSS THE EASTERN PORTIONS OF THE FORECAST
AREA WHERE HIGHER DEWPOINTS AND LOW T/TD SPREADS RESIDE. OF
COURSE....IF CIRRUS CANOPY IS AS ADVERTISED...IT WOULD CERTAINLY
HELP DETER WIDESPREAD FOG DEVELOPMENT. -CBL
FOR SATURDAY: THE MID LEVEL VORTEX DEEPENING OVER EASTERN TX/OK THIS
AFTERNOON MOVES SLOWLY ACROSS LA/MS THROUGH SATURDAY. MID-UPPER
LEVEL MOISTURE STEADILY INCREASES AND DEEPENS OVER NC... WHILE THE
SURFACE HIGH TO OUR NORTH CONTINUES MOVING NORTHWARD TO A POSITION
OVER LAKE ERIE... WHERE IT BEGINS TO BE SUPPORTED BY CONFLUENT FLOW
ALOFT WITH NORTHERN STREAM SHORTWAVE TROUGHING OVER PA... CAUSING
THE HIGH TO GRADUALLY STRENGTHEN. THIS PATTERN SHOULD ENSURE A
STEADY NORTHEASTERLY FEED OF LOW LEVEL DRY AIR INTO CENTRAL NC...
SETTING US UP FOR DAMMING ONCE THE SURFACE HIGH CAN GET INTO A MORE
FAVORABLE POSITION (OVER THE ST LAWRENCE VALLEY) SATURDAY NIGHT
WHERE IT CAN TAP INTO EVEN COOLER AIR AND STRENGTHEN FURTHER WITH
THE SUPPORT ALOFT PERSISTING. EXPECT STEADILY LOWERING AND
THICKENING CLOUDS THROUGH THE DAY... WITH A FEW LOWER STRATOCUMULUS
OVER THE WESTERN PIEDMONT WITHIN EASTERLY UPSLOPE LOW LEVEL FLOW.
BUT THE MOST ACTION WITH THIS SYSTEM ON SATURDAY WILL BE BANDS OF
CONVECTION OVER AL/GA AND THE NORTHEAST GULF... AND ANY SIGNIFICANT
FORCING TO GENERATE PRECIP OVER NC HOLDS OFF UNTIL AFTER SUNDOWN
SATURDAY WITH NO DISCERNIBLE ISENTROPIC UPGLIDE AND UPPER DIVERGENCE
HOLDING TO OUR SOUTH THROUGH THE DAY... PLUS THE SUBCLOUD LAYER AT
1-3 KM OVER NC REMAINS RATHER DRY. HIGHS 60-65 ARE SUPPORTED BY LOW
LEVEL THICKNESS TRENDS AND ARE NEAR THE LATEST STATISTICAL GUIDANCE.
-GIH
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 315 PM FRIDAY...
THIS PORTION OF THE FORECAST WILL BE DRIVEN BY 1) A STRENGTHENING
(TO NEAR 1028-1034 MB) BUT MIGRATORY CAD SURFACE HIGH... 2) THE
APPROACH OF A DEAMPLIFYING BUT POWERFUL AND COMPLEX SOUTHERN STREAM
TROUGH ALOFT AND ATTENDANT UPPER JET LEFT EXIT REGION.... 3)
CYCLOGENESIS ALONG THE LOW LEVEL BAROCLINIC ZONE OFFSHORE THE EAST
COAST SOUTHWESTWARD INTO THE WESTERN GULF OF MEXICO... AND 4)
RESULTANT ISENTROPIC LIFT ATOP THE COLD DOME OVER INTERIOR NC.
THE OPERATIONAL MODELS ARE ALL OVER THE PLACE REGARDING THE
EVOLUTION OF THESE FEATURES AND RESULTANT TIMING OF THE UPCOMING
POTENTIAL RAIN EVENT OF AROUND A THIRD TO ONE INCH... HIGHLIGHTED BY
A FAST AND HEAVY OVER-THE-WESTERN PIEDMONT GFS LATE SATURDAY
NIGHT... AND THE TOTALLY DRY NAM FROM THE TRIANGLE NORTHWARD THROUGH
THE ENTIRE DAY SUNDAY. FORECAST CONFIDENCE IS ACCORDINGLY RELATIVELY
LOW... BUT WE WILL CONTINUE TO FAVOR THE TIMING OF THE PREVIOUS
FORECAST -- MOST CLOSELY RESEMBLING THE 12Z GEM -- WITH THE BULK OF
THE RAINFALL SUNDAY MORNING OVER THE SOUTHWEST... AND AREA WIDE BY
SUNDAY AFTERNOON AND SUNDAY NIGHT. FORECAST MAX TEMPERATURES SUNDAY
IN THE UPPER 40S NORTHWEST TO UPPER 50S SOUTHEAST COULD BE A FEW
DEGREES TOO COOL (ESPECIALLY ACROSS THE NORTHERN AND EASTERN PORTION
OF THE CWA)... GIVEN THE AFOREMENTIONED TIMING OF THE PRECIPITATION
SHIELD.
ALTHOUGH THE BULK OF THE PRECIPITATION SHOULD BE WINDING DOWN AND
LIFTING NORTHEASTWARD WITH THE COASTAL LOW... LOW CLOUDS AND DRIZZLE
IN NORTH OR NORTHEASTERLY LOW LEVEL FLOW ARE APT TO CONTINUE
THROUGHOUT THE DAY MONDAY (AND PERHAPS INTO MONDAY NIGHT). HAVE
ACCORDINGLY REDUCED HIGH TEMPERATURES BY 4 TO 8 DEGREES INTO THE 56
TO 63 DEGREE RANGE FROM NORTH TO SOUTH.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 105 PM FRIDAY...
TUESDAY THROUGH WEDNESDAY: ELONGATED SOUTHWEST TO NORTHEAST SURFACE
RIDGING... BENEATH BUILDING HEIGHTS IN SOUTHWESTERLY FLOW ALOFT
(AHEAD OF AN EVOLVING CENTRAL AND EVENTUALLY EASTERN CONUS
TROUGH)... SHOULD YIELD DRY AND ABOVE AVERAGE TEMPERATURES. HIGHS 62
TO 69... WARMEST TUESDAY. LOWS WITHIN A FEW DEGREES OF 45.
WEDNESDAY NIGHT THROUGH FRIDAY: A SERIES OF INTENSE SHORTWAVE
TROUGHS ALOFT WILL HELP AMPLIFY THE AFOREMENTIONED UPPER TROUGH
ACROSS THE GREAT LAKES AND INTO THE NORTHEAST THROUGH THE REMAINDER
OF THE PERIOD. CYCLOGENESIS SHOULD ENSUE OFF THE EAST COAST... AS
THE UPPER FORCING APPROACHES THE BAROCLINIC ZONE JUST OFFSHORE.
ACCORDINGLY EXPECT PRECIPITATION CHANCES TO REMAIN SUPPRESSED TO THE
EAST OF CENTRAL NC... THOUGH THERE PROBABLY WILL BE PERIODS OF MID
AND HIGH CLOUDS ASSOCIATED WITH THE APPROACHING UPPER TROUGH/JET
AXIS... PARTICULARLY OVER THE EASTERN HALF OF THE STATE.
TEMPERATURES TREND DOWNWARD AS THE L/W TROUGH AXIS SETTLES IN BY
FRIDAY. HIGHS 60 TO 65 THURSDAY... WITH LOWER TO MIDDLE 50S EXPECTED
FOR FRIDAY. LOWS INTO THE 30S THURSDAY AND FRIDAY NIGHTS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1245 AM SATURDAY...
OTHER THAN PERIODS OF LIMITED VSBYS AT KRWI WHERE LINGERING LOW
LEVEL MOISTURE IS ALREADY CAUSING SOME SHALLOW FOG...VFR CONDITIONS
ARE GENERALLY EXPECTED ACROSS CENTRAL NC THROUGH THE CURRENT TAF
PERIOD. HIGH PRESSURE OVER THE OHIO VALLEY REGION WILL DRIFT SLOWLY
NORTHEAST TODAY...AND SETTLE OVER NEW ENGLAND TONIGHT...KEEPING
SURFACE WINDS PREDOMINATELY OUT OF THE NE. A DEVELOPING SYSTEM
OVER THE WESTERN GULF COAST WILL BEGIN TO LIFT NORTH AND EASTWARD
TODAY...WITH PERIODS OF CIRRUS DRIFTING OVER CENTRAL NC FROM THE
SOUTHWEST. CEILINGS WILL EVENTUALLY BEGIN TO LOWER LATE TONIGHT AND
INTO SUNDAY MORNING AS THE PRECIPITATION SHIELD ASSOCIATED WITH THE
GULF COAST STORM SYSTEM SPREADS TO TOWARDS THE AREA...BUT ALL SITES
SHOULD REMAIN VFR AND PRECIP FREE THROUGH 06Z.
LOOKING BEYOND 00Z SUNDAY: A STORM SYSTEM WILL APPROACH FROM THE
SOUTHWEST SUNDAY MORNING AND MAY BRING MVFR OR IFR CONDITIONS TO THE
REGION FOR SUNDAY THROUGH MONDAY. LOW CIGS ARE EXPECTED TO CLEAR OUT
BY MONDAY AFTERNOON BUT AREAS OF IFR/LIFR FOG MAY DEVELOP LATE
MONDAY NIGHT/TUESDAY MORNING. VFR CONDITIONS ARE ANTICIPATED TUESDAY
MORNING THROUGH WEDNESDAY WITH HIGH PRESSURE BUILDING IN FROM THE
SOUTHWEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMITH
NEAR TERM...HARTFIELD
SHORT TERM...MWS
LONG TERM...MWS
AVIATION...SMITH/BSD
000
FXUS62 KILM 210535
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1235 AM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHWEST THROUGH
SATURDAY. LOW PRESSURE EMERGING FROM THE GULF OF MEXICO WILL BRING
RAIN TO THE EASTERN CAROLINAS SUNDAY THROUGH EARLY MONDAY...PULLING
AWAY TO THE NORTHEAST BY MONDAY AFTERNOON. HIGH PRESSURE WILL RIDGE
BACK ACROSS THE AREA BY TUESDAY AND PERSIST THROUGH FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 9 PM FRIDAY...LOW STRATUS DECK OF CLOUDS AND ITS PROGRESSION
ACROSS THE ILM CWA WILL BE THE FOCUS FOR THE OVERNIGHT. HAVE USED
RUC/NAM 1000-900MB RH LAYER TO IDENTIFY ITS PROGRESSION
SOUTHWARD/INLAND AND ITS AREAL COVERAGE ACROSS THE ILM CWA FOR THE
REMAINDER OF THE OVERNIGHT. ITS COVERAGE TO BASICALLY INCLUDE THE
IMMEDIATE COASTAL COUNTIES AND INLAND BY 1 COUNTY. COULD OBSERVE
PATCHY FOG BUT ITS OCCURRENCE TOO ISOLATED TO INCLUDE. HAVE TWEAKED
UP OVERNITE MINS MAINLY UNDER THE CANOPY OF LOW CLOUDS. NE WINDS TO
STAY MORE ACTIVE CLOSER TO THE COAST AND UNDERNEATH THE STRATUS DECK
AS IT ADVECTS IT SOUTHWARD. QUITE DRY ABOVE THE STRATUS...850MB AND
HIER VIA LATEST NAM MODEL TIME HEIGHT SECTIONS AND THEREFORE DO NOT
EXPECT ANY PCPN OUT OF THESE CLOUDS. UPSTREAM INLAND CI WILL LIKELY
STREAM OVERHEAD FROM THE SW BY DAYLIGHT SATURDAY.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE BUILDING IN FROM THE NORTH WILL
KEEP THE FORECAST AREA DRY ON SAT. UPPER LEVEL MOISTURE ADVECTION
AHEAD OF DEVELOPING GULF COAST STORM WILL RESULT IN A LOT OF MID AND
UPPER LEVEL CLOUDS. ALONG THE COAST COOLER LOW LEVEL FLOW WILL
RESULT IN SOME LOW CU DEVELOPING...BUT WEAK SUBSIDENCE INVERSION
BETWEEN 850 AND 750 MB WILL PREVENT ANY PRECIP FROM FALLING. CLOUD
COVER AND NORTHERLY FLOW WILL KEEP TEMPERATURES A LITTLE COOLER THAN
FRI...RIGHT AROUND CLIMO.
CLOUD BASES LOWER SAT NIGHT INTO SUN WITH CROSS SECTIONS SHOWING THE
ATMOSPHERE BECOMING NEARLY SATURATED FROM THE SURFACE THROUGH 200 MB
AROUND MIDNIGHT WITH LIGHT RAIN DEVELOPING. BEST ISENTROPIC LIFT
ARRIVES SUN MORNING ACROSS SW PORTIONS...SPREADING OVER NE PARTS OF
THE FORECAST AREA BY NOON. CANNOT FIND ANY REASON TO NOT GO WITH
CATEGORICAL POPS ON SUN. BIG QUESTION IS HOW WILL THE SYSTEM EVOLVE
ONCE IT REACHES THE AREA. DO NOT LIKE THE LATEST NAM SOLUTION WHICH
TRACKS MAIN LOW WEST OF THE MOUNTAINS. THE FAVORED SOLUTION...AND
ONE SUPPORTED BY THE LATEST GFS/ECMWF/CANADIAN...TAKES THE LOW INTO
THE SOUTHEAST US AND DEVELOPS A SECONDARY LOW ALONG OR JUST OFF THE
COAST. STILL UNSURE EXACTLY WHERE THIS LOW WILL TRACK...BUT LIKE THE
ECMWF AND CANADIAN SOLUTION WITH THE LOW MOVE NORTHEAST JUST OFF THE
COAST. THIS WOULD KEEP THE ENTIRE AREA IN STRATIFORM PRECIP AND
COOLER NORTHERLY FLOW. HAVE TRENDED HIGHS DOWN TO ACCOUNT FOR
THIS...BUT THERE STILL REMAINS PLENTY OF POTENTIAL FOR THE FORECAST
TO GO AWRY. LOW PASSING OVER OR WEST OF THE AREA WOULD LEAD TO HIGH
TEMPS WHILE A LOW FARTHER OFFSHORE WILL RESULT IN MUCH COOLER TEMPS.
CLOUDS LINGER SUN NIGHT BUT PRECIP WILL BE ENDING AS THE SYSTEM
MOVES OFF TO THE NORTHEAST AND STARTS TO DEEPEN. NORTHERLY FLOW WILL
INCREASE WITH CLOUDS AND MIXING KEEPING LOWS WELL ABOVE CLIMO.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM SATURDAY...WEAK HIGH PRESSURE WILL BUILD IN BEHIND COLD
FRONT MON THROUGH TUES...BUT GFS SHOWS WEAK SHORT WAVE CROSSING THE
AREA MON NIGHT. PCP WATER CLOSE TO AN INCH MON MORNING WILL DECREASE
THROUGH THE DAY REACHING DOWN TO AROUND A HALF INCH BY TUES. ANY
LINGERING PRECIP SHOULD EXIT THE AREA THROUGH MON MORNING. OVERALL
EXPECT VERY DRY MID LEVELS BUT MAY SEE SOME LOW CLOUDS AND DRIZZLE
HANGING AROUND THROUGH TUES MORNING. DRIER WESTERLY FLOW TAKES OVER
THROUGH MID WEEK. TUES NIGHT A COLD FRONT REACHES THE WRN
CAROLINAS...BUT BECOMES VERY DIFFUSE AFTER CROSSING THE MOUNTAINS
INTO THE COASTAL CAROLINAS. MAY NOT SEE MUCH IN THE WAY OF PCP AS
THE FRONT MOVES INTO LOCAL AREA...BUT BOUNDARY WILL REACH THE COAST
WHILE A COASTAL TROUGH BECOMES MORE PRONOUNCED HEADING INTO THURS.
PCP WATER INCREASES BUT MAY BE MORE IN THE WAY OF UPPER LEVEL
MOISTURE IN HIGH CLOUDS IN W-SW JET. GFS KEEPS THIS PCP OFF
SHORE...BUT TOO CLOSE FOR COMFORT AND MAY SEE A WETTER FORECAST FOR
THANKSGIVING DAY...ESPECIALLY ALONG THE COAST. WITH BOUNDARY SO
CLOSE AND FORECAST SO OUT IN TIME...WILL KEEP SOME LOW END POPS IN
FORECAST FOR NOW ESPECIALLY CLOSE TO THE COAST. BY FRI HIGH
AMPLITUDE MID TO UPPER TROUGH SWINGS ACROSS THE EAST COAST SCOURING
OUT ALL THE WEATHER AND BRINGING DRY AND COOL HIGH PRESSURE FOR THE
WEEKEND. DEEP LAYER NW FLOW ADVECTS PLENTY OF DRY AIR IN FOR FRI
WITH PCP WATER DOWN TO A QUARTER INCH OR LESS.
TEMPS WILL HOLD AROUND NORMAL OR ABOVE THROUGH MUCH OF THE WEEK
UNTIL FRI WHEN COLD AND DRY HIGH PRESSURE BUILDS IN.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
MVFR STRATOCUMULUS CEILINGS WILL CONTINUE TO AFFECT THE COASTAL
TAF SITES OVERNIGHT. FURTHER INLAND...STRATOCUMULUS DECK SHOULD BE
MORE SCATTERED BELOW A CIRROSTRATUS CEILING. MAY BE SOME MVFR BR AT
KLBT AND KFLO...BUT DEWPOINT DEPRESSIONS ARE STILL PRETTY HIGH SO
ANY BR SHOULD BE PATCHY IN NATURE. NAM MODEL HAS A COASTAL SURFACE
TROUGH THAT COULD PRODUCE PRECIPITATION ALONG THE IMMEDIATE COAST
AROUND 12Z...HOWEVER THE FEATURE IS SO SMALL...WILL NOT INCLUDE IT
THE ILM TAF. CONTINUED NORTHEAST FLOW SATURDAY WITH THICKENING MID
AND HIGH CLOUDS IN ADVANCE OF THE NEXT SYSTEM. PRECIPITATION WILL
APPROACH THE REGION AT THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...SHOWERS AND LOW CEILINGS MOVE BACK IN SATURDAY
NIGHT THROUGH MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 12 AM SATURDAY...SCEC CONDITIONS ARE EXPECTED ACROSS THE
WATERS INTO SAT DUE TO A TIGHTENED SFC PRESSURE GRADIENT. THE
PRESSURE GRADIENT IS THE RESULT OF A STATIONARY FRONTAL BOUNDARY
OFFSHORE...PARALLEL TO THE CAROLINAS...AND HIGH PRESSURE CENTERED
JUST SE OF THE GREAT LAKES. THIS WILL RESULT IN NE WINDS 15-20 KT
AND SEAS OF 5 FT...LOWER ACROSS THE NEAR SHORE WATERS. AN UNDERLYING
2-3 FT EASTERLY SWELL RUNNING AT 8-9 SECONDS WILL CONTINUE TO
DISSIPATE UNDER THE LOCALLY PRODUCED WIND WAVES.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...NORTHEAST FLOW SAT WILL INCREASE LATER IN THE
DAY AS GRADIENT BEGINS TO TIGHTEN BETWEEN HIGH PRESSURE TO THE NORTH
AND DEVELOPING GULF COAST LOW. CURRENT FORECAST DOES NOT CALL FOR
WINDS TO EXCEED SCA CRITERIA DURING THE PERIOD...BUT THERE REMAINS A
FAIR AMOUNT OF UNCERTAINTY. GULF COAST LOW WILL MOVE NORTHEAST SAT
NIGHT INTO SUN BUT TRACK OF LOW IS THE BIGGEST QUESTION. FAVORED
SCENARIO WOULD BE A SECONDARY LOW TO DEVELOP OFF THE SOUTHEAST
COAST. THIS LOW WOULD THEN MOVE NORTHEAST PASSING EAST OF THE WATERS
SUN INTO SUN NIGHT. ONCE THE LOW PASSES...NORTH TO NORTHEAST WINDS
BECOME OFFSHORE WITH A BRIEF DECREASE IN SPEEDS DURING THE SHIFT.
THINK SCA WILL BE NEEDED AT SOME POINT...LATER SAT OR SAT NIGHT BUT
NOT CONFIDENT ENOUGH TO RAISE IT JUST YET.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM SATURDAY...WEAK HIGH PRESSURE WILL BUILD IN BEHIND
DEPARTING STORM SYSTEM THROUGH TUES. OFF SHORE FLOW BECOMES
NORTHERLY BUT REMAINS VERY LIGHT LIGHT...10 KTS OR LESS THROUGH MUCH
OF PERIOD. SEAS ON A DECREASING TREND THROUGH MON STARTING AROUND
2-4 FT IN THE MORNING AND ENDING AROUND 3 FT BY MON NIGHT. SEAS WILL
REMAIN LOW IN A LIGHT NORTHERLY FLOW THROUGH WED. WITH DEVELOPMENT
OF COASTAL TROUGH HEADING INTO WED NIGHT...SHOULD SEE GRADIENT
TIGHTEN WITH WINDS BECOMING MORE ON SHORE AND SEAS INCREASING BY END
OF PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH/RJD
SHORT TERM...III
LONG TERM...RGZ
AVIATION...HDL/RJD
000
FXUS62 KILM 210321
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
944 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHWEST TODAY
AND SATURDAY. LOW PRESSURE EMERGING FROM THE GULF OF MEXICO WILL
BRING RAIN TO THE EASTERN CAROLINAS SUNDAY THROUGH EARLY
MONDAY...PULLING AWAY TO THE NORTHEAST BY MONDAY AFTERNOON. MILD
WEATHER CONDITIONS CAN BE EXPECTED MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 9 PM FRIDAY...LOW STRATUS DECK OF CLOUDS AND ITS PROGRESSION
ACROSS THE ILM CWA WILL BE THE FOCUS FOR THE OVERNIGHT. HAVE USED
RUC/NAM 1000-900MB RH LAYER TO IDENTIFY ITS PROGRESSION
SOUTHWARD/INLAND AND ITS AREAL COVERAGE ACROSS THE ILM CWA FOR THE
REMAINDER OF THE OVERNIGHT. ITS COVERAGE TO BASICALLY INCLUDE THE
IMMEDIATE COASTAL COUNTIES AND INLAND BY 1 COUNTY. COULD OBSERVE
PATCHY FOG BUT ITS OCCURRENCE TOO ISOLATED TO INCLUDE. HAVE TWEAKED
UP OVERNITE MINS MAINLY UNDER THE CANOPY OF LOW CLOUDS. NE WINDS TO
STAY MORE ACTIVE CLOSER TO THE COAST AND UNDERNEATH THE STRATUS DECK
AS IT ADVECTS IT SOUTHWARD. QUITE DRY ABOVE THE STRATUS...850MB AND
HIER VIA LATEST NAM MODEL TIME HEIGHT SECTIONS AND THEREFORE DO NOT
EXPECT ANY PCPN OUT OF THESE CLOUDS. UPSTREAM INLAND CI WILL LIKELY
STREAM OVERHEAD FROM THE SW BY DAYLIGHT SATURDAY.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE BUILDING IN FROM THE NORTH WILL
KEEP THE FORECAST AREA DRY ON SAT. UPPER LEVEL MOISTURE ADVECTION
AHEAD OF DEVELOPING GULF COAST STORM WILL RESULT IN A LOT OF MID AND
UPPER LEVEL CLOUDS. ALONG THE COAST COOLER LOW LEVEL FLOW WILL
RESULT IN SOME LOW CU DEVELOPING...BUT WEAK SUBSIDENCE INVERSION
BETWEEN 850 AND 750 MB WILL PREVENT ANY PRECIP FROM FALLING. CLOUD
COVER AND NORTHERLY FLOW WILL KEEP TEMPERATURES A LITTLE COOLER THAN
FRI...RIGHT AROUND CLIMO.
CLOUD BASES LOWER SAT NIGHT INTO SUN WITH CROSS SECTIONS SHOWING THE
ATMOSPHERE BECOMING NEARLY SATURATED FROM THE SURFACE THROUGH 200 MB
AROUND MIDNIGHT WITH LIGHT RAIN DEVELOPING. BEST ISENTROPIC LIFT
ARRIVES SUN MORNING ACROSS SW PORTIONS...SPREADING OVER NE PARTS OF
THE FORECAST AREA BY NOON. CANNOT FIND ANY REASON TO NOT GO WITH
CATEGORICAL POPS ON SUN. BIG QUESTION IS HOW WILL THE SYSTEM EVOLVE
ONCE IT REACHES THE AREA. DO NOT LIKE THE LATEST NAM SOLUTION WHICH
TRACKS MAIN LOW WEST OF THE MOUNTAINS. THE FAVORED SOLUTION...AND
ONE SUPPORTED BY THE LATEST GFS/ECMWF/CANADIAN...TAKES THE LOW INTO
THE SOUTHEAST US AND DEVELOPS A SECONDARY LOW ALONG OR JUST OFF THE
COAST. STILL UNSURE EXACTLY WHERE THIS LOW WILL TRACK...BUT LIKE THE
ECMWF AND CANADIAN SOLUTION WITH THE LOW MOVE NORTHEAST JUST OFF THE
COAST. THIS WOULD KEEP THE ENTIRE AREA IN STRATIFORM PRECIP AND
COOLER NORTHERLY FLOW. HAVE TRENDED HIGHS DOWN TO ACCOUNT FOR
THIS...BUT THERE STILL REMAINS PLENTY OF POTENTIAL FOR THE FORECAST
TO GO AWRY. LOW PASSING OVER OR WEST OF THE AREA WOULD LEAD TO HIGH
TEMPS WHILE A LOW FARTHER OFFSHORE WILL RESULT IN MUCH COOLER TEMPS.
CLOUDS LINGER SUN NIGHT BUT PRECIP WILL BE ENDING AS THE SYSTEM
MOVES OFF TO THE NORTHEAST AND STARTS TO DEEPEN. NORTHERLY FLOW WILL
INCREASE WITH CLOUDS AND MIXING KEEPING LOWS WELL ABOVE CLIMO.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM SATURDAY...WEAK HIGH PRESSURE WILL BUILD IN BEHIND COLD
FRONT MON THROUGH TUES...BUT GFS SHOWS WEAK SHORT WAVE CROSSING THE
AREA MON NIGHT. PCP WATER CLOSE TO AN INCH MON MORNING WILL DECREASE
THROUGH THE DAY REACHING DOWN TO AROUND A HALF INCH BY TUES. ANY
LINGERING PRECIP SHOULD EXIT THE AREA THROUGH MON MORNING. OVERALL
EXPECT VERY DRY MID LEVELS BUT MAY SEE SOME LOW CLOUDS AND DRIZZLE
HANGING AROUND THROUGH TUES MORNING. DRIER WESTERLY FLOW TAKES OVER
THROUGH MID WEEK. TUES NIGHT A COLD FRONT REACHES THE WRN
CAROLINAS...BUT BECOMES VERY DIFFUSE AFTER CROSSING THE MOUNTAINS
INTO THE COASTAL CAROLINAS. MAY NOT SEE MUCH IN THE WAY OF PCP AS
THE FRONT MOVES INTO LOCAL AREA...BUT BOUNDARY WILL REACH THE COAST
WHILE A COASTAL TROUGH BECOMES MORE PRONOUNCED HEADING INTO THURS.
PCP WATER INCREASES BUT MAY BE MORE IN THE WAY OF UPPER LEVEL
MOISTURE IN HIGH CLOUDS IN W-SW JET. GFS KEEPS THIS PCP OFF
SHORE...BUT TOO CLOSE FOR COMFORT AND MAY SEE A WETTER FORECAST FOR
THANKSGIVING DAY...ESPECIALLY ALONG THE COAST. WITH BOUNDARY SO
CLOSE AND FORECAST SO OUT IN TIME...WILL KEEP SOME LOW END POPS IN
FORECAST FOR NOW ESPECIALLY CLOSE TO THE COAST. BY FRI HIGH
AMPLITUDE MID TO UPPER TROUGH SWINGS ACROSS THE EAST COAST SCOURING
OUT ALL THE WEATHER AND BRINGING DRY AND COOL HIGH PRESSURE FOR THE
WEEKEND. DEEP LAYER NW FLOW ADVECTS PLENTY OF DRY AIR IN FOR FRI
WITH PCP WATER DOWN TO A QUARTER INCH OR LESS.
TEMPS WILL HOLD AROUND NORMAL OR ABOVE THROUGH MUCH OF THE WEEK
UNTIL FRI WHEN COLD AND DRY HIGH PRESSURE BUILDS IN.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
BIT OF A STRANGE SYNOPTIC SITUATION. HIGH PRESSURE BUILDING IN...BUT
SOME MVFR STRATA CU HAS MANAGED TO WORK ITS WAY UNDERNEATH THE HIGH
PRESSURE AND DOWN THE COAST...AFFECTING JUST ILM AT PRESENT. THINK
THIS DECK COULD WORK ITS WAY WEST AND SOUTH ENOUGH TO AFFECT LBT
AND CRE RESPECTIVELY...BUT IT SHOULD BE JUST A TRANSITORY FEATURE.
SOME LIGHT FOG INLAND POSSIBLE...BUT WINDS ALOFT TOO STRONG TO
SUPPORT ANY HEAVY FOG. SATURDAY...CONTINUED NORTHEAST FLOW WITH A
VFR STRATA CU CEILING EXPECTED. THERE IS AN OUTSIDE CHANCE OF SOME
LIGHT PATCHY RAIN...BUT NOT ENOUGH TO PUT IN THE TAFS. CONTINUED
NORTHEAST FLOW WITH THICKENING AND LOWERING MID AND HIGH CLOUDS IN
ADVANCE OF THE NEXT SYSTEM TOWARD THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...VFR SATURDAY. SHOWERS AND LOW CEILINGS MOVE BACK
IN SATURDAY NIGHT THROUGH MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 9 PM FRIDAY...SCEC CONDITIONS TO CONTINUE ACROSS THE ILM NC
WATERS WHICH MAY NEED TO BE EXTENDED AND EXPANDED TO INCLUDE THE
REMAINDER OF THE ILM WATERS THRU SATURDAY. A TIGHTENED SFC PRESSURE
GRADIENT TO REMAIN ACROSS THE ILM WATERS WHICH WILL EXTEND ACROSS
THE ILM SC WATERS OVERNIGHT INTO SATURDAY. THIS WILL RESULT IN NE
WINDS INCREASING AND BECOMING 15-20 KT THRUOUGHT BY SATURDAY
DAYLIGHT. SEAS 3 TO 5 FT WILL BE ONGOING ACROSS THE ILM NC WATERS
AND WILL EXPAND INTO THE SOUTHERNMOST ILM SC WATERS DURING DAYLIGHT
SATURDAY. THE PRESSURE GRADIENT BETWEEN THE STATIONARY FRONTAL
BOUNDARY PARALLEL TO THE CAROLINAS OFFSHORE AND A SLITELY STRONGER
HIGH THAN ANTICIPATED...CENTERED JUST SE OF THE GREAT LAKES AT THE
MOMENT...HAVE RESULTED WITH THE CONTINUED AND EXPANDING NE 15-20 KT
WIND FLOW ACROSS THE ILM WATERS. THE WINDS HAVE LOCALLY PRODUCED THE
3 TO 5 FT MAINLY WIND DRIVEN SEAS WITH SHORT PERIODS RUNNING 5-7
SECONDS...WHICH WILL BE THE MAINSTAY FOR THE OVERNIGHT PERIOD. AN
UNDERLYING 2-3 FT EASTERLY SWELL RUNNING AT 8-9 SECONDS WILL LIKELY
CONTINUE DISSIPATE UNDER THE LOCALLY PRODUCED WIND WAVES AS TIME
GOES BY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...NORTHEAST FLOW SAT WILL INCREASE LATER IN THE
DAY AS GRADIENT BEGINS TO TIGHTEN BETWEEN HIGH PRESSURE TO THE NORTH
AND DEVELOPING GULF COAST LOW. CURRENT FORECAST DOES NOT CALL FOR
WINDS TO EXCEED SCA CRITERIA DURING THE PERIOD...BUT THERE REMAINS A
FAIR AMOUNT OF UNCERTAINTY. GULF COAST LOW WILL MOVE NORTHEAST SAT
NIGHT INTO SUN BUT TRACK OF LOW IS THE BIGGEST QUESTION. FAVORED
SCENARIO WOULD BE A SECONDARY LOW TO DEVELOP OFF THE SOUTHEAST
COAST. THIS LOW WOULD THEN MOVE NORTHEAST PASSING EAST OF THE WATERS
SUN INTO SUN NIGHT. ONCE THE LOW PASSES...NORTH TO NORTHEAST WINDS
BECOME OFFSHORE WITH A BRIEF DECREASE IN SPEEDS DURING THE SHIFT.
THINK SCA WILL BE NEEDED AT SOME POINT...LATER SAT OR SAT NIGHT BUT
NOT CONFIDENT ENOUGH TO RAISE IT JUST YET.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM SATURDAY...WEAK HIGH PRESSURE WILL BUILD IN BEHIND
DEPARTING STORM SYSTEM THROUGH TUES. OFF SHORE FLOW BECOMES
NORTHERLY BUT REMAINS VERY LIGHT LIGHT...10 KTS OR LESS THROUGH MUCH
OF PERIOD. SEAS ON A DECREASING TREND THROUGH MON STARTING AROUND
2-4 FT IN THE MORNING AND ENDING AROUND 3 FT BY MON NIGHT. SEAS WILL
REMAIN LOW IN A LIGHT NORTHERLY FLOW THROUGH WED. WITH DEVELOPMENT
OF COASTAL TROUGH HEADING INTO WED NIGHT...SHOULD SEE GRADIENT
TIGHTEN WITH WINDS BECOMING MORE ON SHORE AND SEAS INCREASING BY END
OF PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...III
NEAR TERM...DCH
SHORT TERM...III
LONG TERM...RGZ
AVIATION...HDL
000
FXUS62 KRAH 210155
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
850 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO CENTRAL NORTH CAROLINA FROM THE
NORTHWEST THROUGH TONIGHT. THE HIGH WILL DRIFT TO OUR NORTHEAST ON
SATURDAY... IN ADVANCE OF THE NEXT STORM SYSTEM WHICH WILL MOVE INTO
THE REGION FROM THE SOUTHWEST AND BRING CLOUDS AND RAIN FOR SUNDAY
AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 845 PM FRIDAY...
TONIGHT...WILL HAVE TO CONTEND WITH CIRRUS BLOW OFF FROM THE GULF
CONVECTION ASSOCIATED WITH THE DEEPENING SOUTHERN STREAM VORTEX OVER
SOUTHERN TEXAS. MODELS PAINT 70 TO 80 PERCENT 500-300MB MEAN LAYER
RH MOISTURE OVER THE AREA FROM 06Z ON. THESE CLOUDS APPEAR
SUFFICIENTLY OPAQUE ENOUGH ON IR IMAGERY TO IMPACT OVERNIGHT LOWS.
WILL BUMP UP OVERNIGHT LOWS A FEW DEGREES...RANGING FROM AROUND 40
NORTH TO MID 40S SOUTH. SOME PATCHY GROUND FOG IS ALSO POSSIBLE
OVERNIGHT... ESPECIALLY ACROSS THE EASTERN PORTIONS OF THE FORECAST
AREA WHERE HIGHER DEWPOINTS AND LOW T/TD SPREADS RESIDE. OF
COURSE....IF CIRRUS CANOPY IS AS ADVERTISED...IT WOULD CERTAINLY
HELP DETER WIDESPREAD FOG DEVELOPMENT. -CBL
FOR SATURDAY: THE MID LEVEL VORTEX DEEPENING OVER EASTERN TX/OK THIS
AFTERNOON MOVES SLOWLY ACROSS LA/MS THROUGH SATURDAY. MID-UPPER
LEVEL MOISTURE STEADILY INCREASES AND DEEPENS OVER NC... WHILE THE
SURFACE HIGH TO OUR NORTH CONTINUES MOVING NORTHWARD TO A POSITION
OVER LAKE ERIE... WHERE IT BEGINS TO BE SUPPORTED BY CONFLUENT FLOW
ALOFT WITH NORTHERN STREAM SHORTWAVE TROUGHING OVER PA... CAUSING
THE HIGH TO GRADUALLY STRENGTHEN. THIS PATTERN SHOULD ENSURE A
STEADY NORTHEASTERLY FEED OF LOW LEVEL DRY AIR INTO CENTRAL NC...
SETTING US UP FOR DAMMING ONCE THE SURFACE HIGH CAN GET INTO A MORE
FAVORABLE POSITION (OVER THE ST LAWRENCE VALLEY) SATURDAY NIGHT
WHERE IT CAN TAP INTO EVEN COOLER AIR AND STRENGTHEN FURTHER WITH
THE SUPPORT ALOFT PERSISTING. EXPECT STEADILY LOWERING AND
THICKENING CLOUDS THROUGH THE DAY... WITH A FEW LOWER STRATOCUMULUS
OVER THE WESTERN PIEDMONT WITHIN EASTERLY UPSLOPE LOW LEVEL FLOW.
BUT THE MOST ACTION WITH THIS SYSTEM ON SATURDAY WILL BE BANDS OF
CONVECTION OVER AL/GA AND THE NORTHEAST GULF... AND ANY SIGNIFICANT
FORCING TO GENERATE PRECIP OVER NC HOLDS OFF UNTIL AFTER SUNDOWN
SATURDAY WITH NO DISCERNIBLE ISENTROPIC UPGLIDE AND UPPER DIVERGENCE
HOLDING TO OUR SOUTH THROUGH THE DAY... PLUS THE SUBCLOUD LAYER AT
1-3 KM OVER NC REMAINS RATHER DRY. HIGHS 60-65 ARE SUPPORTED BY LOW
LEVEL THICKNESS TRENDS AND ARE NEAR THE LATEST STATISTICAL GUIDANCE.
-GIH
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 315 PM FRIDAY...
THIS PORTION OF THE FORECAST WILL BE DRIVEN BY 1) A STRENGTHENING
(TO NEAR 1028-1034 MB) BUT MIGRATORY CAD SURFACE HIGH... 2) THE
APPROACH OF A DEAMPLIFYING BUT POWERFUL AND COMPLEX SOUTHERN STREAM
TROUGH ALOFT AND ATTENDANT UPPER JET LEFT EXIT REGION.... 3)
CYCLOGENESIS ALONG THE LOW LEVEL BAROCLINIC ZONE OFFSHORE THE EAST
COAST SOUTHWESTWARD INTO THE WESTERN GULF OF MEXICO... AND 4)
RESULTANT ISENTROPIC LIFT ATOP THE COLD DOME OVER INTERIOR NC.
THE OPERATIONAL MODELS ARE ALL OVER THE PLACE REGARDING THE
EVOLUTION OF THESE FEATURES AND RESULTANT TIMING OF THE UPCOMING
POTENTIAL RAIN EVENT OF AROUND A THIRD TO ONE INCH... HIGHLIGHTED BY
A FAST AND HEAVY OVER-THE-WESTERN PIEDMONT GFS LATE SATURDAY
NIGHT... AND THE TOTALLY DRY NAM FROM THE TRIANGLE NORTHWARD THROUGH
THE ENTIRE DAY SUNDAY. FORECAST CONFIDENCE IS ACCORDINGLY RELATIVELY
LOW... BUT WE WILL CONTINUE TO FAVOR THE TIMING OF THE PREVIOUS
FORECAST -- MOST CLOSELY RESEMBLING THE 12Z GEM -- WITH THE BULK OF
THE RAINFALL SUNDAY MORNING OVER THE SOUTHWEST... AND AREA WIDE BY
SUNDAY AFTERNOON AND SUNDAY NIGHT. FORECAST MAX TEMPERATURES SUNDAY
IN THE UPPER 40S NORTHWEST TO UPPER 50S SOUTHEAST COULD BE A FEW
DEGREES TOO COOL (ESPECIALLY ACROSS THE NORTHERN AND EASTERN PORTION
OF THE CWA)... GIVEN THE AFOREMENTIONED TIMING OF THE PRECIPITATION
SHIELD.
ALTHOUGH THE BULK OF THE PRECIPITATION SHOULD BE WINDING DOWN AND
LIFTING NORTHEASTWARD WITH THE COASTAL LOW... LOW CLOUDS AND DRIZZLE
IN NORTH OR NORTHEASTERLY LOW LEVEL FLOW ARE APT TO CONTINUE
THROUGHOUT THE DAY MONDAY (AND PERHAPS INTO MONDAY NIGHT). HAVE
ACCORDINGLY REDUCED HIGH TEMPERATURES BY 4 TO 8 DEGREES INTO THE 56
TO 63 DEGREE RANGE FROM NORTH TO SOUTH.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 105 PM FRIDAY...
TUESDAY THROUGH WEDNESDAY: ELONGATED SOUTHWEST TO NORTHEAST SURFACE
RIDGING... BENEATH BUILDING HEIGHTS IN SOUTHWESTERLY FLOW ALOFT
(AHEAD OF AN EVOLVING CENTRAL AND EVENTUALLY EASTERN CONUS
TROUGH)... SHOULD YIELD DRY AND ABOVE AVERAGE TEMPERATURES. HIGHS 62
TO 69... WARMEST TUESDAY. LOWS WITHIN A FEW DEGREES OF 45.
WEDNESDAY NIGHT THROUGH FRIDAY: A SERIES OF INTENSE SHORTWAVE
TROUGHS ALOFT WILL HELP AMPLIFY THE AFOREMENTIONED UPPER TROUGH
ACROSS THE GREAT LAKES AND INTO THE NORTHEAST THROUGH THE REMAINDER
OF THE PERIOD. CYCLOGENESIS SHOULD ENSUE OFF THE EAST COAST... AS
THE UPPER FORCING APPROACHES THE BAROCLINIC ZONE JUST OFFSHORE.
ACCORDINGLY EXPECT PRECIPITATION CHANCES TO REMAIN SUPPRESSED TO THE
EAST OF CENTRAL NC... THOUGH THERE PROBABLY WILL BE PERIODS OF MID
AND HIGH CLOUDS ASSOCIATED WITH THE APPROACHING UPPER TROUGH/JET
AXIS... PARTICULARLY OVER THE EASTERN HALF OF THE STATE.
TEMPERATURES TREND DOWNWARD AS THE L/W TROUGH AXIS SETTLES IN BY
FRIDAY. HIGHS 60 TO 65 THURSDAY... WITH LOWER TO MIDDLE 50S EXPECTED
FOR FRIDAY. LOWS INTO THE 30S THURSDAY AND FRIDAY NIGHTS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 730 PM FRIDAY...
STRATOCUMULUS HAS FINALLY MOVED TO THE SOUTHEAST OF KRWI THIS
EVENING... WITH VFR CONDITIONS NOW PRESENT AT ALL CENTRAL NORTH
CAROLINA TAF SITES. VFR CONDITIONS WITH UNRESTRICTED CIGS AND VSBYS
ARE GENERALLY EXPECTED AT INT/GSO/RDU/FAY THROUGH THE TAF FORECAST
PERIOD... WITH POSSIBLY A BRIEF PERIOD OF MVFR VSBYS POSSIBLE AROUND
SUNRISE. MEANWHILE AT RWI... MVFR TO IFR CONDITIONS ARE EXPECTED...
WITH POTENTIALLY SOME LIFR CONDITIONS AROUND SUNRISE.
HIGH PRESSURE WILL CONTINUE TO BUILD/EXTEND INTO THE AREA FROM THE
NORTH TONIGHT. HOWEVER... WITH THE PRESSURE GRADIENT RELAXING AND
MIXING ENDING... WINDS WILL BECOME CALM. DRY AIR IS CURRENTLY
FILTERING INTO THE AREA FROM THE NORTH... VIA SURFACE HIGH PRESSURE.
HOWEVER... WITH A TWO DEGREE DEWPOINT DEPRESSION OBSERVED ALREADY AT
KRWI... EXPECT THEY WILL LIKELY SEE SOME LOW STRATUS AND FOG
(MVFR/IFR... POSSIBLY LIFR) OVERNIGHT UNTIL SHORTLY AFTER SUNRISE.
AT INT/GSO/RDU/FAY... DEWPOINT DEPRESSION ARE 7 DEGREES OR
GREATER... AND GIVEN THE BEST LOW LEVEL MOISTURE IS PROGGED TO
REMAIN TO THE EAST OF THESE TAF SITES AND HIGH LEVEL CLOUD COVER
FILTERING INTO THE AREA FROM THE SOUTHWEST VIA THE APPROACHING STORM
SYSTEM... EXPECT ANY FOG WE SEE WILL GENERALLY BE LIMITED TO THE
MVFR CATEGORY.
BY 12 TO 13Z OR SO... LOW STRATUS AND FOG AT RWI SHOULD BEGIN TO
LIFT ALLOWING CONDITIONS TO GO BACK TO RETURN TO VFR. ALL TAF
LOCATIONS SHOULD EXPERIENCE VFR CONDITIONS THROUGH SATURDAY... AS
SURFACE HIGH PRESSURE CONTINUE TO EXTEND INTO THE REGION FROM THE
NORTH. HOWEVER... MID AND HIGH LEVEL CLOUDS WILL INCREASE ACROSS THE
AREA AS A SOUTHERN STREAM STORMS SYSTEM APPROACHES THE REGION FROM
THE SOUTHWEST. WINDS WILL INCREASE TO AROUND 5 TO 8KTS ACROSS MOST
OF THE REGION BY MID MORNING AS DIURNAL MIXING BEGINS AND
AFOREMENTIONED STORM SYSTEM APPROACHES.
LOOKING BEYOND 00Z SUNDAY: A STORM SYSTEM WILL APPROACH FROM
THE SOUTHWEST SATURDAY NIGHT/SUNDAY MORNING AND MAY BRING MVFR OR
IFR CONDITIONS TO THE REGION FOR SUNDAY THROUGH MONDAY. LOW CIGS ARE
EXPECTED TO CLEAR OUT BY MONDAY AFTERNOON BUT AREAS OF IFR/LIFR FOG
MAY DEVELOP LATE MONDAY NIGHT/TUESDAY MORNING. VFR CONDITIONS ARE
ANTICIPATED TUESDAY MORNING THROUGH WEDNESDAY WITH HIGH PRESSURE
BUILDING IN FROM THE SOUTHWEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...MWS
LONG TERM...MWS
AVIATION...LEP/BSD
000
FXUS62 KMHX 210139
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
838 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH THROUGH SATURDAY...
THEN SLIDE OFFSHORE SATURDAY NIGHT. LOW PRESSURE WILL APPROACH
FROM THE SOUTHWEST SUNDAY AND MOVE NORTHEAST JUST OFFSHORE OF
THE COAST SUNDAY NIGHT INTO MONDAY. HIGH PRESSURE WILL REBUILD
OVER THE AREA TUESDAY AND WEDNESDAY. A COLD FRONT APPROACHES
FROM THE WEST ON THURSDAY THE MOVES OFFSHORE FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 830 PM FRI...STILL DEALING WITH STUBBORN LOW CLOUDS TONIGHT.
BASES BEGINNING TO LIFT EVER SO SLIGHTLY...BUT EXPECT CLOUDS TO
LINGER AROUND THROUGH THE OVERNIGHT HOURS...GRADUALLY GIVING WAY TO
PARTLY CLOUDY SKIES AS ATMOSPHERE DRIES OUT FROM THE TOP DOWN.
BUMPED UP OVERNIGHT LOWS A DEGREE OR SO TO ACCOUNT TO
CLOUDS...MAINLY IN THE MID 40S INLAND TO MID 50S FOR THE OUTER
BANKS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
HIGHS SAT WITH PLENTY OF SUN SHLD REACH THE LOW TO MID 60S. AS
HIGH MOVES OFFSHORE TO THE N SAT NIGHT WILL SEE INCREASING
MOISTURE AS LOW LVL FLOW BECOMES MORE ONSHORE. OVERALL ATMS IS DRY
TO START SO NOT LOOKING FOR MUCH RAIN TO DEVELOP SAT
NIGHT...MAINLY LATE NEAR THE COAST. APPROACHING SRT WAVE COMBINED
WITH INCREASING ISENT LIFT SHLD LEAD TO DECENT CVRG OF RAIN SUNDAY
INTO SUNDAY NIGHT. FOR NOW WILL LEAN MORE TWRD NAM/ECMWF KEEPING
MAINLY NE FLOW OVER THE REGION WITH LOW PRES NEAR OR JUST OFF THE
CST LATER SUN INTO MON. THIS WILL ALSO KEEP RAIN THREAT GOING
LONGER THAN PREV FCST INDICATED SO INCREASED POPS TO LIKELY SUN
NIGHT ALL AREAS AND CONT LIKELY INTO MON ESP OVER THE ERN HALF OF
THE AREA. CLOUDS AND PRECIP WILL LIMIT HIGHS TO UPPER 50S TO LOW
60S SUNDAY AND LOWER TO MID 60S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 230 AM FRIDAY...HIGH PRES WILL BUILD IN TUE AND WED WITH
DRY WEATHER. STRONG SHORT WAVE WILL APPROACH THE AREA ON
THANKSGIVING AND WILL INTRODUCE LOW CHC POPS FOR NOW.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
AS OF 8 PM FRIDAY...CEILINGS GRADUALLY STARTING TO LIFT WITH MVFR
AT ISO...EWN AND OAJ WITH VFR NOW AT PGV. THE TREND WILL BE FOR
THE STUBBORN LOW CLOUDS TO CONTINUE LIFTING THRU THE NIGHTTIME
HOURS AS TIME SECTIONS SHOW DRIER AIR SLOWLY MIXING TO THE
SURFACE. MAY SEE SOME FOG PATCHES TOWARD MORNING.
PREVIOUS DISCUSSION...
NLY FLOW CONTINUES ACROSS RTES TONIGHT. EXTENSIVE LOW CLOUDS
CONTINUE ACROSS ERN NC THIS EVENING BRINGING MVFR CIGS MOST
LOCATIONS TO IFR CIGS ACROSS SRN RTES. CIGS SLOWLY RISE LATE THIS
AFTERNOON WITH DRIER AIR FILTERING INTO THE REGION. VIS SATELLITE
SHOWING CLEARING TO THE NORTH AND WEST AND EXPECT IMPROVING
CONDITIONS ACROSS THE COASTAL PLAIN EARLY THIS EVENING HOWEVER ERN
RTES WILL LIKELY HANG ONTO LOWER CIGS...MAINLY MVFR....THROUGH
MOST OF THE EVENING AND POSSIBLY AFTER MIDNIGHT BEFORE CLEARING.
VFR SAT-SUN WITH HIGH PRES EXTENDING IN...THEN CONDITIONS
LOWERING SUN NIGHT-MON WITH LOW PRES MOVING ACROSS. CONDITIONS
IMPROVING AGAIN MON NIGHT-TUE WITH HIGH PRES AGAIN.
&&
.MARINE...
AS OF 8 PM FRIDAY...UPDATED CWF EARLIER AS SCEC ON THE SOUNDS
EXPIRED. CONTINUE SCA ON COASTAL WATERS AS NE WINDS GUST INTO THE
20S OVER THE COASTAL WATERS WITH SEAS OFFSHORE UP TO 6 TO 7 FEET.
NO OTHER MAJOR CHANGES TO CURRENT COASTAL FORECAST/GRIDS.
PREVIOUS DISCUSSION...
NORTHERLY SURGE CONTINUING TO BRING WINDS AROUND 20 TO 25 KT
ACROSS MOST OF THE WATERS LATE THIS AFTERNOON. WINDS BEGINNING TO
DIMINISH TO THE NORTH AND EXPECT WINDS TO CONTINUE TO GRADUALLY
DIMINISH FROM N TO S LATE THIS EVENING AND OVERNIGHT. SEAS UP TO 7
FT TO CONTINUE FROM DIAMOND SHOALS NWD AND UP TO 6 FT ACROSS THE
SRN COASTAL WATERS...ESPECIALLY OUTER WATERS. SEAS WILL ALSO
GRADUALLY SUBSIDE SAT AND SAT EVENING AND A PERIOD OF SUB SCA
CONDITIONS EXPECTED LATE SAT NIGHT EARLY SUN BEFORE THE NEXT
SYSTEM APPROACHES THE COASTAL WATERS.
LOW CONFIDENCE CONTINUES WITH NEXT LOW PRES SYSTEM AFFECTING AREA
LATE SUN INTO MON AND DID NOT MAKE SIGNIFICANT CHANGE TO PREVIOUS
FCST...KEEPING LOW TRACK OFFSHORE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 4 PM EST SATURDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY UNTIL 10 AM EST SATURDAY FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CQD
SHORT TERM...BTC/RF
LONG TERM...BTC/RF
AVIATION...CTC/SK
MARINE...CTC/SK
000
FXUS62 KMHX 210101
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
801 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH THROUGH SATURDAY...
THEN SLIDE OFFSHORE SATURDAY NIGHT. LOW PRESSURE WILL APPROACH
FROM THE SOUTHWEST SUNDAY AND MOVE NORTHEAST JUST OFFSHORE OF
THE COAST SUNDAY NIGHT INTO MONDAY. HIGH PRESSURE WILL REBUILD
OVER THE AREA TUESDAY AND WEDNESDAY. A COLD FRONT APPROACHES
FROM THE WEST ON THURSDAY THE MOVES OFFSHORE FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
STUBBORN LOW CLOUDINESS WILL GRADUALLY GIVE WAY TO CLEARING SKIES
AS ATMOS DRIES OUT FROM THE TOP DOWN TONIGHT BUT MAY LINGER THRU
MUCH OF THE OVERNIGHT ALONG THE COAST AS MOIST LOW LEVEL FLOW
CONTS. THERE MAY BE A SHARP LOW TEMPERATURE GRADIENT GIVEN THE
DIFF IN CLOUD COVER AND ONSHORE FLOW.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
HIGHS SAT WITH PLENTY OF SUN SHLD REACH THE LOW TO MID 60S. AS
HIGH MOVES OFFSHORE TO THE N SAT NIGHT WILL SEE INCREASING
MOISTURE AS LOW LVL FLOW BECOMES MORE ONSHORE. OVERALL ATMS IS DRY
TO START SO NOT LOOKING FOR MUCH RAIN TO DEVELOP SAT
NIGHT...MAINLY LATE NEAR THE COAST. APPROACHING SRT WAVE COMBINED
WITH INCREASING ISENT LIFT SHLD LEAD TO DECENT CVRG OF RAIN SUNDAY
INTO SUNDAY NIGHT. FOR NOW WILL LEAN MORE TWRD NAM/ECMWF KEEPING
MAINLY NE FLOW OVER THE REGION WITH LOW PRES NEAR OR JUST OFF THE
CST LATER SUN INTO MON. THIS WILL ALSO KEEP RAIN THREAT GOING
LONGER THAN PREV FCST INDICATED SO INCREASED POPS TO LIKELY SUN
NIGHT ALL AREAS AND CONT LIKELY INTO MON ESP OVER THE ERN HALF OF
THE AREA. CLOUDS AND PRECIP WILL LIMIT HIGHS TO UPPER 50S TO LOW
60S SUNDAY AND LOWER TO MID 60S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 230 AM FRIDAY...HIGH PRES WILL BUILD IN TUE AND WED WITH
DRY WEATHER. STRONG SHORT WAVE WILL APPROACH THE AREA ON
THANKSGIVING AND WILL INTRODUCE LOW CHC POPS FOR NOW.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
AS OF 8 PM FRIDAY...CEILINGS GRADUALLY STARTING TO LIFT WITH MVFR
AT ISO...EWN AND OAJ WITH VFR NOW AT PGV. THE TREND WILL BE FOR
THE STUBBORN LOW CLOUDS TO CONTINUE LIFTING THRU THE NIGHTTIME
HOURS AS TIME SECTIONS SHOW DRIER AIR SLOWLY MIXING TO THE
SURFACE. MAY SEE SOME FOG PATCHES TOWARD MORNING.
PREVIOUS DISCUSSION...
NLY FLOW CONTINUES ACROSS RTES TONIGHT. EXTENSIVE LOW CLOUDS
CONTINUE ACROSS ERN NC THIS EVENING BRINGING MVFR CIGS MOST
LOCATIONS TO IFR CIGS ACROSS SRN RTES. CIGS SLOWLY RISE LATE THIS
AFTERNOON WITH DRIER AIR FILTERING INTO THE REGION. VIS SATELLITE
SHOWING CLEARING TO THE NORTH AND WEST AND EXPECT IMPROVING
CONDITIONS ACROSS THE COASTAL PLAIN EARLY THIS EVENING HOWEVER ERN
RTES WILL LIKELY HANG ONTO LOWER CIGS...MAINLY MVFR....THROUGH
MOST OF THE EVENING AND POSSIBLY AFTER MIDNIGHT BEFORE CLEARING.
VFR SAT-SUN WITH HIGH PRES EXTENDING IN...THEN CONDITIONS
LOWERING SUN NIGHT-MON WITH LOW PRES MOVING ACROSS. CONDITIONS
IMPROVING AGAIN MON NIGHT-TUE WITH HIGH PRES AGAIN.
&&
.MARINE...
AS OF 8 PM FRIDAY...UPDATED CWF EARLIER AS SCEC ON THE SOUNDS
EXPIRED. CONTINUE SCA ON COASTAL WATERS AS NE WINDS GUST INTO THE
20S OVER THE COASTAL WATERS WITH SEAS OFFSHORE UP TO 6 TO 7 FEET.
NO OTHER MAJOR CHANGES TO CURRENT COASTAL FORECAST/GRIDS.
PREVIOUS DISCUSSION...
NORTHERLY SURGE CONTINUING TO BRING WINDS AROUND 20 TO 25 KT
ACROSS MOST OF THE WATERS LATE THIS AFTERNOON. WINDS BEGINNING TO
DIMINISH TO THE NORTH AND EXPECT WINDS TO CONTINUE TO GRADUALLY
DIMINISH FROM N TO S LATE THIS EVENING AND OVERNIGHT. SEAS UP TO 7
FT TO CONTINUE FROM DIAMOND SHOALS NWD AND UP TO 6 FT ACROSS THE
SRN COASTAL WATERS...ESPECIALLY OUTER WATERS. SEAS WILL ALSO
GRADUALLY SUBSIDE SAT AND SAT EVENING AND A PERIOD OF SUB SCA
CONDITIONS EXPECTED LATE SAT NIGHT EARLY SUN BEFORE THE NEXT
SYSTEM APPROACHES THE COASTAL WATERS.
LOW CONFIDENCE CONTINUES WITH NEXT LOW PRES SYSTEM AFFECTING AREA
LATE SUN INTO MON AND DID NOT MAKE SIGNIFICANT CHANGE TO PREVIOUS
FCST...KEEPING LOW TRACK OFFSHORE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 4 PM EST SATURDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY UNTIL 10 AM EST SATURDAY FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...BTC
SHORT TERM...BTC/RF
LONG TERM...BTC/RF
AVIATION...CTC/SK
MARINE...CTC/SK
000
FXUS62 KRAH 210100
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
755 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO CENTRAL NORTH CAROLINA FROM THE
NORTHWEST THROUGH TONIGHT. THE HIGH WILL DRIFT TO OUR NORTHEAST ON
SATURDAY... IN ADVANCE OF THE NEXT STORM SYSTEM WHICH WILL MOVE INTO
THE REGION FROM THE SOUTHWEST AND BRING CLOUDS AND RAIN FOR SUNDAY
AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1235 PM FRIDAY...
FOR THE REST OF TODAY THROUGH TONIGHT: THE LATEST SURFACE ANALYSIS
DEPICTS THE FRONT JUST OFF THE OUTER BANKS WITH THE INCOMING SURFACE
HIGH CENTERED OVER EASTERN KY. A DRY AND SUBSIDING COLUMN SHOULD
KEEP MOST AREAS RELATIVELY FREE FROM CLOUDS THROUGH THIS EVENING.
THE EXCEPTION IS OVER NORTHEAST NC WHERE A SURGE OF MOISTURE JUST
OFF THE SURFACE... NOTED WELL ON THE 12Z 925 MB ANALYSIS AND VISIBLE
SATELLITE IMAGERY... CONTINUES MOVING TOWARD THE SOUTH-SOUTHWEST
JUST AHEAD OF A SECONDARY LOW LEVEL COLD FRONT. THE 12Z/20 12KM NAM
SHOWED THIS FEATURE QUITE WELL... AND FAVORS PARTLY TO MOSTLY CLOUDY
SKIES SPREADING TO THE SOUTH-SOUTHWEST OVER EASTERN NC THROUGH THE
REST OF THIS AFTERNOON. FACTORING IN LOW LEVEL THICKNESSES... THE
CLOUDS IN THE EASTERN CWA... AND MOSTLY SUNNY SKIES ELSEWHERE...
STILL EXPECT HIGHS IN THE MID-UPPER 60S... COOLEST ACROSS THE NORTH
WHERE THE COLD AIR ADVECTION IS MOST PROFOUND. BEHIND THE SURGE OF
LOW LEVEL MOISTURE... SKIES SHOULD BE LARGELY CLOUD-FREE
OVERNIGHT... HOWEVER AS THE SURFACE HIGH SHIFTS UP INTO WV...
SURFACE WINDS IN NC SHOULD BECOME UNIFORM NORTHEASTERLY... AND GIVEN
THE MINOR AMOUNT OF RESIDUAL LOW LEVEL MOISTURE... THE UPSLOPE FLOW
AND RESULTANT LIFT/CONDENSATION COULD LEAD TO POCKETS OF STRATUS IN
THE EXTREME WESTERN CWA LATE TONIGHT. HIGH THIN CLOUDS BLOWING OFF
OF THE GULF COAST CONVECTION... ASSOCIATED WITH OUR NEXT STORM
SYSTEM... WILL START TO SPREAD SOUTHWEST TO NORTHEAST ACROSS THE
STATE LATE TONIGHT AS WELL. UNDER GENERALLY FAIR SKIES... STILL
EXPECT LOWS OF 39-46.
FOR SATURDAY: THE MID LEVEL VORTEX DEEPENING OVER EASTERN TX/OK THIS
AFTERNOON MOVES SLOWLY ACROSS LA/MS THROUGH SATURDAY. MID-UPPER
LEVEL MOISTURE STEADILY INCREASES AND DEEPENS OVER NC... WHILE THE
SURFACE HIGH TO OUR NORTH CONTINUES MOVING NORTHWARD TO A POSITION
OVER LAKE ERIE... WHERE IT BEGINS TO BE SUPPORTED BY CONFLUENT FLOW
ALOFT WITH NORTHERN STREAM SHORTWAVE TROUGHING OVER PA... CAUSING
THE HIGH TO GRADUALLY STRENGTHEN. THIS PATTERN SHOULD ENSURE A
STEADY NORTHEASTERLY FEED OF LOW LEVEL DRY AIR INTO CENTRAL NC...
SETTING US UP FOR DAMMING ONCE THE SURFACE HIGH CAN GET INTO A MORE
FAVORABLE POSITION (OVER THE ST LAWRENCE VALLEY) SATURDAY NIGHT
WHERE IT CAN TAP INTO EVEN COOLER AIR AND STRENGTHEN FURTHER WITH
THE SUPPORT ALOFT PERSISTING. EXPECT STEADILY LOWERING AND
THICKENING CLOUDS THROUGH THE DAY... WITH A FEW LOWER STRATOCUMULUS
OVER THE WESTERN PIEDMONT WITHIN EASTERLY UPSLOPE LOW LEVEL FLOW.
BUT THE MOST ACTION WITH THIS SYSTEM ON SATURDAY WILL BE BANDS OF
CONVECTION OVER AL/GA AND THE NORTHEAST GULF... AND ANY SIGNIFICANT
FORCING TO GENERATE PRECIP OVER NC HOLDS OFF UNTIL AFTER SUNDOWN
SATURDAY WITH NO DISCERNIBLE ISENTROPIC UPGLIDE AND UPPER DIVERGENCE
HOLDING TO OUR SOUTH THROUGH THE DAY... PLUS THE SUBCLOUD LAYER AT
1-3 KM OVER NC REMAINS RATHER DRY. HIGHS 60-65 ARE SUPPORTED BY LOW
LEVEL THICKNESS TRENDS AND ARE NEAR THE LATEST STATISTICAL GUIDANCE.
-GIH
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 315 PM FRIDAY...
THIS PORTION OF THE FORECAST WILL BE DRIVEN BY 1) A STRENGTHENING
(TO NEAR 1028-1034 MB) BUT MIGRATORY CAD SURFACE HIGH... 2) THE
APPROACH OF A DEAMPLIFYING BUT POWERFUL AND COMPLEX SOUTHERN STREAM
TROUGH ALOFT AND ATTENDANT UPPER JET LEFT EXIT REGION.... 3)
CYCLOGENESIS ALONG THE LOW LEVEL BAROCLINIC ZONE OFFSHORE THE EAST
COAST SOUTHWESTWARD INTO THE WESTERN GULF OF MEXICO... AND 4)
RESULTANT ISENTROPIC LIFT ATOP THE COLD DOME OVER INTERIOR NC.
THE OPERATIONAL MODELS ARE ALL OVER THE PLACE REGARDING THE
EVOLUTION OF THESE FEATURES AND RESULTANT TIMING OF THE UPCOMING
POTENTIAL RAIN EVENT OF AROUND A THIRD TO ONE INCH... HIGHLIGHTED BY
A FAST AND HEAVY OVER-THE-WESTERN PIEDMONT GFS LATE SATURDAY
NIGHT... AND THE TOTALLY DRY NAM FROM THE TRIANGLE NORTHWARD THROUGH
THE ENTIRE DAY SUNDAY. FORECAST CONFIDENCE IS ACCORDINGLY RELATIVELY
LOW... BUT WE WILL CONTINUE TO FAVOR THE TIMING OF THE PREVIOUS
FORECAST -- MOST CLOSELY RESEMBLING THE 12Z GEM -- WITH THE BULK OF
THE RAINFALL SUNDAY MORNING OVER THE SOUTHWEST... AND AREA WIDE BY
SUNDAY AFTERNOON AND SUNDAY NIGHT. FORECAST MAX TEMPERATURES SUNDAY
IN THE UPPER 40S NORTHWEST TO UPPER 50S SOUTHEAST COULD BE A FEW
DEGREES TOO COOL (ESPECIALLY ACROSS THE NORTHERN AND EASTERN PORTION
OF THE CWA)... GIVEN THE AFOREMENTIONED TIMING OF THE PRECIPITATION
SHIELD.
ALTHOUGH THE BULK OF THE PRECIPITATION SHOULD BE WINDING DOWN AND
LIFTING NORTHEASTWARD WITH THE COASTAL LOW... LOW CLOUDS AND DRIZZLE
IN NORTH OR NORTHEASTERLY LOW LEVEL FLOW ARE APT TO CONTINUE
THROUGHOUT THE DAY MONDAY (AND PERHAPS INTO MONDAY NIGHT). HAVE
ACCORDINGLY REDUCED HIGH TEMPERATURES BY 4 TO 8 DEGREES INTO THE 56
TO 63 DEGREE RANGE FROM NORTH TO SOUTH.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 105 PM FRIDAY...
TUESDAY THROUGH WEDNESDAY: ELONGATED SOUTHWEST TO NORTHEAST SURFACE
RIDGING... BENEATH BUILDING HEIGHTS IN SOUTHWESTERLY FLOW ALOFT
(AHEAD OF AN EVOLVING CENTRAL AND EVENTUALLY EASTERN CONUS
TROUGH)... SHOULD YIELD DRY AND ABOVE AVERAGE TEMPERATURES. HIGHS 62
TO 69... WARMEST TUESDAY. LOWS WITHIN A FEW DEGREES OF 45.
WEDNESDAY NIGHT THROUGH FRIDAY: A SERIES OF INTENSE SHORTWAVE
TROUGHS ALOFT WILL HELP AMPLIFY THE AFOREMENTIONED UPPER TROUGH
ACROSS THE GREAT LAKES AND INTO THE NORTHEAST THROUGH THE REMAINDER
OF THE PERIOD. CYCLOGENESIS SHOULD ENSUE OFF THE EAST COAST... AS
THE UPPER FORCING APPROACHES THE BAROCLINIC ZONE JUST OFFSHORE.
ACCORDINGLY EXPECT PRECIPITATION CHANCES TO REMAIN SUPPRESSED TO THE
EAST OF CENTRAL NC... THOUGH THERE PROBABLY WILL BE PERIODS OF MID
AND HIGH CLOUDS ASSOCIATED WITH THE APPROACHING UPPER TROUGH/JET
AXIS... PARTICULARLY OVER THE EASTERN HALF OF THE STATE.
TEMPERATURES TREND DOWNWARD AS THE L/W TROUGH AXIS SETTLES IN BY
FRIDAY. HIGHS 60 TO 65 THURSDAY... WITH LOWER TO MIDDLE 50S EXPECTED
FOR FRIDAY. LOWS INTO THE 30S THURSDAY AND FRIDAY NIGHTS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 730 PM FRIDAY...
STRATOCUMULUS HAS FINALLY MOVED TO THE SOUTHEAST OF KRWI THIS
EVENING... WITH VFR CONDITIONS NOW PRESENT AT ALL CENTRAL NORTH
CAROLINA TAF SITES. VFR CONDITIONS WITH UNRESTRICTED CIGS AND VSBYS
ARE GENERALLY EXPECTED AT INT/GSO/RDU/FAY THROUGH THE TAF FORECAST
PERIOD... WITH POSSIBLY A BRIEF PERIOD OF MVFR VSBYS POSSIBLE AROUND
SUNRISE. MEANWHILE AT RWI... MVFR TO IFR CONDITIONS ARE EXPECTED...
WITH POTENTIALLY SOME LIFR CONDITIONS AROUND SUNRISE.
HIGH PRESSURE WILL CONTINUE TO BUILD/EXTEND INTO THE AREA FROM THE
NORTH TONIGHT. HOWEVER... WITH THE PRESSURE GRADIENT RELAXING AND
MIXING ENDING... WINDS WILL BECOME CALM. DRY AIR IS CURRENTLY
FILTERING INTO THE AREA FROM THE NORTH... VIA SURFACE HIGH PRESSURE.
HOWEVER... WITH A TWO DEGREE DEWPOINT DEPRESSION OBSERVED ALREADY AT
KRWI... EXPECT THEY WILL LIKELY SEE SOME LOW STRATUS AND FOG
(MVFR/IFR... POSSIBLY LIFR) OVERNIGHT UNTIL SHORTLY AFTER SUNRISE.
AT INT/GSO/RDU/FAY... DEWPOINT DEPRESSION ARE 7 DEGREES OR
GREATER... AND GIVEN THE BEST LOW LEVEL MOISTURE IS PROGGED TO
REMAIN TO THE EAST OF THESE TAF SITES AND HIGH LEVEL CLOUD COVER
FILTERING INTO THE AREA FROM THE SOUTHWEST VIA THE APPROACHING STORM
SYSTEM... EXPECT ANY FOG WE SEE WILL GENERALLY BE LIMITED TO THE
MVFR CATEGORY.
BY 12 TO 13Z OR SO... LOW STRATUS AND FOG AT RWI SHOULD BEGIN TO
LIFT ALLOWING CONDITIONS TO GO BACK TO RETURN TO VFR. ALL TAF
LOCATIONS SHOULD EXPERIENCE VFR CONDITIONS THROUGH SATURDAY... AS
SURFACE HIGH PRESSURE CONTINUE TO EXTEND INTO THE REGION FROM THE
NORTH. HOWEVER... MID AND HIGH LEVEL CLOUDS WILL INCREASE ACROSS THE
AREA AS A SOUTHERN STREAM STORMS SYSTEM APPROACHES THE REGION FROM
THE SOUTHWEST. WINDS WILL INCREASE TO AROUND 5 TO 8KTS ACROSS MOST
OF THE REGION BY MID MORNING AS DIURNAL MIXING BEGINS AND
AFOREMENTIONED STORM SYSTEM APPROACHES.
LOOKING BEYOND 00Z SUNDAY: A STORM SYSTEM WILL APPROACH FROM
THE SOUTHWEST SATURDAY NIGHT/SUNDAY MORNING AND MAY BRING MVFR OR
IFR CONDITIONS TO THE REGION FOR SUNDAY THROUGH MONDAY. LOW CIGS ARE
EXPECTED TO CLEAR OUT BY MONDAY AFTERNOON BUT AREAS OF IFR/LIFR FOG
MAY DEVELOP LATE MONDAY NIGHT/TUESDAY MORNING. VFR CONDITIONS ARE
ANTICIPATED TUESDAY MORNING THROUGH WEDNESDAY WITH HIGH PRESSURE
BUILDING IN FROM THE SOUTHWEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...MWS
LONG TERM...MWS
AVIATION...LEP/BSD
000
FXUS62 KILM 202311
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
610 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHWEST TODAY
AND SATURDAY. LOW PRESSURE EMERGING FROM THE GULF OF MEXICO WILL
BRING RAIN TO THE EASTERN CAROLINAS SUNDAY THROUGH EARLY
MONDAY...PULLING AWAY TO THE NORTHEAST BY MONDAY AFTERNOON. MILD
WEATHER CONDITIONS CAN BE EXPECTED MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 3 PM FRIDAY...HIGH PRESSURE CENTERED OVER KENTUCKY WILL BUILD
EAST OVER THE FORECAST AREA THRU THE NEAR TERM. PRESENT NORTHERLY
FLOW OF AROUND 10 KTS WILL VEER NORTHEAST THIS EVENING AS HIGH
PRESSURE BUILDS IN. DO NOT EXPECT WINDS TO DECOUPLE AS GRADIENT WILL
TIGHTEN UP OVERNIGHT AND WILL MAINTAIN A NORTHEASTERLY BREEZE OF
RIGHT AROUND 5 KTS. TIME HEIGHT CROSS SECTIONS AND SATELLITE LOOPS
INDICATE INCREASING CIRRUS MOVING IN OVERNIGHT. OTHERWISE...LOWER
AND MID LEVELS WILL REMAIN VERY DRY AND STABLE OVERNIGHT WITH NO
CHANCE OF PRECIPITATION. QUITE A BIT OF CLOUD COVER AT AROUND 5
THOUSAND FEET IS NOW ADVECTING DOWN THE COAST IN THE NORTHERLY FLOW.
THESE CLOUDS ARE THINNING OUT AS THEY ARE MOVING IN SO DO NOT EXPECT
COMPLETELY OVERCAST ALTHOUGH OUR NC COASTAL COUNTIES WILL SEE BROKEN
SKIES AT TIMES. MODEL CONSENSUS HAS OVERNIGHT TEMPS REMAINING A TAD
ABOVE NORMAL...FROM MID 40S INLAND TO AROUND 50 AT THE BEACHES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE BUILDING IN FROM THE NORTH WILL
KEEP THE FORECAST AREA DRY ON SAT. UPPER LEVEL MOISTURE ADVECTION
AHEAD OF DEVELOPING GULF COAST STORM WILL RESULT IN A LOT OF MID AND
UPPER LEVEL CLOUDS. ALONG THE COAST COOLER LOW LEVEL FLOW WILL
RESULT IN SOME LOW CU DEVELOPING...BUT WEAK SUBSIDENCE INVERSION
BETWEEN 850 AND 750 MB WILL PREVENT ANY PRECIP FROM FALLING. CLOUD
COVER AND NORTHERLY FLOW WILL KEEP TEMPERATURES A LITTLE COOLER THAN
FRI...RIGHT AROUND CLIMO.
CLOUD BASES LOWER SAT NIGHT INTO SUN WITH CROSS SECTIONS SHOWING THE
ATMOSPHERE BECOMING NEARLY SATURATED FROM THE SURFACE THROUGH 200 MB
AROUND MIDNIGHT WITH LIGHT RAIN DEVELOPING. BEST ISENTROPIC LIFT
ARRIVES SUN MORNING ACROSS SW PORTIONS...SPREADING OVER NE PARTS OF
THE FORECAST AREA BY NOON. CANNOT FIND ANY REASON TO NOT GO WITH
CATEGORICAL POPS ON SUN. BIG QUESTION IS HOW WILL THE SYSTEM EVOLVE
ONCE IT REACHES THE AREA. DO NOT LIKE THE LATEST NAM SOLUTION WHICH
TRACKS MAIN LOW WEST OF THE MOUNTAINS. THE FAVORED SOLUTION...AND
ONE SUPPORTED BY THE LATEST GFS/ECMWF/CANADIAN...TAKES THE LOW INTO
THE SOUTHEAST US AND DEVELOPS A SECONDARY LOW ALONG OR JUST OFF THE
COAST. STILL UNSURE EXACTLY WHERE THIS LOW WILL TRACK...BUT LIKE THE
ECMWF AND CANADIAN SOLUTION WITH THE LOW MOVE NORTHEAST JUST OFF THE
COAST. THIS WOULD KEEP THE ENTIRE AREA IN STRATIFORM PRECIP AND
COOLER NORTHERLY FLOW. HAVE TRENDED HIGHS DOWN TO ACCOUNT FOR
THIS...BUT THERE STILL REMAINS PLENTY OF POTENTIAL FOR THE FORECAST
TO GO AWRY. LOW PASSING OVER OR WEST OF THE AREA WOULD LEAD TO HIGH
TEMPS WHILE A LOW FARTHER OFFSHORE WILL RESULT IN MUCH COOLER TEMPS.
CLOUDS LINGER SUN NIGHT BUT PRECIP WILL BE ENDING AS THE SYSTEM
MOVES OFF TO THE NORTHEAST AND STARTS TO DEEPEN. NORTHERLY FLOW WILL
INCREASE WITH CLOUDS AND MIXING KEEPING LOWS WELL ABOVE CLIMO.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM SATURDAY...WEAK HIGH PRESSURE WILL BUILD IN BEHIND COLD
FRONT MON THROUGH TUES...BUT GFS SHOWS WEAK SHORT WAVE CROSSING THE
AREA MON NIGHT. PCP WATER CLOSE TO AN INCH MON MORNING WILL DECREASE
THROUGH THE DAY REACHING DOWN TO AROUND A HALF INCH BY TUES. ANY
LINGERING PRECIP SHOULD EXIT THE AREA THROUGH MON MORNING. OVERALL
EXPECT VERY DRY MID LEVELS BUT MAY SEE SOME LOW CLOUDS AND DRIZZLE
HANGING AROUND THROUGH TUES MORNING. DRIER WESTERLY FLOW TAKES OVER
THROUGH MID WEEK. TUES NIGHT A COLD FRONT REACHES THE WRN
CAROLINAS...BUT BECOMES VERY DIFFUSE AFTER CROSSING THE MOUNTAINS
INTO THE COASTAL CAROLINAS. MAY NOT SEE MUCH IN THE WAY OF PCP AS
THE FRONT MOVES INTO LOCAL AREA...BUT BOUNDARY WILL REACH THE COAST
WHILE A COASTAL TROUGH BECOMES MORE PRONOUNCED HEADING INTO THURS.
PCP WATER INCREASES BUT MAY BE MORE IN THE WAY OF UPPER LEVEL
MOISTURE IN HIGH CLOUDS IN W-SW JET. GFS KEEPS THIS PCP OFF
SHORE...BUT TOO CLOSE FOR COMFORT AND MAY SEE A WETTER FORECAST FOR
THANKSGIVING DAY...ESPECIALLY ALONG THE COAST. WITH BOUNDARY SO
CLOSE AND FORECAST SO OUT IN TIME...WILL KEEP SOME LOW END POPS IN
FORECAST FOR NOW ESPECIALLY CLOSE TO THE COAST. BY FRI HIGH
AMPLITUDE MID TO UPPER TROUGH SWINGS ACROSS THE EAST COAST SCOURING
OUT ALL THE WEATHER AND BRINGING DRY AND COOL HIGH PRESSURE FOR THE
WEEKEND. DEEP LAYER NW FLOW ADVECTS PLENTY OF DRY AIR IN FOR FRI
WITH PCP WATER DOWN TO A QUARTER INCH OR LESS.
TEMPS WILL HOLD AROUND NORMAL OR ABOVE THROUGH MUCH OF THE WEEK
UNTIL FRI WHEN COLD AND DRY HIGH PRESSURE BUILDS IN.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
BIT OF A STRANGE SYNOPTIC SITUATION. HIGH PRESSURE BUILDING IN...BUT
SOME MVFR STRATA CU HAS MANAGED TO WORK ITS WAY UNDERNEATH THE HIGH
PRESSURE AND DOWN THE COAST...AFFECTING JUST ILM AT PRESENT. THINK
THIS DECK COULD WORK ITS WAY WEST AND SOUTH ENOUGH TO AFFECT LBT
AND CRE RESPECTIVELY...BUT IT SHOULD BE JUST A TRANSITORY FEATURE.
SOME LIGHT FOG INLAND POSSIBLE...BUT WINDS ALOFT TOO STRONG TO
SUPPORT ANY HEAVY FOG. SATURDAY...CONTINUED NORTHEAST FLOW WITH A
VFR STRATA CU CEILING EXPECTED. THERE IS AN OUTSIDE CHANCE OF SOME
LIGHT PATCHY RAIN...BUT NOT ENOUGH TO PUT IN THE TAFS. CONTINUED
NORTHEAST FLOW WITH THICKENING AND LOWERING MID AND HIGH CLOUDS IN
ADVANCE OF THE NEXT SYSTEM TOWARD THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...VFR SATURDAY. SHOWERS AND LOW CEILINGS MOVE BACK
IN SATURDAY NIGHT THROUGH MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE CENTERED OVER KENTUCKY WILL BUILD
EAST OVER THE WATERS THRU THE NEAR TERM. PRESENT NORTHERLY FLOW OF
AROUND 15 KTS WILL VEER NORTHEAST THIS EVENING AS HIGH PRESSURE
BUILDS IN. GRADIENT WILL TIGHTEN UP OVERNIGHT AS HIGH BUILDS IN SO
COULD SEE WINDS INCREASE INTO THE 15 TO 20 KT RANGE...ESPECIALLY
NORTH OF CAPE FEAR...BY DAYBREAK SATURDAY. SEAS WILL BUILD INTO THE
3 TO 5 FT RANGE AS A RESULT...AGAIN...ESPECIALLY NORTH OF CAPE FEAR.
WILL HEADLINE OUR NC MARINE ZONES WITH SMALL CRAFT SHOULD EXERCISE
CAUTION BANNER FOR THIS EVENING AND OVERNIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...NORTHEAST FLOW SAT WILL INCREASE LATER IN THE
DAY AS GRADIENT BEGINS TO TIGHTEN BETWEEN HIGH PRESSURE TO THE NORTH
AND DEVELOPING GULF COAST LOW. CURRENT FORECAST DOES NOT CALL FOR
WINDS TO EXCEED SCA CRITERIA DURING THE PERIOD...BUT THERE REMAINS A
FAIR AMOUNT OF UNCERTAINTY. GULF COAST LOW WILL MOVE NORTHEAST SAT
NIGHT INTO SUN BUT TRACK OF LOW IS THE BIGGEST QUESTION. FAVORED
SCENARIO WOULD BE A SECONDARY LOW TO DEVELOP OFF THE SOUTHEAST
COAST. THIS LOW WOULD THEN MOVE NORTHEAST PASSING EAST OF THE WATERS
SUN INTO SUN NIGHT. ONCE THE LOW PASSES...NORTH TO NORTHEAST WINDS
BECOME OFFSHORE WITH A BRIEF DECREASE IN SPEEDS DURING THE SHIFT.
THINK SCA WILL BE NEEDED AT SOME POINT...LATER SAT OR SAT NIGHT BUT
NOT CONFIDENT ENOUGH TO RAISE IT JUST YET.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM SATURDAY...WEAK HIGH PRESSURE WILL BUILD IN BEHIND
DEPARTING STORM SYSTEM THROUGH TUES. OFF SHORE FLOW BECOMES
NORTHERLY BUT REMAINS VERY LIGHT LIGHT...10 KTS OR LESS THROUGH MUCH
OF PERIOD. SEAS ON A DECREASING TREND THROUGH MON STARTING AROUND
2-4 FT IN THE MORNING AND ENDING AROUND 3 FT BY MON NIGHT. SEAS WILL
REMAIN LOW IN A LIGHT NORTHERLY FLOW THROUGH WED. WITH DEVELOPMENT
OF COASTAL TROUGH HEADING INTO WED NIGHT...SHOULD SEE GRADIENT
TIGHTEN WITH WINDS BECOMING MORE ON SHORE AND SEAS INCREASING BY END
OF PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK
SHORT TERM...III
LONG TERM...RGZ
AVIATION...43
000
FXUS62 KMHX 202148
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
448 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH THROUGH SATURDAY...
THEN SLIDE OFFSHORE SATURDAY NIGHT. LOW PRESSURE WILL APPROACH
FROM THE SOUTHWEST SUNDAY AND MOVE NORTHEAST JUST OFFSHORE OF
THE COAST SUNDAY NIGHT INTO MONDAY. HIGH PRESSURE WILL REBUILD
OVER THE AREA TUESDAY AND WEDNESDAY. A COLD FRONT APPROACHES
FROM THE WEST ON THURSDAY THE MOVES OFFSHORE FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
STUBBORN LOW CLOUDINESS WILL GRADUALLY GIVE WAY TO CLEARING SKIES
AS ATMOS DRIES OUT FROM THE TOP DOWN TONIGHT BUT MAY LINGER THRU
MUCH OF THE OVERNIGHT ALONG THE COAST AS MOIST LOW LEVEL FLOW
CONTS. THERE MAY BE A SHARP LOW TEMPERATURE GRADIENT GIVEN THE
DIFF IN CLOUD COVER AND ONSHORE FLOW.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
HIGHS SAT WITH PLENTY OF SUN SHLD REACH THE LOW TO MID 60S. AS
HIGH MOVES OFFSHORE TO THE N SAT NIGHT WILL SEE INCREASING
MOISTURE AS LOW LVL FLOW BECOMES MORE ONSHORE. OVERALL ATMS IS DRY
TO START SO NOT LOOKING FOR MUCH RAIN TO DEVELOP SAT
NIGHT...MAINLY LATE NEAR THE COAST. APPROACHING SRT WAVE COMBINED
WITH INCREASING ISENT LIFT SHLD LEAD TO DECENT CVRG OF RAIN SUNDAY
INTO SUNDAY NIGHT. FOR NOW WILL LEAN MORE TWRD NAM/ECMWF KEEPING
MAINLY NE FLOW OVER THE REGION WITH LOW PRES NEAR OR JUST OFF THE
CST LATER SUN INTO MON. THIS WILL ALSO KEEP RAIN THREAT GOING
LONGER THAN PREV FCST INDICATED SO INCREASED POPS TO LIKELY SUN
NIGHT ALL AREAS AND CONT LIKELY INTO MON ESP OVER THE ERN HALF OF
THE AREA. CLOUDS AND PRECIP WILL LIMIT HIGHS TO UPPER 50S TO LOW
60S SUNDAY AND LOWER TO MID 60S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 230 AM FRIDAY...HIGH PRES WILL BUILD IN TUE AND WED WITH
DRY WEATHER. STRONG SHORT WAVE WILL APPROACH THE AREA ON
THANKSGIVING AND WILL INTRODUCE LOW CHC POPS FOR NOW.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
NLY FLOW CONTINUES ACROSS RTES TONIGHT. EXTENSIVE LOW CLOUDS
CONTINUE ACROSS ERN NC THIS EVENING BRINGING MVFR CIGS MOST
LOCATIONS TO IFR CIGS ACROSS SRN RTES. CIGS SLOWLY RISE LATE THIS
AFTERNOON WITH DRIER AIR FILTERING INTO THE REGION. VIS SATELLITE
SHOWING CLEARING TO THE NORTH AND WEST AND EXPECT IMPROVING
CONDITIONS ACROSS THE COASTAL PLAIN EARLY THIS EVENING HOWEVER ERN
RTES WILL LIKELY HANG ONTO LOWER CIGS...MAINLY MVFR....THROUGH
MOST OF THE EVENING AND POSSIBLY AFTER MIDNIGHT BEFORE CLEARING.
VFR SAT-SUN WITH HIGH PRES EXTENDING IN...THEN CONDITIONS
LOWERING SUN NIGHT-MON WITH LOW PRES MOVING ACROSS. CONDITIONS
IMPROVING AGAIN MON NIGHT-TUE WITH HIGH PRES AGAIN.
&&
.MARINE...
NORTHERLY SURGE CONTINUING TO BRING WINDS AROUND 20 TO 25 KT
ACROSS MOST OF THE WATERS LATE THIS AFTERNOON. WINDS BEGINNING TO
DIMINISH TO THE NORTH AND EXPECT WINDS TO CONTINUE TO GRADUALLY
DIMINISH FROM N TO S LATE THIS EVENING AND OVERNIGHT. SEAS UP TO 7
FT TO CONTINUE FROM DIAMOND SHOALS NWD AND UP TO 6 FT ACROSS THE
SRN COASTAL WATERS...ESPECIALLY OUTER WATERS. SEAS WILL ALSO
GRADUALLY SUBSIDE SAT AND SAT EVENING AND A PERIOD OF SUB SCA
CONDITIONS EXPECTED LATE SAT NIGHT EARLY SUN BEFORE THE NEXT
SYSTEM APPROACHES THE COASTAL WATERS.
LOW CONFIDENCE CONTINUES WITH NEXT LOW PRES SYSTEM AFFECTING AREA
LATE SUN INTO MON AND DID NOT MAKE SIGNIFICANT CHANGE TO PREVIOUS
FCST...KEEPING LOW TRACK OFFSHORE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 4 PM EST SATURDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY UNTIL 10 AM EST SATURDAY FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...BTC
SHORT TERM...BTC/RF
LONG TERM...BTC/RF
AVIATION...SK
MARINE...SK
000
FXUS62 KMHX 202117
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
417 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE NORTH THROUGH SATURDAY...
THEN SLIDE OFFSHORE SATURDAY NIGHT. LOW PRESSURE WILL APPROACH
FROM THE SOUTHWEST SUNDAY AND MOVE NORTHEAST JUST OFFSHORE OF
THE COAST SUNDAY NIGHT INTO MONDAY. HIGH PRESSURE WILL REBUILD
OVER THE AREA TUESDAY AND WEDNESDAY. A COLD FRONT APPROACHES
FROM THE WEST ON THURSDAY THE MOVES OFFSHORE FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
STUBBORN LOW CLOUDINESS WILL GRADUALLY GIVE WAY TO CLEARING SKIES
AS ATMOS DRIES OUT FROM THE TOP DOWN TONIGHT BUT MAY LINGER THRU
MUCH OF THE OVERNIGHT ALONG THE COAST AS MOIST LOW LEVEL FLOW
CONTS. THERE MAY BE A SHARP LOW TEMPERATURE GRADIENT GIVEN THE
DIFF IN CLOUD COVER AND ONSHORE FLOW.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
HIGHS SAT WITH PLENTY OF SUN SHLD REACH THE LOW TO MID 60S. AS
HIGH MOVES OFFSHORE TO THE N SAT NIGHT WILL SEE INCREASING
MOISTURE AS LOW LVL FLOW BECOMES MORE ONSHORE. OVERALL ATMS IS DRY
TO START SO NOT LOOKING FOR MUCH RAIN TO DEVELOP SAT
NIGHT...MAINLY LATE NEAR THE COAST. APPROACHING SRT WAVE COMBINED
WITH INCREASING ISENT LIFT SHLD LEAD TO DECENT CVRG OF RAIN SUNDAY
INTO SUNDAY NIGHT. FOR NOW WILL LEAN MORE TWRD NAM/ECMWF KEEPING
MAINLY NE FLOW OVER THE REGION WITH LOW PRES NEAR OR JUST OFF THE
CST LATER SUN INTO MON. THIS WILL ALSO KEEP RAIN THREAT GOING
LONGER THAN PREV FCST INDICATED SO INCREASED POPS TO LIKELY SUN
NIGHT ALL AREAS AND CONT LIKELY INTO MON ESP OVER THE ERN HALF OF
THE AREA. CLOUDS AND PRECIP WILL LIMIT HIGHS TO UPPER 50S TO LOW
60S SUNDAY AND LOWER TO MID 60S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 230 AM FRIDAY...HIGH PRES WILL BUILD IN TUE AND WED WITH
DRY WEATHER. STRONG SHORT WAVE WILL APPROACH THE AREA ON
THANKSGIVING AND WILL INTRODUCE LOW CHC POPS FOR NOW.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
EXPECT REDUCED CIGS TO IMPACT RTES THROUGH TODAY. GUIDANCE
SUGGESTING CLEARING INLAND THIS EVENING BUT ONLY SLOW CLEARING
ACROSS ERN RTES THROUGH THE OVERNIGHT.
VFR SAT-SUN WITH HIGH PRES EXTENDING IN...THEN CONDITIONS
LOWERING SUN NIGHT-MON WITH LOW PRES MOVING ACROSS. CONDITIONS
IMPROVING AGAIN MON NIGHT-TUE WITH HIGH PRES AGAIN.
&&
.MARINE...
WINDS AROUND 20 TO 25 KT CAN BE EXPECTED FOR THE REMAINDER OF THE
AFTERNOON WITH WINDS GRADUALLY DIMINISHING TONIGHT. SEAS REMAIN
AROUND 5 TO 6 FT ACROSS MOST WATERS...A BIT LOWER NEARSHORE SRN
WATERS WITH OFFSHORE FLOW...BUT WILL LIKELY BUILD A FOOT OR TWO
NRN AND OUTER SRN WATERS THIS AFTERNOON WITH INCREASED WINDS. HAVE
RAISED AND SC EXCERCISE CAUTION FOR THE SOUNDS WITH WINDS AROUND
20 KT WITH HIGHER GUSTS EXPECTED AND SCA CONTINUES FOR REMAINING
WATERS.
MODERATE NE WINDS AND HIGHER SEAS WILL PERSIST TONIGHT INTO SAT. LOW
CONFIDENCE FCST WITH NEXT LOW PRES SYSTEM AFFECTING AREA LATE SUN
INTO MON AND DID NOT MAKE SIGNIFICANT CHANGE TO PREVIOUS
FCST...KEEPING LOW TRACK OFFSHORE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 4 PM EST SATURDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY UNTIL 10 AM EST SATURDAY FOR AMZ150.
&&
$$
SYNOPSIS...BTC
NEAR TERM...BTC
SHORT TERM...BTC/RF
LONG TERM...BTC/RF
AVIATION...
MARINE...
000
FXUS62 KRAH 202018
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
315 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO CENTRAL NORTH CAROLINA FROM THE
NORTHWEST THROUGH TONIGHT. THE HIGH WILL DRIFT TO OUR NORTHEAST ON
SATURDAY... IN ADVANCE OF THE NEXT STORM SYSTEM WHICH WILL MOVE INTO
THE REGION FROM THE SOUTHWEST AND BRING CLOUDS AND RAIN FOR SUNDAY
AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1235 PM FRIDAY...
FOR THE REST OF TODAY THROUGH TONIGHT: THE LATEST SURFACE ANALYSIS
DEPICTS THE FRONT JUST OFF THE OUTER BANKS WITH THE INCOMING SURFACE
HIGH CENTERED OVER EASTERN KY. A DRY AND SUBSIDING COLUMN SHOULD
KEEP MOST AREAS RELATIVELY FREE FROM CLOUDS THROUGH THIS EVENING.
THE EXCEPTION IS OVER NORTHEAST NC WHERE A SURGE OF MOISTURE JUST
OFF THE SURFACE... NOTED WELL ON THE 12Z 925 MB ANALYSIS AND VISIBLE
SATELLITE IMAGERY... CONTINUES MOVING TOWARD THE SOUTH-SOUTHWEST
JUST AHEAD OF A SECONDARY LOW LEVEL COLD FRONT. THE 12Z/20 12KM NAM
SHOWED THIS FEATURE QUITE WELL... AND FAVORS PARTLY TO MOSTLY CLOUDY
SKIES SPREADING TO THE SOUTH-SOUTHWEST OVER EASTERN NC THROUGH THE
REST OF THIS AFTERNOON. FACTORING IN LOW LEVEL THICKNESSES... THE
CLOUDS IN THE EASTERN CWA... AND MOSTLY SUNNY SKIES ELSEWHERE...
STILL EXPECT HIGHS IN THE MID-UPPER 60S... COOLEST ACROSS THE NORTH
WHERE THE COLD AIR ADVECTION IS MOST PROFOUND. BEHIND THE SURGE OF
LOW LEVEL MOISTURE... SKIES SHOULD BE LARGELY CLOUD-FREE
OVERNIGHT... HOWEVER AS THE SURFACE HIGH SHIFTS UP INTO WV...
SURFACE WINDS IN NC SHOULD BECOME UNIFORM NORTHEASTERLY... AND GIVEN
THE MINOR AMOUNT OF RESIDUAL LOW LEVEL MOISTURE... THE UPSLOPE FLOW
AND RESULTANT LIFT/CONDENSATION COULD LEAD TO POCKETS OF STRATUS IN
THE EXTREME WESTERN CWA LATE TONIGHT. HIGH THIN CLOUDS BLOWING OFF
OF THE GULF COAST CONVECTION... ASSOCIATED WITH OUR NEXT STORM
SYSTEM... WILL START TO SPREAD SOUTHWEST TO NORTHEAST ACROSS THE
STATE LATE TONIGHT AS WELL. UNDER GENERALLY FAIR SKIES... STILL
EXPECT LOWS OF 39-46.
FOR SATURDAY: THE MID LEVEL VORTEX DEEPENING OVER EASTERN TX/OK THIS
AFTERNOON MOVES SLOWLY ACROSS LA/MS THROUGH SATURDAY. MID-UPPER
LEVEL MOISTURE STEADILY INCREASES AND DEEPENS OVER NC... WHILE THE
SURFACE HIGH TO OUR NORTH CONTINUES MOVING NORTHWARD TO A POSITION
OVER LAKE ERIE... WHERE IT BEGINS TO BE SUPPORTED BY CONFLUENT FLOW
ALOFT WITH NORTHERN STREAM SHORTWAVE TROUGHING OVER PA... CAUSING
THE HIGH TO GRADUALLY STRENGTHEN. THIS PATTERN SHOULD ENSURE A
STEADY NORTHEASTERLY FEED OF LOW LEVEL DRY AIR INTO CENTRAL NC...
SETTING US UP FOR DAMMING ONCE THE SURFACE HIGH CAN GET INTO A MORE
FAVORABLE POSITION (OVER THE ST LAWRENCE VALLEY) SATURDAY NIGHT
WHERE IT CAN TAP INTO EVEN COOLER AIR AND STRENGTHEN FURTHER WITH
THE SUPPORT ALOFT PERSISTING. EXPECT STEADILY LOWERING AND
THICKENING CLOUDS THROUGH THE DAY... WITH A FEW LOWER STRATOCUMULUS
OVER THE WESTERN PIEDMONT WITHIN EASTERLY UPSLOPE LOW LEVEL FLOW.
BUT THE MOST ACTION WITH THIS SYSTEM ON SATURDAY WILL BE BANDS OF
CONVECTION OVER AL/GA AND THE NORTHEAST GULF... AND ANY SIGNIFICANT
FORCING TO GENERATE PRECIP OVER NC HOLDS OFF UNTIL AFTER SUNDOWN
SATURDAY WITH NO DISCERNIBLE ISENTROPIC UPGLIDE AND UPPER DIVERGENCE
HOLDING TO OUR SOUTH THROUGH THE DAY... PLUS THE SUBCLOUD LAYER AT
1-3 KM OVER NC REMAINS RATHER DRY. HIGHS 60-65 ARE SUPPORTED BY LOW
LEVEL THICKNESS TRENDS AND ARE NEAR THE LATEST STATISTICAL GUIDANCE.
-GIH
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 315 PM FRIDAY...
THIS PORTION OF THE FORECAST WILL BE DRIVEN BY 1) A STRENGTHENING
(TO NEAR 1028-1034 MB) BUT MIGRATORY CAD SURFACE HIGH... 2) THE
APPROACH OF A DEAMPLIFYING BUT POWERFUL AND COMPLEX SOUTHERN STREAM
TROUGH ALOFT AND ATTENDANT UPPER JET LEFT EXIT REGION.... 3)
CYCLOGENESIS ALONG THE LOW LEVEL BAROCLINIC ZONE OFFSHORE THE EAST
COAST SOUTHWESTWARD INTO THE WESTERN GULF OF MEXICO... AND 4)
RESULTANT ISENTROPIC LIFT ATOP THE COLD DOME OVER INTERIOR NC.
THE OPERATIONAL MODELS ARE ALL OVER THE PLACE REGARDING THE
EVOLUTION OF THESE FEATURES AND RESULTANT TIMING OF THE UPCOMING
POTENTIAL RAIN EVENT OF AROUND A THIRD TO ONE INCH... HIGHLIGHTED BY
A FAST AND HEAVY OVER-THE-WESTERN PIEDMONT GFS LATE SATURDAY
NIGHT... AND THE TOTALLY DRY NAM FROM THE TRIANGLE NORTHWARD THROUGH
THE ENTIRE DAY SUNDAY. FORECAST CONFIDENCE IS ACCORDINGLY RELATIVELY
LOW... BUT WE WILL CONTINUE TO FAVOR THE TIMING OF THE PREVIOUS
FORECAST -- MOST CLOSELY RESEMBLING THE 12Z GEM -- WITH THE BULK OF
THE RAINFALL SUNDAY MORNING OVER THE SOUTHWEST... AND AREA WIDE BY
SUNDAY AFTERNOON AND SUNDAY NIGHT. FORECAST MAX TEMPERATURES SUNDAY
IN THE UPPER 40S NORTHWEST TO UPPER 50S SOUTHEAST COULD BE A FEW
DEGREES TOO COOL (ESPECIALLY ACROSS THE NORTHERN AND EASTERN PORTION
OF THE CWA)... GIVEN THE AFOREMENTIONED TIMING OF THE PRECIPITATION
SHIELD.
ALTHOUGH THE BULK OF THE PRECIPITATION SHOULD BE WINDING DOWN AND
LIFTING NORTHEASTWARD WITH THE COASTAL LOW... LOW CLOUDS AND DRIZZLE
IN NORTH OR NORTHEASTERLY LOW LEVEL FLOW ARE APT TO CONTINUE
THROUGHOUT THE DAY MONDAY (AND PERHAPS INTO MONDAY NIGHT). HAVE
ACCORDINGLY REDUCED HIGH TEMPERATURES BY 4 TO 8 DEGREES INTO THE 56
TO 63 DEGREE RANGE FROM NORTH TO SOUTH.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 105 PM FRIDAY...
TUESDAY THROUGH WEDNESDAY: ELONGATED SOUTHWEST TO NORTHEAST SURFACE
RIDGING... BENEATH BUILDING HEIGHTS IN SOUTHWESTERLY FLOW ALOFT
(AHEAD OF AN EVOLVING CENTRAL AND EVENTUALLY EASTERN CONUS
TROUGH)... SHOULD YIELD DRY AND ABOVE AVERAGE TEMPERATURES. HIGHS 62
TO 69... WARMEST TUESDAY. LOWS WITHIN A FEW DEGREES OF 45.
WEDNESDAY NIGHT THROUGH FRIDAY: A SERIES OF INTENSE SHORTWAVE
TROUGHS ALOFT WILL HELP AMPLIFY THE AFOREMENTIONED UPPER TROUGH
ACROSS THE GREAT LAKES AND INTO THE NORTHEAST THROUGH THE REMAINDER
OF THE PERIOD. CYCLOGENESIS SHOULD ENSUE OFF THE EAST COAST... AS
THE UPPER FORCING APPROACHES THE BAROCLINIC ZONE JUST OFFSHORE.
ACCORDINGLY EXPECT PRECIPITATION CHANCES TO REMAIN SUPPRESSED TO THE
EAST OF CENTRAL NC... THOUGH THERE PROBABLY WILL BE PERIODS OF MID
AND HIGH CLOUDS ASSOCIATED WITH THE APPROACHING UPPER TROUGH/JET
AXIS... PARTICULARLY OVER THE EASTERN HALF OF THE STATE.
TEMPERATURES TREND DOWNWARD AS THE L/W TROUGH AXIS SETTLES IN BY
FRIDAY. HIGHS 60 TO 65 THURSDAY... WITH LOWER TO MIDDLE 50S EXPECTED
FOR FRIDAY. LOWS INTO THE 30S THURSDAY AND FRIDAY NIGHTS.
&&
.AVIATION /17Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1215 PM FRIDAY...
VFR CONDITIONS WITH UNRESTRICTED CIGS AND VSBYS ARE EXPECTED AT
INT/GSO/RDU/FAY THROUGH TONIGHT... HOWEVER AT RWI... MVFR CONDITIONS
WILL CONTINUE THROUGH MUCH OF THE AFTERNOON. THIS STRATUS IS
ASSOCIATED WITH A SECONDARY FRONT LOCATED A COUPLE THOUSAND FEET OFF
THE SURFACE OVER NORTHEAST NC DROPPING TOWARD THE SOUTH-SOUTHWEST.
SCATTERED MVFR-LEVEL CLOUDS MAY DRIFT NEAR RDU AND FAY THIS
AFTERNOON BUT ARE NOT EXPECTED TO BECOME BROKEN. OTHERWISE... NORTH
TO NORTHEAST WINDS SUSTAINED NEAR 10 KTS MAY PERIODICALLY GUST TO
15-18 KTS THROUGH 21Z. AFTER 21Z... AS THE SURFACE HIGH BUILDS IN
FROM THE NORTHWEST... THE PRESSURE GRADIENT OVER THE AREA WILL RELAX
RESULTING IN SUBSIDING WINDS. SKIES ARE EXPECTED TO BE MOSTLY CLEAR
AFTER SUNDOWN WITH UNRESTRICTED VSBYS AND NO CIGS... ALTHOUGH
SCATTERED CLOUDS AT 2 KFT TO 3 KFT ARE POSSIBLE AT INT/GSO AFTER
MIDNIGHT THROUGH DAYBREAK WITH WEAK UPSLOPE FLOW IN THE LOW LEVELS.
OTHERWISE CLOUD BASES SHOULD HOLD ABOVE 14 KFT THROUGH EARLY
SATURDAY AFTERNOON.
LOOKING BEYOND MIDDAY SATURDAY: A STORM SYSTEM WILL APPROACH FROM
THE SOUTHWEST SATURDAY NIGHT/SUNDAY MORNING AND MAY BRING MVFR OR
IFR CONDITIONS TO THE REGION FOR SUNDAY THROUGH MONDAY. LOW CIGS ARE
EXPECTED TO CLEAR OUT BY MONDAY EVENING BUT AREAS OF IFR/LIFR FOG
MAY DEVELOP LATE MONDAY NIGHT/TUESDAY MORNING. VFR CONDITIONS ARE
ANTICIPATED TUESDAY MORNING THROUGH WEDNESDAY WITH HIGH PRESSURE
BUILDING IN FROM THE SOUTHWEST. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...MWS
LONG TERM...MWS
AVIATION...HARTFIELD
000
FXUS62 KILM 202018
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
318 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHWEST TODAY
AND SATURDAY. LOW PRESSURE EMERGING FROM THE GULF OF MEXICO WILL
BRING RAIN TO THE EASTERN CAROLINAS SUNDAY THROUGH EARLY
MONDAY...PULLING AWAY TO THE NORTHEAST BY MONDAY AFTERNOON. MILD
WEATHER CONDITIONS CAN BE EXPECTED MUCH OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 3 PM FRIDAY...HIGH PRESSURE CENTERED OVER KENTUCKY WILL BUILD
EAST OVER THE FORECAST AREA THRU THE NEAR TERM. PRESENT NORTHERLY
FLOW OF AROUND 10 KTS WILL VEER NORTHEAST THIS EVENING AS HIGH
PRESSURE BUILDS IN. DO NOT EXPECT WINDS TO DECOUPLE AS GRADIENT WILL
TIGHTEN UP OVERNIGHT AND WILL MAINTAIN A NORTHEASTERLY BREEZE OF
RIGHT AROUND 5 KTS. TIME HEIGHT CROSS SECTIONS AND SATELLITE LOOPS
INDICATE INCREASING CIRRUS MOVING IN OVERNIGHT. OTHERWISE...LOWER
AND MID LEVELS WILL REMAIN VERY DRY AND STABLE OVERNIGHT WITH NO
CHANCE OF PRECIPITATION. QUITE A BIT OF CLOUD COVER AT AROUND 5
THOUSAND FEET IS NOW ADVECTING DOWN THE COAST IN THE NORTHERLY FLOW.
THESE CLOUDS ARE THINNING OUT AS THEY ARE MOVING IN SO DO NOT EXPECT
COMPLETELY OVERCAST ALTHOUGH OUR NC COASTAL COUNTIES WILL SEE BROKEN
SKIES AT TIMES. MODEL CONSENSUS HAS OVERNIGHT TEMPS REMAINING A TAD
ABOVE NORMAL...FROM MID 40S INLAND TO AROUND 50 AT THE BEACHES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE BUILDING IN FROM THE NORTH WILL
KEEP THE FORECAST AREA DRY ON SAT. UPPER LEVEL MOISTURE ADVECTION
AHEAD OF DEVELOPING GULF COAST STORM WILL RESULT IN A LOT OF MID AND
UPPER LEVEL CLOUDS. ALONG THE COAST COOLER LOW LEVEL FLOW WILL
RESULT IN SOME LOW CU DEVELOPING...BUT WEAK SUBSIDENCE INVERSION
BETWEEN 850 AND 750 MB WILL PREVENT ANY PRECIP FROM FALLING. CLOUD
COVER AND NORTHERLY FLOW WILL KEEP TEMPERATURES A LITTLE COOLER THAN
FRI...RIGHT AROUND CLIMO.
CLOUD BASES LOWER SAT NIGHT INTO SUN WITH CROSS SECTIONS SHOWING THE
ATMOSPHERE BECOMING NEARLY SATURATED FROM THE SURFACE THROUGH 200 MB
AROUND MIDNIGHT WITH LIGHT RAIN DEVELOPING. BEST ISENTROPIC LIFT
ARRIVES SUN MORNING ACROSS SW PORTIONS...SPREADING OVER NE PARTS OF
THE FORECAST AREA BY NOON. CANNOT FIND ANY REASON TO NOT GO WITH
CATEGORICAL POPS ON SUN. BIG QUESTION IS HOW WILL THE SYSTEM EVOLVE
ONCE IT REACHES THE AREA. DO NOT LIKE THE LATEST NAM SOLUTION WHICH
TRACKS MAIN LOW WEST OF THE MOUNTAINS. THE FAVORED SOLUTION...AND
ONE SUPPORTED BY THE LATEST GFS/ECMWF/CANADIAN...TAKES THE LOW INTO
THE SOUTHEAST US AND DEVELOPS A SECONDARY LOW ALONG OR JUST OFF THE
COAST. STILL UNSURE EXACTLY WHERE THIS LOW WILL TRACK...BUT LIKE THE
ECMWF AND CANADIAN SOLUTION WITH THE LOW MOVE NORTHEAST JUST OFF THE
COAST. THIS WOULD KEEP THE ENTIRE AREA IN STRATIFORM PRECIP AND
COOLER NORTHERLY FLOW. HAVE TRENDED HIGHS DOWN TO ACCOUNT FOR
THIS...BUT THERE STILL REMAINS PLENTY OF POTENTIAL FOR THE FORECAST
TO GO AWRY. LOW PASSING OVER OR WEST OF THE AREA WOULD LEAD TO HIGH
TEMPS WHILE A LOW FARTHER OFFSHORE WILL RESULT IN MUCH COOLER TEMPS.
CLOUDS LINGER SUN NIGHT BUT PRECIP WILL BE ENDING AS THE SYSTEM
MOVES OFF TO THE NORTHEAST AND STARTS TO DEEPEN. NORTHERLY FLOW WILL
INCREASE WITH CLOUDS AND MIXING KEEPING LOWS WELL ABOVE CLIMO.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM SATURDAY...WEAK HIGH PRESSURE WILL BUILD IN BEHIND COLD
FRONT MON THROUGH TUES...BUT GFS SHOWS WEAK SHORT WAVE CROSSING THE
AREA MON NIGHT. PCP WATER CLOSE TO AN INCH MON MORNING WILL DECREASE
THROUGH THE DAY REACHING DOWN TO AROUND A HALF INCH BY TUES. ANY
LINGERING PRECIP SHOULD EXIT THE AREA THROUGH MON MORNING. OVERALL
EXPECT VERY DRY MID LEVELS BUT MAY SEE SOME LOW CLOUDS AND DRIZZLE
HANGING AROUND THROUGH TUES MORNING. DRIER WESTERLY FLOW TAKES OVER
THROUGH MID WEEK. TUES NIGHT A COLD FRONT REACHES THE WRN
CAROLINAS...BUT BECOMES VERY DIFFUSE AFTER CROSSING THE MOUNTAINS
INTO THE COASTAL CAROLINAS. MAY NOT SEE MUCH IN THE WAY OF PCP AS
THE FRONT MOVES INTO LOCAL AREA...BUT BOUNDARY WILL REACH THE COAST
WHILE A COASTAL TROUGH BECOMES MORE PRONOUNCED HEADING INTO THURS.
PCP WATER INCREASES BUT MAY BE MORE IN THE WAY OF UPPER LEVEL
MOISTURE IN HIGH CLOUDS IN W-SW JET. GFS KEEPS THIS PCP OFF
SHORE...BUT TOO CLOSE FOR COMFORT AND MAY SEE A WETTER FORECAST FOR
THANKSGIVING DAY...ESPECIALLY ALONG THE COAST. WITH BOUNDARY SO
CLOSE AND FORECAST SO OUT IN TIME...WILL KEEP SOME LOW END POPS IN
FORECAST FOR NOW ESPECIALLY CLOSE TO THE COAST. BY FRI HIGH
AMPLITUDE MID TO UPPER TROUGH SWINGS ACROSS THE EAST COAST SCOURING
OUT ALL THE WEATHER AND BRINGING DRY AND COOL HIGH PRESSURE FOR THE
WEEKEND. DEEP LAYER NW FLOW ADVECTS PLENTY OF DRY AIR IN FOR FRI
WITH PCP WATER DOWN TO A QUARTER INCH OR LESS.
TEMPS WILL HOLD AROUND NORMAL OR ABOVE THROUGH MUCH OF THE WEEK
UNTIL FRI WHEN COLD AND DRY HIGH PRESSURE BUILDS IN.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
STRATUS HAS BROKEN AT ALL TERMINALS CREATING ONLY SCT 4K TO 5K FOOT
STRATOCU CEILINGS THIS AFTN. WINDS HAVE INCREASED TO 8 TO 15 KT
ACROSS THE REGION AS SUNSHINE HAS PROMOTED MIXING. LATEST SATELLITE
SHOWING EXPANDING STRATOCU DECK JUST OFFSHORE ILM...SO SOME BKN 4K
FOOT CIGS ARE POSSIBLE THERE AS NE FLOW PUSHES THIS TOWARDS SHORE.
TONIGHT...MOSTLY A CLEAR NIGHT AS WINDS SHOULD KEEP THINGS
MIXED...ESPECIALLY AT THE COASTAL TERMINALS. CANNOT ENTIRELY RULE
OUT SOME LIGHT FOG AT LBT/FLO IF WINDS DECOUPLE...BUT ANY FOG WILL
BE MUCH LESS DENSE THAN PREVIOUS TWO NIGHTS. TOMORROW...SIMILAR
CONDITIONS TO TODAY WITH NE FLOW 5 TO 10 KT. HOWEVER...SOME CIGS
AROUND 4K FEET MAY AGAIN DEVELOP AT THE COASTAL TERMINALS AS DEBRIS
FROM CONVECTION TRIES TO MOVE ONSHORE. BELIEVE BKN CIGS AT
MYR/CRE/ILM ARE WARRANTED IN THE TAFS DUE TO GUIDANCE CONSENSUS WITH
THIS FEATURE. INLAND...SOME 4K FOOT CIGS MAY ALSO DEVELOP VERY LATE
IN THE PERIOD BUT VFR WILL BE THE RULE TOMORROW AT ALL TERMINALS.
EXTENDED OUTLOOK...VFR SATURDAY. SHOWERS AND LOW CEILINGS MOVE BACK
IN SATURDAY NIGHT THROUGH MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...HIGH PRESSURE CENTERED OVER KENTUCKY WILL BUILD
EAST OVER THE WATERS THRU THE NEAR TERM. PRESENT NORTHERLY FLOW OF
AROUND 15 KTS WILL VEER NORTHEAST THIS EVENING AS HIGH PRESSURE
BUILDS IN. GRADIENT WILL TIGHTEN UP OVERNIGHT AS HIGH BUILDS IN SO
COULD SEE WINDS INCREASE INTO THE 15 TO 20 KT RANGE...ESPECIALLY
NORTH OF CAPE FEAR...BY DAYBREAK SATURDAY. SEAS WILL BUILD INTO THE
3 TO 5 FT RANGE AS A RESULT...AGAIN...ESPECIALLY NORTH OF CAPE FEAR.
WILL HEADLINE OUR NC MARINE ZONES WITH SMALL CRAFT SHOULD EXERCISE
CAUTION BANNER FOR THIS EVENING AND OVERNIGHT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...NORTHEAST FLOW SAT WILL INCREASE LATER IN THE
DAY AS GRADIENT BEGINS TO TIGHTEN BETWEEN HIGH PRESSURE TO THE NORTH
AND DEVELOPING GULF COAST LOW. CURRENT FORECAST DOES NOT CALL FOR
WINDS TO EXCEED SCA CRITERIA DURING THE PERIOD...BUT THERE REMAINS A
FAIR AMOUNT OF UNCERTAINTY. GULF COAST LOW WILL MOVE NORTHEAST SAT
NIGHT INTO SUN BUT TRACK OF LOW IS THE BIGGEST QUESTION. FAVORED
SCENARIO WOULD BE A SECONDARY LOW TO DEVELOP OFF THE SOUTHEAST
COAST. THIS LOW WOULD THEN MOVE NORTHEAST PASSING EAST OF THE WATERS
SUN INTO SUN NIGHT. ONCE THE LOW PASSES...NORTH TO NORTHEAST WINDS
BECOME OFFSHORE WITH A BRIEF DECREASE IN SPEEDS DURING THE SHIFT.
THINK SCA WILL BE NEEDED AT SOME POINT...LATER SAT OR SAT NIGHT BUT
NOT CONFIDENT ENOUGH TO RAISE IT JUST YET.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM SATURDAY...WEAK HIGH PRESSURE WILL BUILD IN BEHIND
DEPARTING STORM SYSTEM THROUGH TUES. OFF SHORE FLOW BECOMES
NORTHERLY BUT REMAINS VERY LIGHT LIGHT...10 KTS OR LESS THROUGH MUCH
OF PERIOD. SEAS ON A DECREASING TREND THROUGH MON STARTING AROUND
2-4 FT IN THE MORNING AND ENDING AROUND 3 FT BY MON NIGHT. SEAS WILL
REMAIN LOW IN A LIGHT NORTHERLY FLOW THROUGH WED. WITH DEVELOPMENT
OF COASTAL TROUGH HEADING INTO WED NIGHT...SHOULD SEE GRADIENT
TIGHTEN WITH WINDS BECOMING MORE ON SHORE AND SEAS INCREASING BY END
OF PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...REK
SHORT TERM...III
LONG TERM...RGZ
AVIATION...JDW
000
FXUS62 KRAH 201811
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
110 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO CENTRAL NORTH CAROLINA FROM THE
NORTHWEST THROUGH TONIGHT. THE HIGH WILL DRIFT TO OUR NORTHEAST ON
SATURDAY... IN ADVANCE OF THE NEXT STORM SYSTEM WHICH WILL MOVE INTO
THE REGION FROM THE SOUTHWEST AND BRING CLOUDS AND RAIN FOR SUNDAY
AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1235 PM FRIDAY...
FOR THE REST OF TODAY THROUGH TONIGHT: THE LATEST SURFACE ANALYSIS
DEPICTS THE FRONT JUST OFF THE OUTER BANKS WITH THE INCOMING SURFACE
HIGH CENTERED OVER EASTERN KY. A DRY AND SUBSIDING COLUMN SHOULD
KEEP MOST AREAS RELATIVELY FREE FROM CLOUDS THROUGH THIS EVENING.
THE EXCEPTION IS OVER NORTHEAST NC WHERE A SURGE OF MOISTURE JUST
OFF THE SURFACE... NOTED WELL ON THE 12Z 925 MB ANALYSIS AND VISIBLE
SATELLITE IMAGERY... CONTINUES MOVING TOWARD THE SOUTH-SOUTHWEST
JUST AHEAD OF A SECONDARY LOW LEVEL COLD FRONT. THE 12Z/20 12KM NAM
SHOWED THIS FEATURE QUITE WELL... AND FAVORS PARTLY TO MOSTLY CLOUDY
SKIES SPREADING TO THE SOUTH-SOUTHWEST OVER EASTERN NC THROUGH THE
REST OF THIS AFTERNOON. FACTORING IN LOW LEVEL THICKNESSES... THE
CLOUDS IN THE EASTERN CWA... AND MOSTLY SUNNY SKIES ELSEWHERE...
STILL EXPECT HIGHS IN THE MID-UPPER 60S... COOLEST ACROSS THE NORTH
WHERE THE COLD AIR ADVECTION IS MOST PROFOUND. BEHIND THE SURGE OF
LOW LEVEL MOISTURE... SKIES SHOULD BE LARGELY CLOUD-FREE
OVERNIGHT... HOWEVER AS THE SURFACE HIGH SHIFTS UP INTO WV...
SURFACE WINDS IN NC SHOULD BECOME UNIFORM NORTHEASTERLY... AND GIVEN
THE MINOR AMOUNT OF RESIDUAL LOW LEVEL MOISTURE... THE UPSLOPE FLOW
AND RESULTANT LIFT/CONDENSATION COULD LEAD TO POCKETS OF STRATUS IN
THE EXTREME WESTERN CWA LATE TONIGHT. HIGH THIN CLOUDS BLOWING OFF
OF THE GULF COAST CONVECTION... ASSOCIATED WITH OUR NEXT STORM
SYSTEM... WILL START TO SPREAD SOUTHWEST TO NORTHEAST ACROSS THE
STATE LATE TONIGHT AS WELL. UNDER GENERALLY FAIR SKIES... STILL
EXPECT LOWS OF 39-46.
FOR SATURDAY: THE MID LEVEL VORTEX DEEPENING OVER EASTERN TX/OK THIS
AFTERNOON MOVES SLOWLY ACROSS LA/MS THROUGH SATURDAY. MID-UPPER
LEVEL MOISTURE STEADILY INCREASES AND DEEPENS OVER NC... WHILE THE
SURFACE HIGH TO OUR NORTH CONTINUES MOVING NORTHWARD TO A POSITION
OVER LAKE ERIE... WHERE IT BEGINS TO BE SUPPORTED BY CONFLUENT FLOW
ALOFT WITH NORTHERN STREAM SHORTWAVE TROUGHING OVER PA... CAUSING
THE HIGH TO GRADUALLY STRENGTHEN. THIS PATTERN SHOULD ENSURE A
STEADY NORTHEASTERLY FEED OF LOW LEVEL DRY AIR INTO CENTRAL NC...
SETTING US UP FOR DAMMING ONCE THE SURFACE HIGH CAN GET INTO A MORE
FAVORABLE POSITION (OVER THE ST LAWRENCE VALLEY) SATURDAY NIGHT
WHERE IT CAN TAP INTO EVEN COOLER AIR AND STRENGTHEN FURTHER WITH
THE SUPPORT ALOFT PERSISTING. EXPECT STEADILY LOWERING AND
THICKENING CLOUDS THROUGH THE DAY... WITH A FEW LOWER STRATOCUMULUS
OVER THE WESTERN PIEDMONT WITHIN EASTERLY UPSLOPE LOW LEVEL FLOW.
BUT THE MOST ACTION WITH THIS SYSTEM ON SATURDAY WILL BE BANDS OF
CONVECTION OVER AL/GA AND THE NORTHEAST GULF... AND ANY SIGNIFICANT
FORCING TO GENERATE PRECIP OVER NC HOLDS OFF UNTIL AFTER SUNDOWN
SATURDAY WITH NO DISCERNIBLE ISENTROPIC UPGLIDE AND UPPER DIVERGENCE
HOLDING TO OUR SOUTH THROUGH THE DAY... PLUS THE SUBCLOUD LAYER AT
1-3 KM OVER NC REMAINS RATHER DRY. HIGHS 60-65 ARE SUPPORTED BY LOW
LEVEL THICKNESS TRENDS AND ARE NEAR THE LATEST STATISTICAL GUIDANCE.
-GIH
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 315 AM FRIDAY...
SATURDAY NIGHT...925-850MB FLOW BACKS AND STRENGTHENS IN RESPONSE TO
APPROACH OF SOUTHERN STREAM LOW PRESSURE SYSTEM LIFTING ACROSS THE
LOWER MS VALLEY. EXPECT CLOUDS TO LOWER THICKEN. ISENTROPIC LIFT
INCREASES TOWARD 12Z IN THE 300-305 LAYER...MORE SO AFTER 12Z. WILL
MAINTAIN DRY CONDITIONS THROUGH 06Z..THEN MAINTAIN CONTINUE PREVIOUS
FORECAST OF INCREASING POPS SW-NE AFTER 06Z. REFRAINED FROM
INCREASING POPS ABOVE 40 PERCENT. RH PROFILES DEPICT RELATIVELY DRY
SUB CLOUD LAYER TILL 12Z SO INITIAL PRECIP WILL GO TOWARD MOISTENING
THIS LAYER. IF MOISTENING OCCURS FASTER THAN EXPECTED THEN COULD SEE
NEED TO INCREASE POPS TO LOW END LIKELY IN THE FAR W-SW. RAISED MIN
TEMPS A FEW DEGREES BASED ON THICKENING CLOUD COVERAGE IN THE WEST.
MIN TEMPS LOWER 40S NE TO MID/UPPER 40S WEST-SOUTH. -WSS
BY 12Z SUNDAY...A SOUTHERN STREAM SHORTWAVE TROUGH IS PROGGED TO
HAVE BECOME NEGATIVELY TILTED...LIFTING FROM THE GULF COAST INTO THE
TN VALLEY REGION. WITH A 1025MB HIGH OVER THE NY/CANADA
BORDER...AND A SURFACE LOW LIFTING NORTHEAST WITH THE
SHORTWAVE...MODELS HAVE BEEN SHOWING A MILLER B TYPE SURFACE
PRESSURE EVOLUTION FOR SUNDAY INTO SUNDAY NIGHT. AS THE SHORTWAVE
AND LOW LIFT NORTHEAST..AND A SOUTHERN STREAM JET IS PULLED
NORTHWARD...UPPER LEVEL DIFFLUENCE WILL INCREASE OVER CENTRAL
NC...AND COMBINED WITH STRENGTHENING 850MB FLOW AND LOW LEVEL WARM
ADVECTION...EXPECT RAIN CHANCES TO INCREASE RAPIDLY SUNDAY MORNING.
THERE ARE STILL SOME INCONSISTENCIES AMONG MODEL GUIDANCE ON THE
STRENGTH OF THE SHORTWAVE AS IT PASSES BY...AND ALSO ON THE TIMING
OF DEVELOPMENT AND MOVEMENT OF THE SECONDARY SURFACE LOW ALONG THE
COAST. THE SHORTWAVE IS EXPECTED TO BE SHEARING OUT AS IT LIFTS
THROUGH THE TN VALLEY REGION...AND THE NAM/GFS ARE STRONGER AND
FASTER THAN THE ECMWF OR CANADIAN...WHOSE LATEST RUNS HAVE COME IN
WITH A MORE MILLER TYPE A SURFACE LOW TRACK (POSSIBLY DUE TO A MORE
SOUTHWARD POSITION OF THE SURFACE HIGH TO OUR NORTH). QPF FORECAST
ALSO SUFFERS FROM THESE DIFFERENCES...BUT THERE SEEMS TO BE A
GENERAL TREND TOWARDS A SPLIT...WITH BEST COVERAGE INITIALLY WITH
THE UPPER WAVE AND ISENTROPIC LIFT IN THE WEST...SHIFTING TO THE
EAST AS THE SECONDARY LOW DEVELOPS OFF THE SAVANNAH COAST SUNDAY
NIGHT AND TRACKS NORTH SOMEWHERE ALONG THE COAST. FOR NOW...WILL
NOT MAKE MANY CHANGES TO THE CURRENT FORECAST...WITH POPS INCREASING
TO LIKELY AFTER 12Z SUNDAY...WITH THE HIGHEST POPS SHIFTING TO THE
EAST AFTER 00Z MONDAY. AS MENTIONED IN EARLIER DISCUSSIONS...THE
CURRENT FORECAST TRACK OF THE COASTAL LOW KEEPS THE CWA ON THE COOL
SIDE OF THE COASTAL FRONT AND THUS VOID OF ANY SURFACE BASED
CONVECTION. HIGHS SUNDAY WILL VARY WIDELY FROM THE COOL CAD AIRMASS
IN THE WEST WHERE MID TO UPPER 40S ARE POSSIBLE...TO WARMER UPPER
50S TO EVEN 60 IN THE SE.
MID LEVEL DRY AIR WILL BRING RAIN TO AN END FROM SW TO NE ON MONDAY
AS A SURFACE HIGH BUILDS ACROSS THE SE US AND WILL HAVE ALL POPS OUT
OF THE CWA BY 00Z TUESDAY. FORECAST LOW LEVEL THICKNESSES CLIMB
20-30M ON MONDAY WITH A WELL MODIFIED HIGH TAKING HOLD. A SLOWER
TRACK OF A COASTAL LOW COULD KEEP CLOUD COVER IN LONGER....A
REINFORCED NORTHERLY FLOW OVER THE AREA... AND HIGHS COOLER. PREFER
A BLEND OF GUIDANCE...59-66 NW-SE.
SURFACE HIGH PRESSURE RIDGE SETTLES OVER THE AREA TUESDAY MORNING
WHICH COULD LEAD TO FOG ISSUES DEPENDING ON ANTECEDENT RAINFALL.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 105 PM FRIDAY...
TUESDAY THROUGH WEDNESDAY: ELONGATED SOUTHWEST TO NORTHEAST SURFACE
RIDGING... BENEATH BUILDING HEIGHTS IN SOUTHWESTERLY FLOW ALOFT
(AHEAD OF AN EVOLVING CENTRAL AND EVENTUALLY EASTERN CONUS
TROUGH)... SHOULD YIELD DRY AND ABOVE AVERAGE TEMPERATURES. HIGHS 62
TO 69... WARMEST TUESDAY. LOWS WITHIN A FEW DEGREES OF 45.
WEDNESDAY NIGHT THROUGH FRIDAY: A SERIES OF INTENSE SHORTWAVE
TROUGHS ALOFT WILL HELP AMPLIFY THE AFOREMENTIONED UPPER TROUGH
ACROSS THE GREAT LAKES AND INTO THE NORTHEAST THROUGH THE REMAINDER
OF THE PERIOD. CYCLOGENESIS SHOULD ENSUE OFF THE EAST COAST... AS
THE UPPER FORCING APPROACHES THE BAROCLINIC ZONE JUST OFFSHORE.
ACCORDINGLY EXPECT PRECIPITATION CHANCES TO REMAIN SUPPRESSED TO THE
EAST OF CENTRAL NC... THOUGH THERE PROBABLY WILL BE PERIODS OF MID
AND HIGH CLOUDS ASSOCIATED WITH THE APPROACHING UPPER TROUGH/JET
AXIS... PARTICULARLY OVER THE EASTERN HALF OF THE STATE.
TEMPERATURES TREND DOWNWARD AS THE L/W TROUGH AXIS SETTLES IN BY
FRIDAY. HIGHS 60 TO 65 THURSDAY... WITH LOWER TO MIDDLE 50S EXPECTED
FOR FRIDAY. LOWS INTO THE 30S THURSDAY AND FRIDAY NIGHTS.
&&
.AVIATION /17Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1215 PM FRIDAY...
VFR CONDITIONS WITH UNRESTRICTED CIGS AND VSBYS ARE EXPECTED AT
INT/GSO/RDU/FAY THROUGH TONIGHT... HOWEVER AT RWI... MVFR CONDITIONS
WILL CONTINUE THROUGH MUCH OF THE AFTERNOON. THIS STRATUS IS
ASSOCIATED WITH A SECONDARY FRONT LOCATED A COUPLE THOUSAND FEET OFF
THE SURFACE OVER NORTHEAST NC DROPPING TOWARD THE SOUTH-SOUTHWEST.
SCATTERED MVFR-LEVEL CLOUDS MAY DRIFT NEAR RDU AND FAY THIS
AFTERNOON BUT ARE NOT EXPECTED TO BECOME BROKEN. OTHERWISE... NORTH
TO NORTHEAST WINDS SUSTAINED NEAR 10 KTS MAY PERIODICALLY GUST TO
15-18 KTS THROUGH 21Z. AFTER 21Z... AS THE SURFACE HIGH BUILDS IN
FROM THE NORTHWEST... THE PRESSURE GRADIENT OVER THE AREA WILL RELAX
RESULTING IN SUBSIDING WINDS. SKIES ARE EXPECTED TO BE MOSTLY CLEAR
AFTER SUNDOWN WITH UNRESTRICTED VSBYS AND NO CIGS... ALTHOUGH
SCATTERED CLOUDS AT 2 KFT TO 3 KFT ARE POSSIBLE AT INT/GSO AFTER
MIDNIGHT THROUGH DAYBREAK WITH WEAK UPSLOPE FLOW IN THE LOW LEVELS.
OTHERWISE CLOUD BASES SHOULD HOLD ABOVE 14 KFT THROUGH EARLY
SATURDAY AFTERNOON.
LOOKING BEYOND MIDDAY SATURDAY: A STORM SYSTEM WILL APPROACH FROM
THE SOUTHWEST SATURDAY NIGHT/SUNDAY MORNING AND MAY BRING MVFR OR
IFR CONDITIONS TO THE REGION FOR SUNDAY THROUGH MONDAY. LOW CIGS ARE
EXPECTED TO CLEAR OUT BY MONDAY EVENING BUT AREAS OF IFR/LIFR FOG
MAY DEVELOP LATE MONDAY NIGHT/TUESDAY MORNING. VFR CONDITIONS ARE
ANTICIPATED TUESDAY MORNING THROUGH WEDNESDAY WITH HIGH PRESSURE
BUILDING IN FROM THE SOUTHWEST. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...WSS/SMITH
LONG TERM...MWS
AVIATION...HARTFIELD
000
FXUS62 KILM 201737
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1237 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHWEST TODAY
AND SATURDAY. LOW PRESSURE EMERGING FROM THE GULF OF MEXICO WILL
BRING RAIN TO THE EASTERN CAROLINAS SUNDAY THROUGH EARLY
MONDAY...PULLING AWAY TO THE NORTHEAST BY MONDAY AFTERNOON. MILD
WEATHER CONDITIONS CAN BE EXPECTED MUCH OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM FRIDAY...NORTHERLY FLOW PICKING UP AS HIGH PRESSURE
PUSHES IN FROM THE WEST AND A COLD FRONT MOVES FURTHER OFFSHORE.
MODEL AND ACTUAL AREA SOUNDINGS AND WATER VAPOR PICS SHOW VERY DRY
AIR MOVING IN ALOFT. ANALYSIS OF MORNING DATA SHOWS TODAY WILL BE
A DRY AND STABLE ONE WITH PARTLY CLOUDY SKIES. PRESENT EXTENSIVE
AREA OF STRATUS IS BURNING OFF AS DAYTIME MIXING
COMMENCES...BRINGING DOWN THE DRYER AIR FROM ALOFT. ENOUGH LOW
LEVEL MOISTURE WILL REMAIN FOR SOME FLAT CU TO DEVELOP THIS
AFTERNOON UNDER A SUBSIDENCE INVERSION. SATELLITE AND MODEL CROSS
SECTIONS SUGGEST CIRRUS MOVING IN THE EVENING AND OVERNIGHT FROM
THE GULF COAST STATES. MAX TEMP TODAY RIGHT AROUND 70.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...WILL CONTINUE THE TREND OF SLOWING DOWN A
COMPLEX STORM SYSTEM THAT WILL LIFT OUT OF THE GULF THIS WEEKEND.
IT NOW APPEARS THAT THE CWA WILL REMAIN DRY FOR ALL OF SATURDAY
AND INTO SATURDAY EVENING. MAX TEMPS NEAR NORMAL FOR THIS TIME OF
YEAR...LIMITED MAINLY BY INCREASING HIGH CLOUDS AHEAD OF THE LOW
DEVELOPING ALONG THE GULF COAST.
LATEST NAM AND GFS ARE NOW DEPICTING MILLER TYPE-B CYCLOGENESIS AS
WE HEAD INTO SUNDAY...BUT AT THIS POINT THINK THE MAIN POINT IS
THAT IT WILL HAPPEN MORE SLOWLY. ENOUGH DRY AIR FROM 850-750MB
THAT IT WILL TAKE MOST OF SATURDAY NIGHT TO OVERCOME...SO HAVE
TAPERED POPS FROM HIGH CHANCE IN THE SOUTH TO LOW CHANCE IN THE
NORTH. WENT WITH LIKELY SUNDAY INTO SUNDAY NIGHT AS THE MOISTURE
FEED BECOMES WELL ESTABLISHED AROUND 12Z SUN...AND PERSISTS BEYOND
00Z MON. THERE IS CERTAINLY AN ARGUMENT TO BE MADE FOR A RAPID
SHUTOFF IN THE PRECIP SUN NIGHT...BUT NOT GETTING TOO CUTE WITH
THE TIMING THIS FAR OUT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...DRY WEATHER PATTERN IN STORE FOR THE
EXTENDED...WITH CHILLY AIR KNOCKING ON THE DOOR BY THE END. SFC
RIDGING ALONG THE GULF COAST AND A FLAT UPPER PATTERN WILL KEEP
TEMPS MILD...WITH HIGHS CLOSE TO 70 MON-WED AND LOWS ALSO A
CATEGORY OR TWO ABOVE CLIMO. BY THURSDAY LOOK FOR A FULL-LATITUDE
TROUGH TO SETTLE IN ALONG THE EAST COAST. HARD TO TIME THE
ASSOCIATED COLD FRONT...BUT REGARDLESS IT LOOKS TO BE MOISTURE-
STARVED...SO NO POPS WILL BE INCLUDED AT THIS TIME. DAYTIME TEMPS
NEAR NORMAL FOR TURKEY DAY...AS THE CHILLY AIR HOLDS OFF UNTIL
BEYOND THE VALID PERIOD OF THE ZONE FORECAST.
&&
.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
STRATUS HAS BROKEN AT ALL TERMINALS CREATING ONLY SCT 4K TO 5K FOOT
STRATOCU CEILINGS THIS AFTN. WINDS HAVE INCREASED TO 8 TO 15 KT
ACROSS THE REGION AS SUNSHINE HAS PROMOTED MIXING. LATEST SATELLITE
SHOWING EXPANDING STRATOCU DECK JUST OFFSHORE ILM...SO SOME BKN 4K
FOOT CIGS ARE POSSIBLE THERE AS NE FLOW PUSHES THIS TOWARDS SHORE.
TONIGHT...MOSTLY A CLEAR NIGHT AS WINDS SHOULD KEEP THINGS
MIXED...ESPECIALLY AT THE COASTAL TERMINALS. CANNOT ENTIRELY RULE
OUT SOME LIGHT FOG AT LBT/FLO IF WINDS DECOUPLE...BUT ANY FOG WILL
BE MUCH LESS DENSE THAN PREVIOUS TWO NIGHTS. TOMORROW...SIMILAR
CONDITIONS TO TODAY WITH NE FLOW 5 TO 10 KT. HOWEVER...SOME CIGS
AROUND 4K FEET MAY AGAIN DEVELOP AT THE COASTAL TERMINALS AS DEBRIS
FROM CONVECTION TRIES TO MOVE ONSHORE. BELIEVE BKN CIGS AT
MYR/CRE/ILM ARE WARRANTED IN THE TAFS DUE TO GUIDANCE CONSENSUS WITH
THIS FEATURE. INLAND...SOME 4K FOOT CIGS MAY ALSO DEVELOP VERY LATE
IN THE PERIOD BUT VFR WILL BE THE RULE TOMORROW AT ALL TERMINALS.
EXTENDED OUTLOOK...VFR SATURDAY. SHOWERS AND LOW CEILINGS MOVE BACK
IN SATURDAY NIGHT THROUGH MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM FRIDAY...NORTHERLY WINDS PICKING UP AS HIGH PRESSURE
PUSHES IN FROM THE WEST AND A COLD FRONT MOVES FURTHER EAST OF THE
WATERS. WINDS WILL VEER TO THE NE THIS EVENING AS HIGH PRESSURE
BUILDS FURTHER EAST. WINDS WILL BE RIGHT AROUND 15 KTS THRU THE
NEAR TERM...WITH SEAS STAYING IN THE 2 TO 4 FT RANGE.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...EXPECT STATUS QUO WITH NE WINDS SATURDAY AND
SATURDAY NIGHT. FOR NOW WILL KEEP SPEEDS AROUND 15 KT...BUT THE
GRADIENT APPEARS TO TIGHTEN BY SUNDAY MORNING. COULD SEE A SOLID
20 KT...AND THE NE FETCH WILL BE PERSISTENT ENOUGH TO GENERATE
SOME 6 FT SEAS ALONG FRYING PAN SHOALS AND OFF CAPE ROMAIN. NOT
NEARLY AS MUCH FETCH TO WORK WITH NEAR SHORE...SO LOOK FOR A MUCH
MORE MODEST 2-3 FT THERE.
SUNDAY NIGHT IS THE LOW CONFIDENCE PORTION OF THE FORECAST. LATEST
NAM AND GFS NOW TRY TO PULL THE LOW IN OVER LAND AS IT CROSSES
EASTERN NC. NOT SOLD ENOUGH ON THIS SOLUTION JUST YET...SO WILL
REMAIN CLOSE TO THE PREVIOUS FORECAST WHICH MAINTAINS AN OFFSHORE
TRACK. WILL BRING THE LOW CLOSE ENOUGH TO SEE A VEERING TO ENE
AHEAD OF IT...AND BACKING TO NW AS THE LOW DEPARTS. LOOK FOR A
DIMINISHING TREND IN WINDS DUE TO PROXIMITY OF THE LOW...AND SEAS
GENERALLY IN THE 3-4 FT RANGE FOR MUCH OF THE NIGHT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...WILL START OFF MONDAY WITH NW WINDS BEHIND
DEPARTING LOW PRESSURE. WITH THE HIGH BUILDING FROM THE GULF COAST
AND FLAT RIDGING ALOFT...WOULD NOT EXPECT ANY COLD AIR SURGE...SO
WIND SPEEDS WILL REMAIN QUITE TAME...AROUND 10 KT. COULD SEE WINDS
BACK AROUND TO WESTERLY ON TUESDAY AS THE SFC RIDGE IS SUPPRESSED
A LITTLE FARTHER SOUTH...AND A NORTHERN STREAM IMPULSE SCOOTS
QUICKLY INTO THE MID-ATLANTIC STATES. SEAS 2-4 FT TO BEGIN
WITH...BUT SUBSIDING TO AROUND 2 FT THROUGHOUT IN THE LIGHT
OFFSHORE FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...REK
NEAR TERM...REK
AVIATION...JDW
000
FXUS62 KRAH 201736
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1235 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO CENTRAL NORTH CAROLINA FROM THE
NORTHWEST THROUGH TONIGHT. THE HIGH WILL DRIFT TO OUR NORTHEAST ON
SATURDAY... IN ADVANCE OF THE NEXT STORM SYSTEM WHICH WILL MOVE INTO
THE REGION FROM THE SOUTHWEST AND BRING CLOUDS AND RAIN FOR SUNDAY
AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1235 PM FRIDAY...
FOR THE REST OF TODAY THROUGH TONIGHT: THE LATEST SURFACE ANALYSIS
DEPICTS THE FRONT JUST OFF THE OUTER BANKS WITH THE INCOMING SURFACE
HIGH CENTERED OVER EASTERN KY. A DRY AND SUBSIDING COLUMN SHOULD
KEEP MOST AREAS RELATIVELY FREE FROM CLOUDS THROUGH THIS EVENING.
THE EXCEPTION IS OVER NORTHEAST NC WHERE A SURGE OF MOISTURE JUST
OFF THE SURFACE... NOTED WELL ON THE 12Z 925 MB ANALYSIS AND VISIBLE
SATELLITE IMAGERY... CONTINUES MOVING TOWARD THE SOUTH-SOUTHWEST
JUST AHEAD OF A SECONDARY LOW LEVEL COLD FRONT. THE 12Z/20 12KM NAM
SHOWED THIS FEATURE QUITE WELL... AND FAVORS PARTLY TO MOSTLY CLOUDY
SKIES SPREADING TO THE SOUTH-SOUTHWEST OVER EASTERN NC THROUGH THE
REST OF THIS AFTERNOON. FACTORING IN LOW LEVEL THICKNESSES... THE
CLOUDS IN THE EASTERN CWA... AND MOSTLY SUNNY SKIES ELSEWHERE...
STILL EXPECT HIGHS IN THE MID-UPPER 60S... COOLEST ACROSS THE NORTH
WHERE THE COLD AIR ADVECTION IS MOST PROFOUND. BEHIND THE SURGE OF
LOW LEVEL MOISTURE... SKIES SHOULD BE LARGELY CLOUD-FREE
OVERNIGHT... HOWEVER AS THE SURFACE HIGH SHIFTS UP INTO WV...
SURFACE WINDS IN NC SHOULD BECOME UNIFORM NORTHEASTERLY... AND GIVEN
THE MINOR AMOUNT OF RESIDUAL LOW LEVEL MOISTURE... THE UPSLOPE FLOW
AND RESULTANT LIFT/CONDENSATION COULD LEAD TO POCKETS OF STRATUS IN
THE EXTREME WESTERN CWA LATE TONIGHT. HIGH THIN CLOUDS BLOWING OFF
OF THE GULF COAST CONVECTION... ASSOCIATED WITH OUR NEXT STORM
SYSTEM... WILL START TO SPREAD SOUTHWEST TO NORTHEAST ACROSS THE
STATE LATE TONIGHT AS WELL. UNDER GENERALLY FAIR SKIES... STILL
EXPECT LOWS OF 39-46.
FOR SATURDAY: THE MID LEVEL VORTEX DEEPENING OVER EASTERN TX/OK THIS
AFTERNOON MOVES SLOWLY ACROSS LA/MS THROUGH SATURDAY. MID-UPPER
LEVEL MOISTURE STEADILY INCREASES AND DEEPENS OVER NC... WHILE THE
SURFACE HIGH TO OUR NORTH CONTINUES MOVING NORTHWARD TO A POSITION
OVER LAKE ERIE... WHERE IT BEGINS TO BE SUPPORTED BY CONFLUENT FLOW
ALOFT WITH NORTHERN STREAM SHORTWAVE TROUGHING OVER PA... CAUSING
THE HIGH TO GRADUALLY STRENGTHEN. THIS PATTERN SHOULD ENSURE A
STEADY NORTHEASTERLY FEED OF LOW LEVEL DRY AIR INTO CENTRAL NC...
SETTING US UP FOR DAMMING ONCE THE SURFACE HIGH CAN GET INTO A MORE
FAVORABLE POSITION (OVER THE ST LAWRENCE VALLEY) SATURDAY NIGHT
WHERE IT CAN TAP INTO EVEN COOLER AIR AND STRENGTHEN FURTHER WITH
THE SUPPORT ALOFT PERSISTING. EXPECT STEADILY LOWERING AND
THICKENING CLOUDS THROUGH THE DAY... WITH A FEW LOWER STRATOCUMULUS
OVER THE WESTERN PIEDMONT WITHIN EASTERLY UPSLOPE LOW LEVEL FLOW.
BUT THE MOST ACTION WITH THIS SYSTEM ON SATURDAY WILL BE BANDS OF
CONVECTION OVER AL/GA AND THE NORTHEAST GULF... AND ANY SIGNIFICANT
FORCING TO GENERATE PRECIP OVER NC HOLDS OFF UNTIL AFTER SUNDOWN
SATURDAY WITH NO DISCERNIBLE ISENTROPIC UPGLIDE AND UPPER DIVERGENCE
HOLDING TO OUR SOUTH THROUGH THE DAY... PLUS THE SUBCLOUD LAYER AT
1-3 KM OVER NC REMAINS RATHER DRY. HIGHS 60-65 ARE SUPPORTED BY LOW
LEVEL THICKNESS TRENDS AND ARE NEAR THE LATEST STATISTICAL GUIDANCE.
-GIH
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
AS OF 315 AM FRIDAY...
SATURDAY NIGHT...925-850MB FLOW BACKS AND STRENGTHENS IN RESPONSE TO
APPROACH OF SOUTHERN STREAM LOW PRESSURE SYSTEM LIFTING ACROSS THE
LOWER MS VALLEY. EXPECT CLOUDS TO LOWER THICKEN. ISENTROPIC LIFT
INCREASES TOWARD 12Z IN THE 300-305 LAYER...MORE SO AFTER 12Z. WILL
MAINTAIN DRY CONDITIONS THROUGH 06Z..THEN MAINTAIN CONTINUE PREVIOUS
FORECAST OF INCREASING POPS SW-NE AFTER 06Z. REFRAINED FROM
INCREASING POPS ABOVE 40 PERCENT. RH PROFILES DEPICT RELATIVELY DRY
SUB CLOUD LAYER TILL 12Z SO INITIAL PRECIP WILL GO TOWARD MOISTENING
THIS LAYER. IF MOISTENING OCCURS FASTER THAN EXPECTED THEN COULD SEE
NEED TO INCREASE POPS TO LOW END LIKELY IN THE FAR W-SW. RAISED MIN
TEMPS A FEW DEGREES BASED ON THICKENING CLOUD COVERAGE IN THE WEST.
MIN TEMPS LOWER 40S NE TO MID/UPPER 40S WEST-SOUTH. -WSS
BY 12Z SUNDAY...A SOUTHERN STREAM SHORTWAVE TROUGH IS PROGGED TO
HAVE BECOME NEGATIVELY TILTED...LIFTING FROM THE GULF COAST INTO THE
TN VALLEY REGION. WITH A 1025MB HIGH OVER THE NY/CANADA
BORDER...AND A SURFACE LOW LIFTING NORTHEAST WITH THE
SHORTWAVE...MODELS HAVE BEEN SHOWING A MILLER B TYPE SURFACE
PRESSURE EVOLUTION FOR SUNDAY INTO SUNDAY NIGHT. AS THE SHORTWAVE
AND LOW LIFT NORTHEAST..AND A SOUTHERN STREAM JET IS PULLED
NORTHWARD...UPPER LEVEL DIFFLUENCE WILL INCREASE OVER CENTRAL
NC...AND COMBINED WITH STRENGTHENING 850MB FLOW AND LOW LEVEL WARM
ADVECTION...EXPECT RAIN CHANCES TO INCREASE RAPIDLY SUNDAY MORNING.
THERE ARE STILL SOME INCONSISTENCIES AMONG MODEL GUIDANCE ON THE
STRENGTH OF THE SHORTWAVE AS IT PASSES BY...AND ALSO ON THE TIMING
OF DEVELOPMENT AND MOVEMENT OF THE SECONDARY SURFACE LOW ALONG THE
COAST. THE SHORTWAVE IS EXPECTED TO BE SHEARING OUT AS IT LIFTS
THROUGH THE TN VALLEY REGION...AND THE NAM/GFS ARE STRONGER AND
FASTER THAN THE ECMWF OR CANADIAN...WHOSE LATEST RUNS HAVE COME IN
WITH A MORE MILLER TYPE A SURFACE LOW TRACK (POSSIBLY DUE TO A MORE
SOUTHWARD POSITION OF THE SURFACE HIGH TO OUR NORTH). QPF FORECAST
ALSO SUFFERS FROM THESE DIFFERENCES...BUT THERE SEEMS TO BE A
GENERAL TREND TOWARDS A SPLIT...WITH BEST COVERAGE INITIALLY WITH
THE UPPER WAVE AND ISENTROPIC LIFT IN THE WEST...SHIFTING TO THE
EAST AS THE SECONDARY LOW DEVELOPS OFF THE SAVANNAH COAST SUNDAY
NIGHT AND TRACKS NORTH SOMEWHERE ALONG THE COAST. FOR NOW...WILL
NOT MAKE MANY CHANGES TO THE CURRENT FORECAST...WITH POPS INCREASING
TO LIKELY AFTER 12Z SUNDAY...WITH THE HIGHEST POPS SHIFTING TO THE
EAST AFTER 00Z MONDAY. AS MENTIONED IN EARLIER DISCUSSIONS...THE
CURRENT FORECAST TRACK OF THE COASTAL LOW KEEPS THE CWA ON THE COOL
SIDE OF THE COASTAL FRONT AND THUS VOID OF ANY SURFACE BASED
CONVECTION. HIGHS SUNDAY WILL VARY WIDELY FROM THE COOL CAD AIRMASS
IN THE WEST WHERE MID TO UPPER 40S ARE POSSIBLE...TO WARMER UPPER
50S TO EVEN 60 IN THE SE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 305 AM FRIDAY...
MID LEVEL DRY AIR WILL BRING RAIN TO AN END FROM SW TO NE ON MONDAY
AS A SURFACE HIGH BUILDS ACROSS THE SE US AND WILL HAVE ALL POPS OUT
OF THE CWA BY 00Z TUESDAY. FORECAST LOW LEVEL THICKNESSES CLIMB
20-30M ON MONDAY WITH A WELL MODIFIED HIGH TAKING HOLD. A SLOWER
TRACK OF A COASTAL LOW COULD KEEP CLOUD COVER IN LONGER....A
REINFORCED NORTHERLY FLOW OVER THE AREA... AND HIGHS COOLER. PREFER
A BLEND OF GUIDANCE...59-66 NW-SE.
SURFACE HIGH PRESSURE RIDGE SETTLES OVER THE AREA TUESDAY MORNING
WHICH COULD LEAD TO FOG ISSUES DEPENDING ON ANTECEDENT RAINFALL.
OTHERWISE...TUES LOOKS TO BE A NICE DAY WITH THE NEXT WEATHER SYSTEM
REMAINING WEST OF THE MOUNTAINS. MORNING LOWS COOL IN THE LOW TO
MID 40S. HIGHS IN THE LOW TO MID 60S...JUST ABOVE NORMAL.
MODELS HAVE YET TO SHOW SIGNS OF CONVERGING ON A SOLUTION FOR A
POTENTIAL UPPER LOW OVER THE UPPER MIDWEST BY WEDNESDAY...WITH ITS
COLD FRONT CROSSING THE MOUNTAINS BY WED NIGHT. THE FRONT WOULD BE
WELL SEPARATED FROM ITS PARENT LOW...AND LIKELY VOID OF MUCH
PRECIP. BEHIND THE FRONT...GUIDANCE IS SLOW TO SHOW MUCH AIRMASS
CHANGE...UNTIL A SECOND POTENTIAL CLIPPER SHORTWAVE DIVES SOUTHEAST
THROUGH THE MIDWEST AND INTO THE MID ATLANTIC ON THURS...BRINGING A
SURGE OF COLDER AND DRIER AIR BEHIND IT. CURRENT FORECAST WILL
REMAIN DRY WITH TEMPS FALLING TO BELOW NORMAL BY THEN END OF THE
PERIOD.
&&
.AVIATION /17Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1215 PM FRIDAY...
VFR CONDITIONS WITH UNRESTRICTED CIGS AND VSBYS ARE EXPECTED AT
INT/GSO/RDU/FAY THROUGH TONIGHT... HOWEVER AT RWI... MVFR CONDITIONS
WILL CONTINUE THROUGH MUCH OF THE AFTERNOON. THIS STRATUS IS
ASSOCIATED WITH A SECONDARY FRONT LOCATED A COUPLE THOUSAND FEET OFF
THE SURFACE OVER NORTHEAST NC DROPPING TOWARD THE SOUTH-SOUTHWEST.
SCATTERED MVFR-LEVEL CLOUDS MAY DRIFT NEAR RDU AND FAY THIS
AFTERNOON BUT ARE NOT EXPECTED TO BECOME BROKEN. OTHERWISE... NORTH
TO NORTHEAST WINDS SUSTAINED NEAR 10 KTS MAY PERIODICALLY GUST TO
15-18 KTS THROUGH 21Z. AFTER 21Z... AS THE SURFACE HIGH BUILDS IN
FROM THE NORTHWEST... THE PRESSURE GRADIENT OVER THE AREA WILL RELAX
RESULTING IN SUBSIDING WINDS. SKIES ARE EXPECTED TO BE MOSTLY CLEAR
AFTER SUNDOWN WITH UNRESTRICTED VSBYS AND NO CIGS... ALTHOUGH
SCATTERED CLOUDS AT 2 KFT TO 3 KFT ARE POSSIBLE AT INT/GSO AFTER
MIDNIGHT THROUGH DAYBREAK WITH WEAK UPSLOPE FLOW IN THE LOW LEVELS.
OTHERWISE CLOUD BASES SHOULD HOLD ABOVE 14 KFT THROUGH EARLY
SATURDAY AFTERNOON.
LOOKING BEYOND MIDDAY SATURDAY: A STORM SYSTEM WILL APPROACH FROM
THE SOUTHWEST SATURDAY NIGHT/SUNDAY MORNING AND MAY BRING MVFR OR
IFR CONDITIONS TO THE REGION FOR SUNDAY THROUGH MONDAY. LOW CIGS ARE
EXPECTED TO CLEAR OUT BY MONDAY EVENING BUT AREAS OF IFR/LIFR FOG
MAY DEVELOP LATE MONDAY NIGHT/TUESDAY MORNING. VFR CONDITIONS ARE
ANTICIPATED TUESDAY MORNING THROUGH WEDNESDAY WITH HIGH PRESSURE
BUILDING IN FROM THE SOUTHWEST. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...WSS/SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD
000
FXUS62 KMHX 201656
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
1156 AM EST FRI NOV 20 2009
.SYNOPSIS...
A WEAK COLD FRONT WILL CONTINUE MOVING OFFSHORE THIS AFTERNOON.
HIGH PRES WILL BUILD IN FROM THE N TONIGHT AND SAT...THEN SLIDE
OFFSHORE SAT NIGHT. LOW PRES WILL APPROACH FROM THE SW SUNDAY AND
MOVE NE NEAR OR JUST OFFSHORE OF THE COAST SUN NIGHT INTO MON.
HIGH PRESSURE WILL REBUILD OVER THE AREA TUESDAY THROUGH LATE NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC FRONT HAS MOVED OFF OVER THE GULF STREAM LATE THIS MORN. BKN/OVC
CLOUD SHIELD IN THE POSTFRONTAL MOIST LOW LEVEL NE FLOW DROPPING
SW ACRS THE NE FCST AREA THIS MORN AND WILL CONTINUE SPREADING
OVER THE RMNDR OF THE AREA DURING MIDDAY/EARLY AFTN. HAVE DROPPED
AFTN HIGH TEMPS A FEW DEGS GIVEN THE EXPECTED LIMITED SUNSHINE.
HAVE KEPT SLIGHT TO LOW CHC POPS FOR MAINLY FOR DARE AND HYDE
COUNTIES BUT MOST PRECIP WILL CONTINUE MOVING OFFSHORE THIS AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS OF 230 AM FRIDAY...HIGH PRESSURE WILL BUILD N OF THE REGION
TONIGHT AND SAT WITH DRY WEATHER. SHLD HAVE GOOD RADIATIONAL
COOLING TONIGHT WITH LOWS IN THE LOW TO MID 40S COOLER INLAND
SPOTS. HIGHS SAT WITH PLENTY OF SUN SHLD REACH THE LOW TO MID 60S.
AS HIGH MOVES OFFSHORE TO THE N SAT NIGHT WILL SEE INCREASING
MOISTURE AS LOW LVL FLOW BECOMES MORE ONSHORE. OVERALL ATMS IS DRY
TO START SO NOT LOOKING FOR MUCH RAIN TO DEVELOP SAT
NIGHT...MAINLY LATE NEAR THE COAST. APPROACHING SRT WAVE COMBINED
WITH INCREASING ISENT LIFT SHLD LEAD TO DECENT CVRG OF RAIN SUNDAY
INTO SUNDAY NIGHT. FOR NOW WILL LEAN MORE TWRD NAM/EMCWF KEEPING
MAINLY NE FLOW OVER THE REGION WITH LOW PRES NEAR OR JUST OFF THE
CST LATER SUN INTO MON. THIS WILL ALSO KEEP RAIN THREAT GOING
LONGER THAN PREV FCST INDICATED SO INCREASED POPS TO LIKELY SUN
NIGHT ALL AREAS AND CONT LIKELY INTO MON MORN OVER THE ERN HALF OF
THE AREA. CLOUDS AND PRECIP WILL LIMIT HIGHS TO LOW TO POSS MID
60S SUNDAY AND MON.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...HIGH PRES WILL BUILD IN TUE AND WED WITH DRY
WEATHER. COLD FRONT EXPECTED TO CROSS LATER WED OR EARLY THU AND
MAY SEE SOME RAIN FROM THIS BUT WILL NOT CHANGE CURRENT DRY FCST
UNTIL HAVE MORE CONFIDENCE.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THE FRONT HAS PUSHED E OF RTES AND HIGH PRES BUILDING INTO RTES
FROM THE W AND N WITH NLY FLOW INCREASING ACROSS THE REGION. THIS
IS ALSO INCREASING MOISTURE BELOW A LOW LEVEL INVERSION RESULTING
IN MVFR TO IFR CIGS ACROSS RTES. EXPECT REDUCED CIGS TO IMPACT
RTES THROUGH TODAY. GUIDANCE SUGGESTING CLEARING INLAND THIS
EVENING BUT ONLY SLOW CLEARING ACROSS ERN RTES THROUGH THE
OVERNIGHT.
VFR SAT-SUN WITH HIGH PRES EXTENDING IN...THEN CONDITIONS
LOWERING SUN NIGHT-MON WITH LOW PRES MOVING ACROSS. CONDITIONS
IMPROVING AGAIN MON NIGHT-TUE WITH HIGH PRES AGAIN.
&&
.MARINE...
THE FRONT HAS PUSHED E OF THE REGION AND A NLY SURGE IS PUSHING S
ACROSS THE WATERS LATE THIS MORNING. WINDS AROUND 20 TO 25 KT CAN
BE EXPECTED MUCH OF THE AFTERNOON WITH WINDS GRADUALLY DIMINISHING
TONIGHT. SEAS REMAIN AROUND 5 TO 6 FT ACROSS MOST WATERS...A BIT
LOWER NEARSHORE SRN WATERS WITH OFFSHORE FLOW...BUT WILL LIKELY
BUILD A FOOT OR TWO NRN AND OUTER SRN WATERS THIS AFTERNOON WITH
INCREASED WINDS. HAVE RAISED AND SC EXCERCISE CAUTION FOR THE
SOUNDS WITH WINDS AROUND 20 KT WITH HIGHER GUSTS EXPECTED AND SCA
CONTINUES FOR REMAINING WATERS.
MODERATE NE WINDS AND HIGHER SEAS WILL PERSIST TONIGHT INTO SAT. LOW
CONFIDENCE FCST WITH NEXT LOW PRES SYSTEM AFFECTING AREA LATE SUN
INTO MON AND DID NOT MAKE SIGNIFICANT CHANGE TO PREVIOUS
FCST...KEEPING LOW TRACK OFFSHORE. MODELS ARE TRENDING MORE TOWARD
MOVEMENT ALONG COAST BUT WILL LET DAY SHIFT TAKE A LOOK.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 4 PM EST
SATURDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY UNTIL 10 AM EST SATURDAY FOR AMZ150.
&&
$$
SYNOPSIS...RF
NEAR TERM...BTC/RF
SHORT TERM...RF
LONG TERM...RF
AVIATION...JBM
MARINE...JBM
000
FXUS62 KMHX 201606
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
1106 AM EST FRI NOV 20 2009
.SYNOPSIS...
A WEAK COLD FRONT WILL CONTINUE MOVING OFFSHORE THIS AFTERNOON.
HIGH PRES WILL BUILD IN FROM THE N TONIGHT AND SAT...THEN SLIDE
OFFSHORE SAT NIGHT. LOW PRES WILL APPROACH FROM THE SW SUNDAY AND
MOVE NE NEAR OR JUST OFFSHORE OF THE COAST SUN NIGHT INTO MON.
HIGH PRESSURE WILL REBUILD OVER THE AREA TUESDAY THROUGH LATE NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC FRONT HAS MOVED OFF OVER THE GULF STREAM LATE THIS MORN. BKN/OVC
CLOUD SHIELD IN THE POSTFRONTAL MOIST LOW LEVEL NE FLOW DROPPING
SW ACRS THE NE FCST AREA THIS MORN AND WILL CONTINUE SPREADING
OVER THE RMNDR OF THE AREA DURING MIDDAY/EARLY AFTN. HAVE DROPPED
AFTN HIGH TEMPS A FEW DEGS GIVEN THE EXPECTED LIMITED SUNSHINE.
HAVE KEPT SLIGHT TO LOW CHC POPS FOR MAINLY FOR DARE AND HYDE
COUNTIES BUT MOST PRECIP WILL CONTINUE MOVING OFFSHORE THIS AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
AS OF 230 AM FRIDAY...HIGH PRESSURE WILL BUILD N OF THE REGION
TONIGHT AND SAT WITH DRY WEATHER. SHLD HAVE GOOD RADIATIONAL
COOLING TONIGHT WITH LOWS IN THE LOW TO MID 40S COOLER INLAND
SPOTS. HIGHS SAT WITH PLENTY OF SUN SHLD REACH THE LOW TO MID 60S.
AS HIGH MOVES OFFSHORE TO THE N SAT NIGHT WILL SEE INCREASING
MOISTURE AS LOW LVL FLOW BECOMES MORE ONSHORE. OVERALL ATMS IS DRY
TO START SO NOT LOOKING FOR MUCH RAIN TO DEVELOP SAT
NIGHT...MAINLY LATE NEAR THE COAST. APPROACHING SRT WAVE COMBINED
WITH INCREASING ISENT LIFT SHLD LEAD TO DECENT CVRG OF RAIN SUNDAY
INTO SUNDAY NIGHT. FOR NOW WILL LEAN MORE TWRD NAM/EMCWF KEEPING
MAINLY NE FLOW OVER THE REGION WITH LOW PRES NEAR OR JUST OFF THE
CST LATER SUN INTO MON. THIS WILL ALSO KEEP RAIN THREAT GOING
LONGER THAN PREV FCST INDICATED SO INCREASED POPS TO LIKELY SUN
NIGHT ALL AREAS AND CONT LIKELY INTO MON MORN OVER THE ERN HALF OF
THE AREA. CLOUDS AND PRECIP WILL LIMIT HIGHS TO LOW TO POSS MID
60S SUNDAY AND MON.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...HIGH PRES WILL BUILD IN TUE AND WED WITH DRY
WEATHER. COLD FRONT EXPECTED TO CROSS LATER WED OR EARLY THU AND
MAY SEE SOME RAIN FROM THIS BUT WILL NOT CHANGE CURRENT DRY FCST
UNTIL HAVE MORE CONFIDENCE.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
LIGHT WINDS AND MOIST LOW LVLS LEADING TO WDSPRD IFR CIGS EARLY THIS
MORNING WITH MAINLY MVFR VSBYS. FRONT WILL PUSH OFFSHORE EARLY THIS
MORNING BUT NO STRONG DRYING BEHIND IT AND MODEL RH XSCTNS INDICATE
CIGS LIFTING BUT NOT SCATTERING OUT UNTIL AFTN. ENOUGH DRYING
TONIGHT FOR VFR.
VFR CONTINUING SAT-SUN WITH HIGH PRES EXTENDING IN...THEN CONDITIONS
LOWERING SUN NIGHT-MON WITH LOW PRES MOVING ACROSS. CONDITIONS
IMPROVING AGAIN MON NIGHT-TUE WITH HIGH PRES AGAIN.
&&
.MARINE...
FRONT MOVING ACROSS WATERS EARLY THIS MORNING AND CAA SURGE TO
AROUND SCA SPEEDS EXPECTED BEHIND IT DURING THE DAY. NW-N WINDS WILL
INCREASE FIRST OVER SRN WATERS EARLY THIS MORNING BUT MAIN SURGE
WILL DEVELOPE MID-MORNING OVER NRN WATERS AND SPREAD S THROUGH EARLY
AFTN. KEPT SPEEDS AT 15-20 KTS ALL WATERS BUT MENTIONED GUSTS TO 25
KT OUTER WATERS. SEAS MAY DROP BELOW 6 FT BRIEFLY THIS MORNING FOR
NRN AND CENTRAL WATERS BUT WILL INCREASE QUICKLY WITH SURGE...THUS
KEPT SCA IN PLACE. DID DROP SCA EARLY FOR SRN WATERS BUT STARTED IT
AGAIN LATE AFTN.
MODERATE NE WINDS AND HIGHER SEAS WILL PERSIST TONIGHT INTO SAT. LOW
CONFIDENCE FCST WITH NEXT LOW PRES SYSTEM AFFECTING AREA LATE SUN
INTO MON AND DID NOT MAKE SIGNIFICANT CHANGE TO PREVIOUS
FCST...KEEPING LOW TRACK OFFSHORE. MODELS ARE TRENDING MORE TOWARD
MOVEMENT ALONG COAST BUT WILL LET DAY SHIFT TAKE A LOOK.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 4 PM EST
SATURDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY UNTIL 10 AM EST SATURDAY FOR AMZ150.
&&
$$
SYNOPSIS...RF
NEAR TERM...BTC/RF
SHORT TERM...RF
LONG TERM...RF
AVIATION...JBM
MARINE...JBM
000
FXUS62 KRAH 201456
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1050 AM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO CENTRAL NORTH CAROLINA TODAY AND
SETTLE OVERHEAD TONIGHT. THE HIGH WILL DRIFT TO OUR NORTHEAST ON
SATURDAY... IN ADVANCE OF THE NEXT STORM SYSTEM EXPECTED TO APPROACH
FROM THE SOUTHWEST AND AFFECT THE REGION SUNDAY AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 AM FRIDAY...
THE LATEST SURFACE ANALYSIS DEPICTS THE FRONT JUST ALONG THE OUTER
BANKS WITH THE INCOMING SURFACE HIGH CENTERED OVER EASTERN KY. ALL
FOG ACROSS THE AREA HAS MIXED OUT WITH THE INFLUX OF LOW LEVEL DRY
AIR. THE EXCEPTION TO THE DRYING IS OVER NORTHEAST NC WHERE A SURGE
OF MOISTURE JUST OFF THE SURFACE... NOTED WELL ON THE 12Z 925 MB
ANALYSIS AND VISIBLE SATELLITE IMAGERY... IS MOVING TOWARD THE
SOUTH-SOUTHWEST JUST AHEAD OF A SECONDARY LOW LEVEL COLD FRONT. THE
12Z/20 12KM NAM SHOWS THIS FEATURE QUITE WELL... AND FAVORS A PERIOD
OF PARTLY TO MOSTLY CLOUDY SKIES SPREADING TO THE SOUTH-SOUTHWEST
OVER EASTERN NC THROUGH THIS AFTERNOON. APPROPRIATE ADJUSTMENTS HAVE
BEEN MADE TO THE FORECAST TO SHOW THIS PATTERN. LOW LEVEL
THICKNESSES SUPPORT HIGHS NEAR THE CURRENT FORECAST OF MID-UPPER 60S
WITH PLENTY OF SUNSHINE... BUT HAVE TRIMMED TEMPS BACK A COUPLE OF
DEGREES MAINLY IN THE EASTERN CWA TO ACCOUNT FOR THE SURGE OF
STRATUS. -GIH
TONIGHT...MODEL RH PROFILE CONTINUE TO DEPICT RETURN OF HIGH LEVEL
MOISTURE IN ADVANCE OF SOUTHERN STREAM S/W. STILL SOME UNCERTAINTY
AS TO OPAQUENESS OF HIGH CLOUDS THOUGH AND MOS GUIDANCE KEEP SKY
COVERAGE NO WORSE THAN FEW. THUS SHOULD SEE DECENT NOCTURNAL COOLING
CONDITIONS TONIGHT. IF TOP SOIL WAS NOT SO SATURATED...COULD SEE
TEMPS LOWER INTO THE LOW AND MID 30S. HOWEVER RESIDUAL LOW LEVEL
MOISTURE WILL MAINTAIN SOME WARMTH NEAR THE SURFACE SO EXPECT MIN
TEMPS UPPER 30S NEAR 40 NW TO MID 40S SE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 315 AM FRIDAY...
MID/UPPER LEVEL MOISTURE INCREASES AND DEEPENS SATURDAY IN SW FLOW
OVERHEAD IN ADVANCE OF SOUTHERN STREAM SYSTEM IN THE NW GULF.
MEANWHILE PARENT SURFACE HIGH MIGRATES FROM THE LOWER OH VALLEY
TOWARD THE EASTERN LAKES WITH RIDGE EXTENDING INTO THE WESTERN
PIEDMONT. THIS WILL RESULT IN A N-NE LOW LEVEL FLOW...ADVECTING
COOL AND RELATIVELY DRY AIR. MAX TEMPS SATURDAY DEPENDENT UPON WHEN
MID/HIGH CLOUDS BECOME OPAQUE ENOUGH TO BLOCK OUT SUN. WILL MAINTAIN
MAX TEMPS AS PER PREVIOUS FORECAST (AROUND 60 NW TO MID 60S SE). IF
GFS CORRECT...SKIES BECOME OVERCAST BY MIDDAY. IF THIS OCCURS...MAX
TEMPS WILL LIKELY BE 3-4 DEGREES COOLER...ESPECIALLY IN THE
WEST.
SATURDAY NIGHT...925-850MB FLOW BACKS AND STRENGTHENS IN RESPONSE TO
APPROACH OF SOUTHERN STREAM LOW PRESSURE SYSTEM LIFTING ACROSS THE
LOWER MS VALLEY. EXPECT CLOUDS TO LOWER THICKEN. ISENTROPIC LIFT
INCREASES TOWARD 12Z IN THE 300-305 LAYER...MORE SO AFTER 12Z. WILL
MAINTAIN DRY CONDITIONS THROUGH 06Z..THEN MAINTAIN CONTINUE PREVIOUS
FORECAST OF INCREASING POPS SW-NE AFTER 06Z. REFRAINED FROM
INCREASING POPS ABOVE 40 PERCENT. RH PROFILES DEPICT RELATIVELY DRY
SUB CLOUD LAYER TILL 12Z SO INITIAL PRECIP WILL GO TOWARD MOISTENING
THIS LAYER. IF MOISTENING OCCURS FASTER THAN EXPECTED THEN COULD SEE
NEED TO INCREASE POPS TO LOW END LIKELY IN THE FAR W-SW. RAISED MIN
TEMPS A FEW DEGREES BASED ON THICKENING CLOUD COVERAGE IN THE WEST.
MIN TEMPS LOWER 40S NE TO MID/UPPER 40S WEST-SOUTH. -WSS
BY 12Z SUNDAY...A SOUTHERN STREAM SHORTWAVE TROUGH IS PROGGED TO
HAVE BECOME NEGATIVELY TILTED...LIFTING FROM THE GULF COAST INTO THE
TN VALLEY REGION. WITH A 1025MB HIGH OVER THE NY/CANADA
BORDER...AND A SURFACE LOW LIFTING NORTHEAST WITH THE
SHORTWAVE...MODELS HAVE BEEN SHOWING A MILLER B TYPE SURFACE
PRESSURE EVOLUTION FOR SUNDAY INTO SUNDAY NIGHT. AS THE SHORTWAVE
AND LOW LIFT NORTHEAST..AND A SOUTHERN STREAM JET IS PULLED
NORTHWARD...UPPER LEVEL DIFFLUENCE WILL INCREASE OVER CENTRAL
NC...AND COMBINED WITH STRENGTHENING 850MB FLOW AND LOW LEVEL WARM
ADVECTION...EXPECT RAIN CHANCES TO INCREASE RAPIDLY SUNDAY MORNING.
THERE ARE STILL SOME INCONSISTENCIES AMONG MODEL GUIDANCE ON THE
STRENGTH OF THE SHORTWAVE AS IT PASSES BY...AND ALSO ON THE TIMING
OF DEVELOPMENT AND MOVEMENT OF THE SECONDARY SURFACE LOW ALONG THE
COAST. THE SHORTWAVE IS EXPECTED TO BE SHEARING OUT AS IT LIFTS
THROUGH THE TN VALLEY REGION...AND THE NAM/GFS ARE STRONGER AND
FASTER THAN THE ECMWF OR CANADIAN...WHOSE LATEST RUNS HAVE COME IN
WITH A MORE MILLER TYPE A SURFACE LOW TRACK (POSSIBLY DUE TO A MORE
SOUTHWARD POSITION OF THE SURFACE HIGH TO OUR NORTH). QPF FORECAST
ALSO SUFFERS FROM THESE DIFFERENCES...BUT THERE SEEMS TO BE A
GENERAL TREND TOWARDS A SPLIT...WITH BEST COVERAGE INITIALLY WITH
THE UPPER WAVE AND ISENTROPIC LIFT IN THE WEST...SHIFTING TO THE
EAST AS THE SECONDARY LOW DEVELOPS OFF THE SAVANNAH COAST SUNDAY
NIGHT AND TRACKS NORTH SOMEWHERE ALONG THE COAST. FOR NOW...WILL
NOT MAKE MANY CHANGES TO THE CURRENT FORECAST...WITH POPS INCREASING
TO LIKELY AFTER 12Z SUNDAY...WITH THE HIGHEST POPS SHIFTING TO THE
EAST AFTER 00Z MONDAY. AS MENTIONED IN EARLIER DISCUSSIONS...THE
CURRENT FORECAST TRACK OF THE COASTAL LOW KEEPS THE CWA ON THE COOL
SIDE OF THE COASTAL FRONT AND THUS VOID OF ANY SURFACE BASED
CONVECTION. HIGHS SUNDAY WILL VARY WIDELY FROM THE COOL CAD AIRMASS
IN THE WEST WHERE MID TO UPPER 40S ARE POSSIBLE...TO WARMER UPPER
50S TO EVEN 60 IN THE SE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 305 AM FRIDAY...
MID LEVEL DRY AIR WILL BRING RAIN TO AN END FROM SW TO NE ON MONDAY
AS A SURFACE HIGH BUILDS ACROSS THE SE US AND WILL HAVE ALL POPS OUT
OF THE CWA BY 00Z TUESDAY. FORECAST LOW LEVEL THICKNESSES CLIMB
20-30M ON MONDAY WITH A WELL MODIFIED HIGH TAKING HOLD. A SLOWER
TRACK OF A COASTAL LOW COULD KEEP CLOUD COVER IN LONGER....A
REINFORCED NORTHERLY FLOW OVER THE AREA... AND HIGHS COOLER. PREFER
A BLEND OF GUIDANCE...59-66 NW-SE.
SURFACE HIGH PRESSURE RIDGE SETTLES OVER THE AREA TUESDAY MORNING
WHICH COULD LEAD TO FOG ISSUES DEPENDING ON ANTECEDENT RAINFALL.
OTHERWISE...TUES LOOKS TO BE A NICE DAY WITH THE NEXT WEATHER SYSTEM
REMAINING WEST OF THE MOUNTAINS. MORNING LOWS COOL IN THE LOW TO
MID 40S. HIGHS IN THE LOW TO MID 60S...JUST ABOVE NORMAL.
MODELS HAVE YET TO SHOW SIGNS OF CONVERGING ON A SOLUTION FOR A
POTENTIAL UPPER LOW OVER THE UPPER MIDWEST BY WEDNESDAY...WITH ITS
COLD FRONT CROSSING THE MOUNTAINS BY WED NIGHT. THE FRONT WOULD BE
WELL SEPARATED FROM ITS PARENT LOW...AND LIKELY VOID OF MUCH
PRECIP. BEHIND THE FRONT...GUIDANCE IS SLOW TO SHOW MUCH AIRMASS
CHANGE...UNTIL A SECOND POTENTIAL CLIPPER SHORTWAVE DIVES SOUTHEAST
THROUGH THE MIDWEST AND INTO THE MID ATLANTIC ON THURS...BRINGING A
SURGE OF COLDER AND DRIER AIR BEHIND IT. CURRENT FORECAST WILL
REMAIN DRY WITH TEMPS FALLING TO BELOW NORMAL BY THEN END OF THE
PERIOD.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AS OF 1050 AM FRIDAY...
VFR CONDITIONS WITH UNRESTRICTED CIGS AND VSBYS ARE EXPECTED AT
INT/GSO/RDU/FAY THROUGH TONIGHT... HOWEVER AT RWI... IFR TO MVFR
CONDITIONS WILL RETURN FOR LATE MORNING THROUGH MUCH OF THE
AFTERNOON. THIS STRATUS IS ASSOCIATED WITH A SECONDARY FRONT LOCATED
A COUPLE THOUSAND FEET OFF THE SURFACE DROPPING TOWARD THE
SOUTH-SOUTHWEST OVER NORTHEAST NC. SCATTERED MVFR LEVEL CLOUDS MAY
DRIFT NEAR RDU AND FAY THIS AFTERNOON BUT ARE NOT EXPECTED TO BECOME
BROKEN. OTHERWISE... NORTH TO NORTHEAST WINDS SUSTAINED NEAR 10 KTS
MAY PERIODICALLY GUST TO 15-18 THROUGH 20Z. AFTER 20Z... THE
INFLUENCE OF SURFACE HIGH BUILDING IN FROM THE NORTHWEST WILL CAUSE
WINDS TO GRADUALLY SUBSIDE. SKIES ARE EXPECTED TO BE MOSTLY CLEAR
AFTER SUNDOWN WITH UNRESTRICTED VSBYS AND NO CIGS.
LOOKING BEYOND TONIGHT: A STORM SYSTEM WILL APPROACH FROM THE
SOUTHWEST SATURDAY NIGHT/SUNDAY MORNING AND MAY BRING MVFR OR IFR
CONDITIONS TO THE REGION FOR SUNDAY THROUGH MONDAY. LOW CIGS ARE
EXPECTED TO CLEAR OUT BY MONDAY EVENING BUT AREAS OF IFR/LIFR FOG
MAY DEVELOP LATE MONDAY NIGHT/TUESDAY MORNING. VFR CONDITIONS ARE
ANTICIPATED TUESDAY MORNING THROUGH WEDNESDAY WITH HIGH PRESSURE
BUILDING IN FROM THE SOUTHWEST. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/WSS
SHORT TERM...WSS/SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD
000
FXUS62 KILM 201442
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
942 AM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHWEST TODAY
AND SATURDAY. LOW PRESSURE EMERGING FROM THE GULF OF MEXICO WILL
BRING RAIN TO THE EASTERN CAROLINAS SUNDAY THROUGH EARLY
MONDAY...PULLING AWAY TO THE NORTHEAST BY MONDAY AFTERNOON. MILD
WEATHER CONDITIONS CAN BE EXPECTED MUCH OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM FRIDAY...NORTHERLY FLOW PICKING UP AS HIGH PRESSURE
PUSHES IN FROM THE WEST AND A COLD FRONT MOVES FURTHER OFFSHORE.
MODEL AND ACTUAL AREA SOUNDINGS AND WATER VAPOR PICS SHOW VERY DRY
AIR MOVING IN ALOFT. ANALYSIS OF MORNING DATA SHOWS TODAY WILL BE
A DRY AND STABLE ONE WITH PARTLY CLOUDY SKIES. PRESENT EXTENSIVE
AREA OF STRATUS IS BURNING OFF AS DAYTIME MIXING
COMMENCES...BRINGING DOWN THE DRYER AIR FROM ALOFT. ENOUGH LOW
LEVEL MOISTURE WILL REMAIN FOR SOME FLAT CU TO DEVELOP THIS
AFTERNOON UNDER A SUBSIDENCE INVERSION. SATELLITE AND MODEL CROSS
SECTIONS SUGGEST CIRRUS MOVING IN THE EVENING AND OVERNIGHT FROM
THE GULF COAST STATES. MAX TEMP TODAY RIGHT AROUND 70.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...WILL CONTINUE THE TREND OF SLOWING DOWN A
COMPLEX STORM SYSTEM THAT WILL LIFT OUT OF THE GULF THIS WEEKEND.
IT NOW APPEARS THAT THE CWA WILL REMAIN DRY FOR ALL OF SATURDAY
AND INTO SATURDAY EVENING. MAX TEMPS NEAR NORMAL FOR THIS TIME OF
YEAR...LIMITED MAINLY BY INCREASING HIGH CLOUDS AHEAD OF THE LOW
DEVELOPING ALONG THE GULF COAST.
LATEST NAM AND GFS ARE NOW DEPICTING MILLER TYPE-B CYCLOGENESIS AS
WE HEAD INTO SUNDAY...BUT AT THIS POINT THINK THE MAIN POINT IS
THAT IT WILL HAPPEN MORE SLOWLY. ENOUGH DRY AIR FROM 850-750MB
THAT IT WILL TAKE MOST OF SATURDAY NIGHT TO OVERCOME...SO HAVE
TAPERED POPS FROM HIGH CHANCE IN THE SOUTH TO LOW CHANCE IN THE
NORTH. WENT WITH LIKELY SUNDAY INTO SUNDAY NIGHT AS THE MOISTURE
FEED BECOMES WELL ESTABLISHED AROUND 12Z SUN...AND PERSISTS BEYOND
00Z MON. THERE IS CERTAINLY AN ARGUMENT TO BE MADE FOR A RAPID
SHUTOFF IN THE PRECIP SUN NIGHT...BUT NOT GETTING TOO CUTE WITH
THE TIMING THIS FAR OUT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...DRY WEATHER PATTERN IN STORE FOR THE
EXTENDED...WITH CHILLY AIR KNOCKING ON THE DOOR BY THE END. SFC
RIDGING ALONG THE GULF COAST AND A FLAT UPPER PATTERN WILL KEEP
TEMPS MILD...WITH HIGHS CLOSE TO 70 MON-WED AND LOWS ALSO A
CATEGORY OR TWO ABOVE CLIMO. BY THURSDAY LOOK FOR A FULL-LATITUDE
TROUGH TO SETTLE IN ALONG THE EAST COAST. HARD TO TIME THE
ASSOCIATED COLD FRONT...BUT REGARDLESS IT LOOKS TO BE MOISTURE-
STARVED...SO NO POPS WILL BE INCLUDED AT THIS TIME. DAYTIME TEMPS
NEAR NORMAL FOR TURKEY DAY...AS THE CHILLY AIR HOLDS OFF UNTIL
BEYOND THE VALID PERIOD OF THE ZONE FORECAST.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
COLD FRONT LOCATED JUST OFFSHORE WILL SLOWLY PULL FURTHER EAST
TODAY BRINGING MODERATE N/NE WINDS AND CLEARING SKY CONDITIONS TO
THE TERMINALS.
LIFR FOG AGAIN OCCURRING AT FLO THIS MORNING...WITH IFR AT LBT...AND
MVFR AT ILM. ALL OF THIS FOG WILL BURN OFF BY 14Z...AND INCREASING
NORTH WINDS WILL HELP SCOUR OUT ANY REMAINING IFR STRATUS. THE
LOWEST LEVELS OF THE ATMOSPHERIC COLUMN ARE STILL QUITE MOIST...SO
EXPECT SOME SCT LOW LEVEL STRATUS TO HANG AROUND THROUGH THE
MORNING. VFR VSBYS AND CIGS WILL BE THE RULE AT ALL TERMINALS AFTER
14Z TODAY EVEN WITH THE LOW STRATUS. THIS AFTN SOME STRATOCU MAY
DEVELOP AROUND 2500 FEET. SOME OF THE GUIDANCE IS SUGGESTING THAT A
BKN CIG MAY DEVELOP THIS AFTN...BUT WITH SUBSIDENCE BEHIND THE FRONT
HAVE ONLY PUT SCT IN THE TAFS. ANY CU WILL BE VERY SHALLOW THOUGH AS
MID LEVELS ARE VERY DRY. WINDS WILL BE AROUND 8 TO 12 KT FROM THE
N/NE AS MIXING WILL ALLOW SOME HIGHER SPEEDS TODAY. TONIGHT...MOSTLY
CLEAR SKY CONDITIONS WITH ONLY SOME HIGH CIRRUS OR LEFTOVER STRATOCU
AT THE TERMINALS. IF WINDS CAN DECOUPLE TONIGHT THERE MAY BE SOME
LIGHT FOG AT LBT/FLO...BUT NOTHING LIKE WHAT HAS OCCURRED THE
PREVIOUS 2 DAYS.
EXTENDED OUTLOOK...VFR SATURDAY. SHOWERS AND LOW CEILINGS SUNDAY
THROUGH MONDAY. FOG POSSIBLE TUESDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM FRIDAY...NORTHERLY WINDS PICKING UP AS HIGH PRESSURE
PUSHES IN FROM THE WEST AND A COLD FRONT MOVES FURTHER EAST OF THE
WATERS. WINDS WILL VEER TO THE NE THIS EVENING AS HIGH PRESSURE
BUILDS FURTHER EAST. WINDS WILL BE RIGHT AROUND 15 KTS THRU THE
NEAR TERM...WITH SEAS STAYING IN THE 2 TO 4 FT RANGE.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...EXPECT STATUS QUO WITH NE WINDS SATURDAY AND
SATURDAY NIGHT. FOR NOW WILL KEEP SPEEDS AROUND 15 KT...BUT THE
GRADIENT APPEARS TO TIGHTEN BY SUNDAY MORNING. COULD SEE A SOLID
20 KT...AND THE NE FETCH WILL BE PERSISTENT ENOUGH TO GENERATE
SOME 6 FT SEAS ALONG FRYING PAN SHOALS AND OFF CAPE ROMAIN. NOT
NEARLY AS MUCH FETCH TO WORK WITH NEAR SHORE...SO LOOK FOR A MUCH
MORE MODEST 2-3 FT THERE.
SUNDAY NIGHT IS THE LOW CONFIDENCE PORTION OF THE FORECAST. LATEST
NAM AND GFS NOW TRY TO PULL THE LOW IN OVER LAND AS IT CROSSES
EASTERN NC. NOT SOLD ENOUGH ON THIS SOLUTION JUST YET...SO WILL
REMAIN CLOSE TO THE PREVIOUS FORECAST WHICH MAINTAINS AN OFFSHORE
TRACK. WILL BRING THE LOW CLOSE ENOUGH TO SEE A VEERING TO ENE
AHEAD OF IT...AND BACKING TO NW AS THE LOW DEPARTS. LOOK FOR A
DIMINISHING TREND IN WINDS DUE TO PROXIMITY OF THE LOW...AND SEAS
GENERALLY IN THE 3-4 FT RANGE FOR MUCH OF THE NIGHT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...WILL START OFF MONDAY WITH NW WINDS BEHIND
DEPARTING LOW PRESSURE. WITH THE HIGH BUILDING FROM THE GULF COAST
AND FLAT RIDGING ALOFT...WOULD NOT EXPECT ANY COLD AIR SURGE...SO
WIND SPEEDS WILL REMAIN QUITE TAME...AROUND 10 KT. COULD SEE WINDS
BACK AROUND TO WESTERLY ON TUESDAY AS THE SFC RIDGE IS SUPPRESSED
A LITTLE FARTHER SOUTH...AND A NORTHERN STREAM IMPULSE SCOOTS
QUICKLY INTO THE MID-ATLANTIC STATES. SEAS 2-4 FT TO BEGIN
WITH...BUT SUBSIDING TO AROUND 2 FT THROUGHOUT IN THE LIGHT
OFFSHORE FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...REK
NEAR TERM...REK
000
FXUS62 KRAH 201151
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
650 AM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO CENTRAL NORTH CAROLINA TODAY AND
SETTLE OVERHEAD TONIGHT. THE HIGH WILL DRIFT EAST SATURDAY...IN
ADVANCE OF THE NEXT STORM SYSTEM EXPECTED TO EFFECT THE REGION
SUNDAY AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 605 AM FRIDAY...
CANCELED DENSE FOG ADVISORY. WHILE WIDESPREAD FOG
OCCURRING...VISIBILITIES MAINLY AT OR ABOVE MILE WITH JUST POCKETS
WHERE THE VISIBILITY IS A HALF MILE OR LESS. VISIBILITIES WILL
IMPROVE RAPIDLY WITHIN AN HOUR OR TWO AFTER SUNRISE.
OTHERWISE HIGH PRESSURE WILL BUILD INTO THE FORECAST AREA TODAY.
EXPECT STEADY NLY BREEZE AFTER SUNRISE WITH INFREQUENT GUSTS THIS
MORNING BETWEEN 15-20KTS. ASIDE FROM A FEW-SCATTERED CLOUDS AROUND
2000FT...EXPECT A LOT OF SUN TODAY. THICKNESSES WITH FULL SUN
SUPPORT TEMPS IN THE LOW/MID 60S WITH UPPER 60S POSSIBLE SE. MOS
GUIDANCE SIMILAR AS WELL AS PREVIOUS FORECAST SO SEE LITTLE NEED TO
ADJUST.
TONIGHT...MODEL RH PROFILE CONTINUE TO DEPICT RETURN OF HIGH LEVEL
MOISTURE IN ADVANCE OF SOUTHERN STREAM S/W. STILL SOME UNCERTAINTY
AS TO OPAQUENESS OF HIGH CLOUDS THOUGH AND MOS GUIDANCE KEEP SKY
COVERAGE NO WORSE THAN FEW. THUS SHOULD SEE DECENT NOCTURNAL COOLING
CONDITIONS TONIGHT. IF TOP SOIL WAS NOT SO SATURATED...COULD SEE
TEMPS LOWER INTO THE LOW AND MID 30S. HOWEVER RESIDUAL LOW LEVEL
MOISTURE WILL MAINTAIN SOME WARMTH NEAR THE SURFACE SO EXPECT MIN
TEMPS UPPER 30S NEAR 40 NW TO MID 40S SE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 315 AM FRIDAY...
MID/UPPER LEVEL MOISTURE INCREASES AND DEEPENS SATURDAY IN SW FLOW
OVERHEAD IN ADVANCE OF SOUTHERN STREAM SYSTEM IN THE NW GULF.
MEANWHILE PARENT SURFACE HIGH MIGRATES FROM THE LOWER OH VALLEY
TOWARD THE EASTERN LAKES WITH RIDGE EXTENDING INTO THE WESTERN
PIEDMONT. THIS WILL RESULT IN A N-NE LOW LEVEL FLOW...ADVECTING
COOL AND RELATIVELY DRY AIR. MAX TEMPS SATURDAY DEPENDENT UPON WHEN
MID/HIGH CLOUDS BECOME OPAQUE ENOUGH TO BLOCK OUT SUN. WILL MAINTAIN
MAX TEMPS AS PER PREVIOUS FORECAST (AROUND 60 NW TO MID 60S SE). IF
GFS CORRECT...SKIES BECOME OVERCAST BY MIDDAY. IF THIS OCCURS...MAX
TEMPS WILL LIKELY BE 3-4 DEGREES COOLER...ESPECIALLY IN THE
WEST.
SATURDAY NIGHT...925-850MB FLOW BACKS AND STRENGTHENS IN RESPONSE TO
APPROACH OF SOUTHERN STREAM LOW PRESSURE SYSTEM LIFTING ACROSS THE
LOWER MS VALLEY. EXPECT CLOUDS TO LOWER THICKEN. ISENTROPIC LIFT
INCREASES TOWARD 12Z IN THE 300-305 LAYER...MORE SO AFTER 12Z. WILL
MAINTAIN DRY CONDITIONS THROUGH 06Z..THEN MAINTAIN CONTINUE PREVIOUS
FORECAST OF INCREASING POPS SW-NE AFTER 06Z. REFRAINED FROM
INCREASING POPS ABOVE 40 PERCENT. RH PROFILES DEPICT RELATIVELY DRY
SUB CLOUD LAYER TILL 12Z SO INITIAL PRECIP WILL GO TOWARD MOISTENING
THIS LAYER. IF MOISTENING OCCURS FASTER THAN EXPECTED THEN COULD SEE
NEED TO INCREASE POPS TO LOW END LIKELY IN THE FAR W-SW. RAISED MIN
TEMPS A FEW DEGREES BASED ON THICKENING CLOUD COVERAGE IN THE WEST.
MIN TEMPS LOWER 40S NE TO MID/UPPER 40S WEST-SOUTH. -WSS
BY 12Z SUNDAY...A SOUTHERN STREAM SHORTWAVE TROUGH IS PROGGED TO
HAVE BECOME NEGATIVELY TILTED...LIFTING FROM THE GULF COAST INTO THE
TN VALLEY REGION. WITH A 1025MB HIGH OVER THE NY/CANADA
BORDER...AND A SURFACE LOW LIFTING NORTHEAST WITH THE
SHORTWAVE...MODELS HAVE BEEN SHOWING A MILLER B TYPE SURFACE
PRESSURE EVOLUTION FOR SUNDAY INTO SUNDAY NIGHT. AS THE SHORTWAVE
AND LOW LIFT NORTHEAST..AND A SOUTHERN STREAM JET IS PULLED
NORTHWARD...UPPER LEVEL DIFFLUENCE WILL INCREASE OVER CENTRAL
NC...AND COMBINED WITH STRENGTHENING 850MB FLOW AND LOW LEVEL WARM
ADVECTION...EXPECT RAIN CHANCES TO INCREASE RAPIDLY SUNDAY MORNING.
THERE ARE STILL SOME INCONSISTENCIES AMONG MODEL GUIDANCE ON THE
STRENGTH OF THE SHORTWAVE AS IT PASSES BY...AND ALSO ON THE TIMING
OF DEVELOPMENT AND MOVEMENT OF THE SECONDARY SURFACE LOW ALONG THE
COAST. THE SHORTWAVE IS EXPECTED TO BE SHEARING OUT AS IT LIFTS
THROUGH THE TN VALLEY REGION...AND THE NAM/GFS ARE STRONGER AND
FASTER THAN THE ECMWF OR CANADIAN...WHOSE LATEST RUNS HAVE COME IN
WITH A MORE MILLER TYPE A SURFACE LOW TRACK (POSSIBLY DUE TO A MORE
SOUTHWARD POSITION OF THE SURFACE HIGH TO OUR NORTH). QPF FORECAST
ALSO SUFFERS FROM THESE DIFFERENCES...BUT THERE SEEMS TO BE A
GENERAL TREND TOWARDS A SPLIT...WITH BEST COVERAGE INITIALLY WITH
THE UPPER WAVE AND ISENTROPIC LIFT IN THE WEST...SHIFTING TO THE
EAST AS THE SECONDARY LOW DEVELOPS OFF THE SAVANNAH COAST SUNDAY
NIGHT AND TRACKS NORTH SOMEWHERE ALONG THE COAST. FOR NOW...WILL
NOT MAKE MANY CHANGES TO THE CURRENT FORECAST...WITH POPS INCREASING
TO LIKELY AFTER 12Z SUNDAY...WITH THE HIGHEST POPS SHIFTING TO THE
EAST AFTER 00Z MONDAY. AS MENTIONED IN EARLIER DISCUSSIONS...THE
CURRENT FORECAST TRACK OF THE COASTAL LOW KEEPS THE CWA ON THE COOL
SIDE OF THE COASTAL FRONT AND THUS VOID OF ANY SURFACE BASED
CONVECTION. HIGHS SUNDAY WILL VARY WIDELY FROM THE COOL CAD AIRMASS
IN THE WEST WHERE MID TO UPPER 40S ARE POSSIBLE...TO WARMER UPPER
50S TO EVEN 60 IN THE SE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 305 AM FRIDAY...
MID LEVEL DRY AIR WILL BRING RAIN TO AN END FROM SW TO NE ON MONDAY
AS A SURFACE HIGH BUILDS ACROSS THE SE US AND WILL HAVE ALL POPS OUT
OF THE CWA BY 00Z TUESDAY. FORECAST LOW LEVEL THICKNESSES CLIMB
20-30M ON MONDAY WITH A WELL MODIFIED HIGH TAKING HOLD. A SLOWER
TRACK OF A COASTAL LOW COULD KEEP CLOUD COVER IN LONGER....A
REINFORCED NORTHERLY FLOW OVER THE AREA... AND HIGHS COOLER. PREFER
A BLEND OF GUIDANCE...59-66 NW-SE.
SURFACE HIGH PRESSURE RIDGE SETTLES OVER THE AREA TUESDAY MORNING
WHICH COULD LEAD TO FOG ISSUES DEPENDING ON ANTECEDENT RAINFALL.
OTHERWISE...TUES LOOKS TO BE A NICE DAY WITH THE NEXT WEATHER SYSTEM
REMAINING WEST OF THE MOUNTAINS. MORNING LOWS COOL IN THE LOW TO
MID 40S. HIGHS IN THE LOW TO MID 60S...JUST ABOVE NORMAL.
MODELS HAVE YET TO SHOW SIGNS OF CONVERGING ON A SOLUTION FOR A
POTENTIAL UPPER LOW OVER THE UPPER MIDWEST BY WEDNESDAY...WITH ITS
COLD FRONT CROSSING THE MOUNTAINS BY WED NIGHT. THE FRONT WOULD BE
WELL SEPARATED FROM ITS PARENT LOW...AND LIKELY VOID OF MUCH
PRECIP. BEHIND THE FRONT...GUIDANCE IS SLOW TO SHOW MUCH AIRMASS
CHANGE...UNTIL A SECOND POTENTIAL CLIPPER SHORTWAVE DIVES SOUTHEAST
THROUGH THE MIDWEST AND INTO THE MID ATLANTIC ON THURS...BRINGING A
SURGE OF COLDER AND DRIER AIR BEHIND IT. CURRENT FORECAST WILL
REMAIN DRY WITH TEMPS FALLING TO BELOW NORMAL BY THEN END OF THE
PERIOD.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 645 AM FRIDAY...
FOG HAS BEGUN TO LIFT/DISSIPATE AS DRIER AIR HAS ADVECTED INTO THE
REGION. EXPECT ANY POCKETS OF FOG TO DISSIPATE BY 14Z. EXPECT
CLEAR/MOSTLY CLEAR SKIES ACROSS MOST OF THE REGION THROUGH 00Z
SATURDAY. EXPECTED WILL BE THE FAR EASTERN PERIPHERY OF THE FORECAST
REGION AND THE KRWI TERMINAL WHERE A DECK OF STRATUS 1500-2500FT MAY
OCCUR HAS A RESULT OF MOISTURE ADVECTION AT THE 925MB LEVEL FROM
THE N-NE. MAY SEE SCATTERED CLOUDS AT THIS LEVEL IN THE RDU VICINITY
BUT NOT EXPECTING CEILINGS THAT FAR WEST. OTHERWISE BRISK N-NE FLOW
WILL INFREQUENTLY GUST BETWEEN 14-18KTS THROUGH 20Z. AFTER
20Z...INFLUENCE OF SURFACE RIDGE WILL CAUSE WINDS TO GRADUALLY
SUBSIDE.
VFR CONDITIONS WILL PERSIST TONIGHT INTO SATURDAY WITH ONLY
PATCHES OF HIGH CLOUDS EXPECTED AND WINDS RELATIVELY LIGHT AND
VARIABLE. MAY SEE POCKETS OF MVFR FOG TOWARD 12Z SATURDAY.
A STORM SYSTEM WILL APPROACH FROM THE SW SATURDAY NIGHT AND AFFECT
THE REGION SUNDAY THROUGH MONDAY MORNING...BRINGING MVFR OR IFR
CONDITIONS.
VFR CONDITIONS RETURN TO THE AREA LATE MONDAY AND PERSIST INTO
TUESDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS/SMITH
LONG TERM...SMITH
AVIATION...WSS
000
FXUS62 KILM 201143
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
643 AM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHWEST THROUGH
SATURDAY. LOW PRESSURE EMERGING FROM THE GULF OF MEXICO WILL BRING
RAIN TO THE EASTERN CAROLINAS SUNDAY THROUGH EARLY MONDAY...PULLING
AWAY TO THE NORTHEAST BY MONDAY AFTERNOON. MILD WEATHER CONDITIONS
CAN BE EXPECTED MUCH OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM FRIDAY...VAPOR IMAGERY FROM SPACE THIS MORNING SHOWS
A BROAD BUT FILLING UPPER LOW PICKING UP FORWARD SPEED ACROSS THE
GREAT LAKES...BUT LOOSENING IT INFLUENCE ON THE COLUMN WINDS
ACROSS OUR FORECAST AREA. IR CHANNEL SHOWS DEEP CONVECTION
ERUPTING ALONG THE TEXAS COAST UPSTREAM WHERE CYCLOGENESIS WAS
GEARING UP. 11U-3.9U CHANNEL SHOWS EXTENSIVE FOG OVER OUR REGION
AS CLEARING HAS TEAMED WITH A VERY DAMP BOUNDARY LAYER AND MOIST
SOILS. 1/4SM VSBYS NOT WIDESPREAD BUT WILL NOT DROP ACTIVE DFA
UNTIL AN 8Z-10Z TREND IS OBSERVED PRIOR TO 600 AM ISSUANCES.
A COLD FRONT HAS MOVED OFFSHORE AND ORIENTED NORTH TO SOUTH STILL
CLIPPED PORTIONS OF THE OUTER BANKS WHERE SATELLITE ESTIMATED
PLUMES OF HIGHER PRECIPITABLE WATERS LURKED JUST OFFSHORE. OUR
PRECIPITATION CHANCES HAVE ENDED OVER LAND. VAD WIND PROFILE SHOWS
A 3000 FOOT DEEP LAYER ON POST-FRONTAL NORTHERLY WIND FLOW. THIS
FLOW SHOULD DEEPEN A BIT MORE ACCOMPANIED BY MODERATE WIND SPEEDS.
THIS SHOULD BE ADEQUATE TO ERODE A GOOD PORTION OF THE STRATUS/FOG
LAYER BY LATE MORNING...WITH SOME AFTERNOON CUMULUS. WITH ONLY
WEAK COLD AIR ADVECTION BEHIND THIS FRONT...AND AFTERNOON BEAMS
OF DEL SOL...THINK MANY SPOTS WILL FLIRT WITH 70 DEGREE MARK.
QUIET OVERNIGHT IN MODERATE BUT SHALLOW NE WIND FLOW AND VERY DRY
AIR ABOVE 4000 FEET. IF WINDS COULD DECOUPLE ENOUGH TONIGHT...FOG
MAY RETURN BUT NOT AS DENSE OR WIDESPREAD AS WE SEE CURRENTLY.
MAINLY CLEAR SKIES TONIGHT SHOULD ALLOW LOWS BY DAYBREAK TO DIP
INTO THE 40S TO KICK-OFF SATURDAY.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...WILL CONTINUE THE TREND OF SLOWING DOWN A
COMPLEX STORM SYSTEM THAT WILL LIFT OUT OF THE GULF THIS WEEKEND.
IT NOW APPEARS THAT THE CWA WILL REMAIN DRY FOR ALL OF SATURDAY
AND INTO SATURDAY EVENING. MAX TEMPS NEAR NORMAL FOR THIS TIME OF
YEAR...LIMITED MAINLY BY INCREASING HIGH CLOUDS AHEAD OF THE LOW
DEVELOPING ALONG THE GULF COAST.
LATEST NAM AND GFS ARE NOW DEPICTING MILLER TYPE-B CYCLOGENESIS AS
WE HEAD INTO SUNDAY...BUT AT THIS POINT THINK THE MAIN POINT IS
THAT IT WILL HAPPEN MORE SLOWLY. ENOUGH DRY AIR FROM 850-750MB
THAT IT WILL TAKE MOST OF SATURDAY NIGHT TO OVERCOME...SO HAVE
TAPERED POPS FROM HIGH CHANCE IN THE SOUTH TO LOW CHANCE IN THE
NORTH. WENT WITH LIKELY SUNDAY INTO SUNDAY NIGHT AS THE MOISTURE
FEED BECOMES WELL ESTABLISHED AROUND 12Z SUN...AND PERSISTS BEYOND
00Z MON. THERE IS CERTAINLY AN ARGUMENT TO BE MADE FOR A RAPID
SHUTOFF IN THE PRECIP SUN NIGHT...BUT NOT GETTING TOO CUTE WITH
THE TIMING THIS FAR OUT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...DRY WEATHER PATTERN IN STORE FOR THE
EXTENDED...WITH CHILLY AIR KNOCKING ON THE DOOR BY THE END. SFC
RIDGING ALONG THE GULF COAST AND A FLAT UPPER PATTERN WILL KEEP
TEMPS MILD...WITH HIGHS CLOSE TO 70 MON-WED AND LOWS ALSO A
CATEGORY OR TWO ABOVE CLIMO. BY THURSDAY LOOK FOR A FULL-LATITUDE
TROUGH TO SETTLE IN ALONG THE EAST COAST. HARD TO TIME THE
ASSOCIATED COLD FRONT...BUT REGARDLESS IT LOOKS TO BE MOISTURE-
STARVED...SO NO POPS WILL BE INCLUDED AT THIS TIME. DAYTIME TEMPS
NEAR NORMAL FOR TURKEY DAY...AS THE CHILLY AIR HOLDS OFF UNTIL
BEYOND THE VALID PERIOD OF THE ZONE FORECAST.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
COLD FRONT LOCATED JUST OFFSHORE WILL SLOWLY PULL FURTHER EAST TODAY
BRINGING MODERATE N/NE WINDS AND CLEARING SKY CONDITIONS TO THE
TERMINALS.
LIFR FOG AGAIN OCCURRING AT FLO THIS MORNING...WITH IFR AT LBT...AND
MVFR AT ILM. ALL OF THIS FOG WILL BURN OFF BY 14Z...AND INCREASING
NORTH WINDS WILL HELP SCOUR OUT ANY REMAINING IFR STRATUS. THE
LOWEST LEVELS OF THE ATMOSPHERIC COLUMN ARE STILL QUITE MOIST...SO
EXPECT SOME SCT LOW LEVEL STRATUS TO HANG AROUND THROUGH THE
MORNING. VFR VSBYS AND CIGS WILL BE THE RULE AT ALL TERMINALS AFTER
14Z TODAY EVEN WITH THE LOW STRATUS. THIS AFTN SOME STRATOCU MAY
DEVELOP AROUND 2500 FEET. SOME OF THE GUIDANCE IS SUGGESTING THAT A
BKN CIG MAY DEVELOP THIS AFTN...BUT WITH SUBSIDENCE BEHIND THE FRONT
HAVE ONLY PUT SCT IN THE TAFS. ANY CU WILL BE VERY SHALLOW THOUGH AS
MID LEVELS ARE VERY DRY. WINDS WILL BE AROUND 8 TO 12 KT FROM THE
N/NE AS MIXING WILL ALLOW SOME HIGHER SPEEDS TODAY. TONIGHT...MOSTLY
CLEAR SKY CONDITIONS WITH ONLY SOME HIGH CIRRUS OR LEFTOVER STRATOCU
AT THE TERMINALS. IF WINDS CAN DECOUPLE TONIGHT THERE MAY BE SOME
LIGHT FOG AT LBT/FLO...BUT NOTHING LIKE WHAT HAS OCCURRED THE
PREVIOUS 2 DAYS.
EXTENDED OUTLOOK...VFR SATURDAY. SHOWERS AND LOW CEILINGS SUNDAY
THROUGH MONDAY. FOG POSSIBLE TUESDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM FRIDAY...NORTHERLY WIND FLOW OVER THE WATERS AS A COLD
FRONT PUSHES FARTHER TO SEA. WAVE ENERGY WAS SPREAD OUT NEARLY
EQUALLY BETWEEN WAVE PERIODS 4-9 SECONDS...WITH NORTHERLY WIND-
WAVES AND UNDERLYING ESE SWELL ENERGY PROPAGATING TOWARD
SHORE...SO PRETTY DOGGONE BUMPY. PERSISTENT FETCH BEYOND THE COLD
FRONT WILL MAINTAIN ONSHORE WAVE ENERGY INTO THE CAROLINA SHORES
IN THE 7-9 SECOND PERIOD RANGE FOR THE NEXT FEW DAYS. THIS COUPLED
WITH NE SURFACE WINDS WILL SUSTAIN BUMPY BOATING CONDITIONS INTO
THE WEEKEND.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...EXPECT STATUS QUO WITH NE WINDS SATURDAY AND
SATURDAY NIGHT. FOR NOW WILL KEEP SPEEDS AROUND 15 KT...BUT THE
GRADIENT APPEARS TO TIGHTEN BY SUNDAY MORNING. COULD SEE A SOLID
20 KT...AND THE NE FETCH WILL BE PERSISTENT ENOUGH TO GENERATE
SOME 6 FT SEAS ALONG FRYING PAN SHOALS AND OFF CAPE ROMAIN. NOT
NEARLY AS MUCH FETCH TO WORK WITH NEAR SHORE...SO LOOK FOR A MUCH
MORE MODEST 2-3 FT THERE.
SUNDAY NIGHT IS THE LOW CONFIDENCE PORTION OF THE FORECAST. LATEST
NAM AND GFS NOW TRY TO PULL THE LOW IN OVER LAND AS IT CROSSES
EASTERN NC. NOT SOLD ENOUGH ON THIS SOLUTION JUST YET...SO WILL
REMAIN CLOSE TO THE PREVIOUS FORECAST WHICH MAINTAINS AN OFFSHORE
TRACK. WILL BRING THE LOW CLOSE ENOUGH TO SEE A VEERING TO ENE
AHEAD OF IT...AND BACKING TO NW AS THE LOW DEPARTS. LOOK FOR A
DIMINISHING TREND IN WINDS DUE TO PROXIMITY OF THE LOW...AND SEAS
GENERALLY IN THE 3-4 FT RANGE FOR MUCH OF THE NIGHT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...WILL START OFF MONDAY WITH NW WINDS BEHIND
DEPARTING LOW PRESSURE. WITH THE HIGH BUILDING FROM THE GULF COAST
AND FLAT RIDGING ALOFT...WOULD NOT EXPECT ANY COLD AIR SURGE...SO
WIND SPEEDS WILL REMAIN QUITE TAME...AROUND 10 KT. COULD SEE WINDS
BACK AROUND TO WESTERLY ON TUESDAY AS THE SFC RIDGE IS SUPPRESSED
A LITTLE FARTHER SOUTH...AND A NORTHERN STREAM IMPULSE SCOOTS
QUICKLY INTO THE MID-ATLANTIC STATES. SEAS 2-4 FT TO BEGIN
WITH...BUT SUBSIDING TO AROUND 2 FT THROUGHOUT IN THE LIGHT
OFFSHORE FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE
NC...NONE
MARINE...NONE.
&&
$$
NEAR TERM....MIKE
SHORT TERM...RON
LONG TERM....RON
AVIATION.....JOSH
000
FXUS62 KRAH 201105
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
605 AM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO CENTRAL NORTH CAROLINA TODAY AND
SETTLE OVERHEAD TONIGHT. THE HIGH WILL DRIFT EAST SATURDAY...IN
ADVANCE OF THE NEXT STORM SYSTEM EXPECTED TO EFFECT THE REGION
SUNDAY AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 605 AM FRIDAY...
CANCELED DENSE FOG ADVISORY. WHILE WIDESPREAD FOG
OCCURRING...VISIBILITIES MAINLY AT OR ABOVE MILE WITH JUST POCKETS
WHERE THE VISIBILITY IS A HALF MILE OR LESS. VISIBILITIES WILL
IMPROVE RAPIDLY WITHIN AN HOUR OR TWO AFTER SUNRISE.
OTHERWISE HIGH PRESSURE WILL BUILD INTO THE FORECAST AREA TODAY.
EXPECT STEADY NLY BREEZE AFTER SUNRISE WITH INFREQUENT GUSTS THIS
MORNING BETWEEN 15-20KTS. ASIDE FROM A FEW-SCATTERED CLOUDS AROUND
2000FT...EXPECT A LOT OF SUN TODAY. THICKNESSES WITH FULL SUN
SUPPORT TEMPS IN THE LOW/MID 60S WITH UPPER 60S POSSIBLE SE. MOS
GUIDANCE SIMILAR AS WELL AS PREVIOUS FORECAST SO SEE LITTLE NEED TO
ADJUST.
TONIGHT...MODEL RH PROFILE CONTINUE TO DEPICT RETURN OF HIGH LEVEL
MOISTURE IN ADVANCE OF SOUTHERN STREAM S/W. STILL SOME UNCERTAINTY
AS TO OPAQUENESS OF HIGH CLOUDS THOUGH AND MOS GUIDANCE KEEP SKY
COVERAGE NO WORSE THAN FEW. THUS SHOULD SEE DECENT NOCTURNAL COOLING
CONDITIONS TONIGHT. IF TOP SOIL WAS NOT SO SATURATED...COULD SEE
TEMPS LOWER INTO THE LOW AND MID 30S. HOWEVER RESIDUAL LOW LEVEL
MOISTURE WILL MAINTAIN SOME WARMTH NEAR THE SURFACE SO EXPECT MIN
TEMPS UPPER 30S NEAR 40 NW TO MID 40S SE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 315 AM FRIDAY...
MID/UPPER LEVEL MOISTURE INCREASES AND DEEPENS SATURDAY IN SW FLOW
OVERHEAD IN ADVANCE OF SOUTHERN STREAM SYSTEM IN THE NW GULF.
MEANWHILE PARENT SURFACE HIGH MIGRATES FROM THE LOWER OH VALLEY
TOWARD THE EASTERN LAKES WITH RIDGE EXTENDING INTO THE WESTERN
PIEDMONT. THIS WILL RESULT IN A N-NE LOW LEVEL FLOW...ADVECTING
COOL AND RELATIVELY DRY AIR. MAX TEMPS SATURDAY DEPENDENT UPON WHEN
MID/HIGH CLOUDS BECOME OPAQUE ENOUGH TO BLOCK OUT SUN. WILL MAINTAIN
MAX TEMPS AS PER PREVIOUS FORECAST (AROUND 60 NW TO MID 60S SE). IF
GFS CORRECT...SKIES BECOME OVERCAST BY MIDDAY. IF THIS OCCURS...MAX
TEMPS WILL LIKELY BE 3-4 DEGREES COOLER...ESPECIALLY IN THE
WEST.
SATURDAY NIGHT...925-850MB FLOW BACKS AND STRENGTHENS IN RESPONSE TO
APPROACH OF SOUTHERN STREAM LOW PRESSURE SYSTEM LIFTING ACROSS THE
LOWER MS VALLEY. EXPECT CLOUDS TO LOWER THICKEN. ISENTROPIC LIFT
INCREASES TOWARD 12Z IN THE 300-305 LAYER...MORE SO AFTER 12Z. WILL
MAINTAIN DRY CONDITIONS THROUGH 06Z..THEN MAINTAIN CONTINUE PREVIOUS
FORECAST OF INCREASING POPS SW-NE AFTER 06Z. REFRAINED FROM
INCREASING POPS ABOVE 40 PERCENT. RH PROFILES DEPICT RELATIVELY DRY
SUB CLOUD LAYER TILL 12Z SO INITIAL PRECIP WILL GO TOWARD MOISTENING
THIS LAYER. IF MOISTENING OCCURS FASTER THAN EXPECTED THEN COULD SEE
NEED TO INCREASE POPS TO LOW END LIKELY IN THE FAR W-SW. RAISED MIN
TEMPS A FEW DEGREES BASED ON THICKENING CLOUD COVERAGE IN THE WEST.
MIN TEMPS LOWER 40S NE TO MID/UPPER 40S WEST-SOUTH. -WSS
BY 12Z SUNDAY...A SOUTHERN STREAM SHORTWAVE TROUGH IS PROGGED TO
HAVE BECOME NEGATIVELY TILTED...LIFTING FROM THE GULF COAST INTO THE
TN VALLEY REGION. WITH A 1025MB HIGH OVER THE NY/CANADA
BORDER...AND A SURFACE LOW LIFTING NORTHEAST WITH THE
SHORTWAVE...MODELS HAVE BEEN SHOWING A MILLER B TYPE SURFACE
PRESSURE EVOLUTION FOR SUNDAY INTO SUNDAY NIGHT. AS THE SHORTWAVE
AND LOW LIFT NORTHEAST..AND A SOUTHERN STREAM JET IS PULLED
NORTHWARD...UPPER LEVEL DIFFLUENCE WILL INCREASE OVER CENTRAL
NC...AND COMBINED WITH STRENGTHENING 850MB FLOW AND LOW LEVEL WARM
ADVECTION...EXPECT RAIN CHANCES TO INCREASE RAPIDLY SUNDAY MORNING.
THERE ARE STILL SOME INCONSISTENCIES AMONG MODEL GUIDANCE ON THE
STRENGTH OF THE SHORTWAVE AS IT PASSES BY...AND ALSO ON THE TIMING
OF DEVELOPMENT AND MOVEMENT OF THE SECONDARY SURFACE LOW ALONG THE
COAST. THE SHORTWAVE IS EXPECTED TO BE SHEARING OUT AS IT LIFTS
THROUGH THE TN VALLEY REGION...AND THE NAM/GFS ARE STRONGER AND
FASTER THAN THE ECMWF OR CANADIAN...WHOSE LATEST RUNS HAVE COME IN
WITH A MORE MILLER TYPE A SURFACE LOW TRACK (POSSIBLY DUE TO A MORE
SOUTHWARD POSITION OF THE SURFACE HIGH TO OUR NORTH). QPF FORECAST
ALSO SUFFERS FROM THESE DIFFERENCES...BUT THERE SEEMS TO BE A
GENERAL TREND TOWARDS A SPLIT...WITH BEST COVERAGE INITIALLY WITH
THE UPPER WAVE AND ISENTROPIC LIFT IN THE WEST...SHIFTING TO THE
EAST AS THE SECONDARY LOW DEVELOPS OFF THE SAVANNAH COAST SUNDAY
NIGHT AND TRACKS NORTH SOMEWHERE ALONG THE COAST. FOR NOW...WILL
NOT MAKE MANY CHANGES TO THE CURRENT FORECAST...WITH POPS INCREASING
TO LIKELY AFTER 12Z SUNDAY...WITH THE HIGHEST POPS SHIFTING TO THE
EAST AFTER 00Z MONDAY. AS MENTIONED IN EARLIER DISCUSSIONS...THE
CURRENT FORECAST TRACK OF THE COASTAL LOW KEEPS THE CWA ON THE COOL
SIDE OF THE COASTAL FRONT AND THUS VOID OF ANY SURFACE BASED
CONVECTION. HIGHS SUNDAY WILL VARY WIDELY FROM THE COOL CAD AIRMASS
IN THE WEST WHERE MID TO UPPER 40S ARE POSSIBLE...TO WARMER UPPER
50S TO EVEN 60 IN THE SE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 305 AM FRIDAY...
MID LEVEL DRY AIR WILL BRING RAIN TO AN END FROM SW TO NE ON MONDAY
AS A SURFACE HIGH BUILDS ACROSS THE SE US AND WILL HAVE ALL POPS OUT
OF THE CWA BY 00Z TUESDAY. FORECAST LOW LEVEL THICKNESSES CLIMB
20-30M ON MONDAY WITH A WELL MODIFIED HIGH TAKING HOLD. A SLOWER
TRACK OF A COASTAL LOW COULD KEEP CLOUD COVER IN LONGER....A
REINFORCED NORTHERLY FLOW OVER THE AREA... AND HIGHS COOLER. PREFER
A BLEND OF GUIDANCE...59-66 NW-SE.
SURFACE HIGH PRESSURE RIDGE SETTLES OVER THE AREA TUESDAY MORNING
WHICH COULD LEAD TO FOG ISSUES DEPENDING ON ANTECEDENT RAINFALL.
OTHERWISE...TUES LOOKS TO BE A NICE DAY WITH THE NEXT WEATHER SYSTEM
REMAINING WEST OF THE MOUNTAINS. MORNING LOWS COOL IN THE LOW TO
MID 40S. HIGHS IN THE LOW TO MID 60S...JUST ABOVE NORMAL.
MODELS HAVE YET TO SHOW SIGNS OF CONVERGING ON A SOLUTION FOR A
POTENTIAL UPPER LOW OVER THE UPPER MIDWEST BY WEDNESDAY...WITH ITS
COLD FRONT CROSSING THE MOUNTAINS BY WED NIGHT. THE FRONT WOULD BE
WELL SEPARATED FROM ITS PARENT LOW...AND LIKELY VOID OF MUCH
PRECIP. BEHIND THE FRONT...GUIDANCE IS SLOW TO SHOW MUCH AIRMASS
CHANGE...UNTIL A SECOND POTENTIAL CLIPPER SHORTWAVE DIVES SOUTHEAST
THROUGH THE MIDWEST AND INTO THE MID ATLANTIC ON THURS...BRINGING A
SURGE OF COLDER AND DRIER AIR BEHIND IT. CURRENT FORECAST WILL
REMAIN DRY WITH TEMPS FALLING TO BELOW NORMAL BY THEN END OF THE
PERIOD.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1230 AM FRIDAY...
WIDESPREAD LIFR VISIBILITIES EXPECTED THROUGH 12Z OVER MOST OF
CENTRAL NC AS DRIER AIR ALOFT AS CLEARED OUT CLOUDS. RESIDUAL NEAR
SURFACE MOISTURE HAS ALLOWED FOG AND LOW STRATUS TO DEVELOP. EXPECT
VISIBILITIES AT OR BELOW A MILE WITH VISIBILITIES BELOW A HALF MILE
QUITE COMMON. AS DRIER AIR GRADUALLY MIXES TOWARD THE SURFACE AFTER
09Z...EXPECT VISIBILITIES TO IMPROVE FROM WEST TO EAST.
AFTER 13Z...DRIER AIR THROUGHOUT THE ENTIRE ATMOSPHERE SHOULD RESULT
IN CLEAR OR MOSTLY CLEAR SKIES. NEAR SURFACE WINDS WILL BE NORTHERLY
AROUND 10 KTS WITH INFREQUENT GUSTS 16-19KTS THROUGH 18Z. AS HIGH
PRESSURE BUILDS FARTHER INTO THE REGION...WINDS WILL GRADUALLY
SUBSIDE.
VFR CONDITIONS WILL PERSIST FRIDAY NIGHT INTO SATURDAY WITH ONLY
PATCHES OF HIGH CLOUDS EXPECTED AND WINDS RELATIVELY LIGHT AND
VARIABLE.
A STORM SYSTEM WILL APPROACH FROM THE SW SATURDAY NIGHT AND AFFECT
THE REGION SUNDAY THROUGH MONDAY MORNING...BRINGING MVFR OR IFR
CONDITIONS.
VFR CONDITIONS RETURN TO THE AREA LATE MONDAY AND PERSIST INTO
TUESDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS/SMITH
LONG TERM...SMITH
AVIATION...WSS
000
FXUS62 KILM 201100
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
600 AM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE NORTHWEST THROUGH
SATURDAY. LOW PRESSURE EMERGING FROM THE GULF OF MEXICO WILL BRING
RAIN TO THE EASTERN CAROLINAS SUNDAY THROUGH EARLY MONDAY...PULLING
AWAY TO THE NORTHEAST BY MONDAY AFTERNOON. MILD WEATHER CONDITIONS
CAN BE EXPECTED MUCH OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM FRIDAY...VAPOR IMAGERY FROM SPACE THIS MORNING SHOWS
A BROAD BUT FILLING UPPER LOW PICKING UP FORWARD SPEED ACROSS THE
GREAT LAKES...BUT LOOSENING IT INFLUENCE ON THE COLUMN WINDS
ACROSS OUR FORECAST AREA. IR CHANNEL SHOWS DEEP CONVECTION
ERUPTING ALONG THE TEXAS COAST UPSTREAM WHERE CYCLOGENESIS WAS
GEARING UP. 11U-3.9U CHANNEL SHOWS EXTENSIVE FOG OVER OUR REGION
AS CLEARING HAS TEAMED WITH A VERY DAMP BOUNDARY LAYER AND MOIST
SOILS. 1/4SM VSBYS NOT WIDESPREAD BUT WILL NOT DROP ACTIVE DFA
UNTIL AN 8Z-10Z TREND IS OBSERVED PRIOR TO 600 AM ISSUANCES.
A COLD FRONT HAS MOVED OFFSHORE AND ORIENTED NORTH TO SOUTH STILL
CLIPPED PORTIONS OF THE OUTER BANKS WHERE SATELLITE ESTIMATED
PLUMES OF HIGHER PRECIPITABLE WATERS LURKED JUST OFFSHORE. OUR
PRECIPITATION CHANCES HAVE ENDED OVER LAND. VAD WIND PROFILE SHOWS
A 3000 FOOT DEEP LAYER ON POST-FRONTAL NORTHERLY WIND FLOW. THIS
FLOW SHOULD DEEPEN A BIT MORE ACCOMPANIED BY MODERATE WIND SPEEDS.
THIS SHOULD BE ADEQUATE TO ERODE A GOOD PORTION OF THE STRATUS/FOG
LAYER BY LATE MORNING...WITH SOME AFTERNOON CUMULUS. WITH ONLY
WEAK COLD AIR ADVECTION BEHIND THIS FRONT...AND AFTERNOON BEAMS
OF DEL SOL...THINK MANY SPOTS WILL FLIRT WITH 70 DEGREE MARK.
QUIET OVERNIGHT IN MODERATE BUT SHALLOW NE WIND FLOW AND VERY DRY
AIR ABOVE 4000 FEET. IF WINDS COULD DECOUPLE ENOUGH TONIGHT...FOG
MAY RETURN BUT NOT AS DENSE OR WIDESPREAD AS WE SEE CURRENTLY.
MAINLY CLEAR SKIES TONIGHT SHOULD ALLOW LOWS BY DAYBREAK TO DIP
INTO THE 40S TO KICK-OFF SATURDAY.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...WILL CONTINUE THE TREND OF SLOWING DOWN A
COMPLEX STORM SYSTEM THAT WILL LIFT OUT OF THE GULF THIS WEEKEND.
IT NOW APPEARS THAT THE CWA WILL REMAIN DRY FOR ALL OF SATURDAY
AND INTO SATURDAY EVENING. MAX TEMPS NEAR NORMAL FOR THIS TIME OF
YEAR...LIMITED MAINLY BY INCREASING HIGH CLOUDS AHEAD OF THE LOW
DEVELOPING ALONG THE GULF COAST.
LATEST NAM AND GFS ARE NOW DEPICTING MILLER TYPE-B CYCLOGENESIS AS
WE HEAD INTO SUNDAY...BUT AT THIS POINT THINK THE MAIN POINT IS
THAT IT WILL HAPPEN MORE SLOWLY. ENOUGH DRY AIR FROM 850-750MB
THAT IT WILL TAKE MOST OF SATURDAY NIGHT TO OVERCOME...SO HAVE
TAPERED POPS FROM HIGH CHANCE IN THE SOUTH TO LOW CHANCE IN THE
NORTH. WENT WITH LIKELY SUNDAY INTO SUNDAY NIGHT AS THE MOISTURE
FEED BECOMES WELL ESTABLISHED AROUND 12Z SUN...AND PERSISTS BEYOND
00Z MON. THERE IS CERTAINLY AN ARGUMENT TO BE MADE FOR A RAPID
SHUTOFF IN THE PRECIP SUN NIGHT...BUT NOT GETTING TOO CUTE WITH
THE TIMING THIS FAR OUT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...DRY WEATHER PATTERN IN STORE FOR THE
EXTENDED...WITH CHILLY AIR KNOCKING ON THE DOOR BY THE END. SFC
RIDGING ALONG THE GULF COAST AND A FLAT UPPER PATTERN WILL KEEP
TEMPS MILD...WITH HIGHS CLOSE TO 70 MON-WED AND LOWS ALSO A
CATEGORY OR TWO ABOVE CLIMO. BY THURSDAY LOOK FOR A FULL-LATITUDE
TROUGH TO SETTLE IN ALONG THE EAST COAST. HARD TO TIME THE
ASSOCIATED COLD FRONT...BUT REGARDLESS IT LOOKS TO BE MOISTURE-
STARVED...SO NO POPS WILL BE INCLUDED AT THIS TIME. DAYTIME TEMPS
NEAR NORMAL FOR TURKEY DAY...AS THE CHILLY AIR HOLDS OFF UNTIL
BEYOND THE VALID PERIOD OF THE ZONE FORECAST.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
LOOKS LIKE FOG/STRATUS WILL SET UP OVER MOST OF THE REGION
TONIGHT...WITH POTENTIALLY LOW VISIBILITIES. ATMOSPHERE SHOULD MIX
OUT FAIRLY QUICKLY TOMORROW WITH VFR EXPECTED AT ALL TERMINALS BY
MID MORNING. HIGH PRESSURE WILL CONTINUE TO BUILD IN ALL DAY WITH A
NORTH NORTHEAST WIND...A BIT GUSTY IN THE AFTERNOON.
EXTENDED OUTLOOK...VFR FRIDAY/SATURDAY. SHOWERS AND LOW CEILINGS
MOVE BACK IN SATURDAY NIGHT THROUGH MONDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM FRIDAY...NORTHERLY WIND FLOW OVER THE WATERS AS A COLD
FRONT PUSHES FARTHER TO SEA. WAVE ENERGY WAS SPREAD OUT NEARLY
EQUALLY BETWEEN WAVE PERIODS 4-9 SECONDS...WITH NORTHERLY WIND-
WAVES AND UNDERLYING ESE SWELL ENERGY PROPAGATING TOWARD
SHORE...SO PRETTY DOGGONE BUMPY. PERSISTENT FETCH BEYOND THE COLD
FRONT WILL MAINTAIN ONSHORE WAVE ENERGY INTO THE CAROLINA SHORES
IN THE 7-9 SECOND PERIOD RANGE FOR THE NEXT FEW DAYS. THIS COUPLED
WITH NE SURFACE WINDS WILL SUSTAIN BUMPY BOATING CONDITIONS INTO
THE WEEKEND.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...EXPECT STATUS QUO WITH NE WINDS SATURDAY AND
SATURDAY NIGHT. FOR NOW WILL KEEP SPEEDS AROUND 15 KT...BUT THE
GRADIENT APPEARS TO TIGHTEN BY SUNDAY MORNING. COULD SEE A SOLID
20 KT...AND THE NE FETCH WILL BE PERSISTENT ENOUGH TO GENERATE
SOME 6 FT SEAS ALONG FRYING PAN SHOALS AND OFF CAPE ROMAIN. NOT
NEARLY AS MUCH FETCH TO WORK WITH NEAR SHORE...SO LOOK FOR A MUCH
MORE MODEST 2-3 FT THERE.
SUNDAY NIGHT IS THE LOW CONFIDENCE PORTION OF THE FORECAST. LATEST
NAM AND GFS NOW TRY TO PULL THE LOW IN OVER LAND AS IT CROSSES
EASTERN NC. NOT SOLD ENOUGH ON THIS SOLUTION JUST YET...SO WILL
REMAIN CLOSE TO THE PREVIOUS FORECAST WHICH MAINTAINS AN OFFSHORE
TRACK. WILL BRING THE LOW CLOSE ENOUGH TO SEE A VEERING TO ENE
AHEAD OF IT...AND BACKING TO NW AS THE LOW DEPARTS. LOOK FOR A
DIMINISHING TREND IN WINDS DUE TO PROXIMITY OF THE LOW...AND SEAS
GENERALLY IN THE 3-4 FT RANGE FOR MUCH OF THE NIGHT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...WILL START OFF MONDAY WITH NW WINDS BEHIND
DEPARTING LOW PRESSURE. WITH THE HIGH BUILDING FROM THE GULF COAST
AND FLAT RIDGING ALOFT...WOULD NOT EXPECT ANY COLD AIR SURGE...SO
WIND SPEEDS WILL REMAIN QUITE TAME...AROUND 10 KT. COULD SEE WINDS
BACK AROUND TO WESTERLY ON TUESDAY AS THE SFC RIDGE IS SUPPRESSED
A LITTLE FARTHER SOUTH...AND A NORTHERN STREAM IMPULSE SCOOTS
QUICKLY INTO THE MID-ATLANTIC STATES. SEAS 2-4 FT TO BEGIN
WITH...BUT SUBSIDING TO AROUND 2 FT THROUGHOUT IN THE LIGHT
OFFSHORE FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE
NC...NONE
MARINE...NONE.
&&
$$
NEAR TERM....MIKE
SHORT TERM...RON
LONG TERM....RON
AVIATION.....MIKE/JOSH
000
FXUS62 KMHX 201048
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
545 AM EST FRI NOV 20 2009
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE OFFSHORE TODAY. HIGH PRES WILL BUILD
IN FROM THE N TONIGHT AND SAT...THEN SLIDE OFFSHORE SAT NIGHT. LOW
PRES WILL APPROACH FROM THE SW SUNDAY AND MOVE NE NEAR OR JUST
OFFSHORE OF THE COAST SUN NIGHT INTO MON. HIGH PRESSURE WILL
REBUILD OVER THE AREA TUESDAY THROUGH LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATED TO DROP DENSE FOG ADVISORY.
PREVIOUS DISCUSSION...
AS OF 230 AM FRIDAY...WEAK BOUNDARY IS SLOWLY APPROACHING THE COAST
WITH SOME ISOLD SHRA OVER NRN TIER AND CSTL WTRS. MDLS SHOW BEST
CHCS OF SHRA ALONG IMD CST AFTER 12Z SO KEPT SMALL POP IN THESE
AREA THROUGH THE MORNING. WIDESPREAD CLOUD COVER OVER THE REGION
HAS LIMITED FOG DEVELOPMENT SO FAR TONIGHT. WITH BOUNDARY MOVING
SLOWLY EXPECT CLOUDS TO LINGER MOST AREAS THROUGH DAY BREAK AND
THIS WILL LIMIT POTENTIAL FOR WIDESPREAD DENSE FOG. WILL CONT TO
MONITOR NEXT CPL HOURS BUT LOOKS LIKE WILL BE ABLE TO DROP DENSE
FOG ADVISORY EARLY. WITH SOME SUNSHINE DEVELOPING TODAY SHLD SEE
HIGHS IN THE MID TO UPR 60S.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 230 AM FRIDAY...HIGH PRESSURE WILL BUILD N OF THE REGION
TONIGHT AND SAT WITH DRY WEATHER. SHLD HAVE GOOD RADIATIONAL
COOLING TONIGHT WITH LOWS IN THE LOW TO MID 40S COOLER INLAND
SPOTS. HIGHS SAT WITH PLENTY OF SUN SHLD REACH THE LOW TO MID 60S.
AS HIGH MOVES OFFSHORE TO THE N SAT NIGHT WILL SEE INCREASING
MOISTURE AS LOW LVL FLOW BECOMES MORE ONSHORE. OVERALL ATMS IS DRY
TO START SO NOT LOOKING FOR MUCH RAIN TO DEVELOP SAT
NIGHT...MAINLY LATE NEAR THE COAST. APPROACHING SRT WAVE COMBINED
WITH INCREASING ISENT LIFT SHLD LEAD TO DECENT CVRG OF RAIN SUNDAY
INTO SUNDAY NIGHT. FOR NOW WILL LEAN MORE TWRD NAM/EMCWF KEEPING
MAINLY NE FLOW OVER THE REGION WITH LOW PRES NEAR OR JUST OFF THE
CST LATER SUN INTO MON. THIS WILL ALSO KEEP RAIN THREAT GOING
LONGER THAN PREV FCST INDICATED SO INCREASED POPS TO LIKELY SUN
NIGHT ALL AREAS AND CONT LIKELY INTO MON MORN OVER THE ERN HALF OF
THE AREA. CLOUDS AND PRECIP WILL LIMIT HIGHS TO LOW TO POSS MID
60S SUNDAY AND MON.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...HIGH PRES WILL BUILD IN TUE AND WED WITH DRY
WEATHER. COLD FRONT EXPECTED TO CROSS LATER WED OR EARLY THU AND
MAY SEE SOME RAIN FROM THIS BUT WILL NOT CHANGE CURRENT DRY FCST
UNTIL HAVE MORE CONFIDENCE.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
LIGHT WINDS AND MOIST LOW LVLS LEADING TO WDSPRD IFR CIGS EARLY THIS
MORNING WITH MAINLY MVFR VSBYS. FRONT WILL PUSH OFFSHORE EARLY THIS
MORNING BUT NO STRONG DRYING BEHIND IT AND MODEL RH XSCTNS INDICATE
CIGS LIFTING BUT NOT SCATTERING OUT UNTIL AFTN. ENOUGH DRYING
TONIGHT FOR VFR.
VFR CONTINUING SAT-SUN WITH HIGH PRES EXTENDING IN...THEN CONDITIONS
LOWERING SUN NIGHT-MON WITH LOW PRES MOVING ACROSS. CONDITIONS
IMPROVING AGAIN MON NIGHT-TUE WITH HIGH PRES AGAIN.
&&
.MARINE...
FRONT MOVING ACROSS WATERS EARLY THIS MORNING AND CAA SURGE TO
AROUND SCA SPEEDS EXPECTED BEHIND IT DURING THE DAY. NW-N WINDS WILL
INCREASE FIRST OVER SRN WATERS EARLY THIS MORNING BUT MAIN SURGE
WILL DEVELOPE MID-MORNING OVER NRN WATERS AND SPREAD S THROUGH EARLY
AFTN. KEPT SPEEDS AT 15-20 KTS ALL WATERS BUT MENTIONED GUSTS TO 25
KT OUTER WATERS. SEAS MAY DROP BELOW 6 FT BRIEFLY THIS MORNING FOR
NRN AND CENTRAL WATERS BUT WILL INCREASE QUICKLY WITH SURGE...THUS
KEPT SCA IN PLACE. DID DROP SCA EARLY FOR SRN WATERS BUT STARTED IT
AGAIN LATE AFTN.
MODERATE NE WINDS AND HIGHER SEAS WILL PERSIST TONIGHT INTO SAT. LOW
CONFIDENCE FCST WITH NEXT LOW PRES SYSTEM AFFECTING AREA LATE SUN
INTO MON AND DID NOT MAKE SIGNIFICANT CHANGE TO PREVIOUS
FCST...KEEPING LOW TRACK OFFSHORE. MODELS ARE TRENDING MORE TOWARD
MOVEMENT ALONG COAST BUT WILL LET DAY SHIFT TAKE A LOOK.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST SATURDAY NIGHT FOR
AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR AMZ156.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ150.
SMALL CRAFT ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
AMZ158.
&&
$$
SYNOPSIS...RF
NEAR TERM...RF
SHORT TERM...RF
LONG TERM...RF
AVIATION...JBM
MARINE...JBM
000
FXUS62 KMHX 200933
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
430 AM EST FRI NOV 20 2009
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE OFFSHORE TODAY. HIGH PRES WILL BUILD
IN FROM THE N TONIGHT AND SAT...THEN SLIDE OFFSHORE SAT NIGHT. LOW
PRES WILL APPROACH FROM THE SW SUNDAY AND MOVE NE NEAR OR JUST
OFFSHORE OF THE COAST SUN NIGHT INTO MON. HIGH PRESSURE WILL
REBUILD OVER THE AREA TUESDAY THROUGH LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 230 AM FRIDAY...WEAK BOUNDARY IS SLOWLY APPROACHING THE COAST
WITH SOME ISOLD SHRA OVER NRN TIER AND CSTL WTRS. MDLS SHOW BEST
CHCS OF SHRA ALONG IMD CST AFTER 12Z SO KEPT SMALL POP IN THESE
AREA THROUGH THE MORNING. WIDESPREAD CLOUD COVER OVER THE REGION
HAS LIMITED FOG DEVELOPMENT SO FAR TONIGHT. WITH BOUNDARY MOVING
SLOWLY EXPECT CLOUDS TO LINGER MOST AREAS THROUGH DAY BREAK AND
THIS WILL LIMIT POTENTIAL FOR WIDESPREAD DENSE FOG. WILL CONT TO
MONITOR NEXT CPL HOURS BUT LOOKS LIKE WILL BE ABLE TO DROP DENSE
FOG ADVISORY EARLY. WITH SOME SUNSHINE DEVELOPING TODAY SHLD SEE
HIGHS IN THE MID TO UPR 60S.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 230 AM FRIDAY...HIGH PRESSURE WILL BUILD N OF THE REGION
TONIGHT AND SAT WITH DRY WEATHER. SHLD HAVE GOOD RADIATIONAL
COOLING TONIGHT WITH LOWS IN THE LOW TO MID 40S COOLER INLAND
SPOTS. HIGHS SAT WITH PLENTY OF SUN SHLD REACH THE LOW TO MID 60S.
AS HIGH MOVES OFFSHORE TO THE N SAT NIGHT WILL SEE INCREASING
MOISTURE AS LOW LVL FLOW BECOMES MORE ONSHORE. OVERALL ATMS IS DRY
TO START SO NOT LOOKING FOR MUCH RAIN TO DEVELOP SAT
NIGHT...MAINLY LATE NEAR THE COAST. APPROACHING SRT WAVE COMBINED
WITH INCREASING ISENT LIFT SHLD LEAD TO DECENT CVRG OF RAIN SUNDAY
INTO SUNDAY NIGHT. FOR NOW WILL LEAN MORE TWRD NAM/EMCWF KEEPING
MAINLY NE FLOW OVER THE REGION WITH LOW PRES NEAR OR JUST OFF THE
CST LATER SUN INTO MON. THIS WILL ALSO KEEP RAIN THREAT GOING
LONGER THAN PREV FCST INDICATED SO INCREASED POPS TO LIKELY SUN
NIGHT ALL AREAS AND CONT LIKELY INTO MON MORN OVER THE ERN HALF OF
THE AREA. CLOUDS AND PRECIP WILL LIMIT HIGHS TO LOW TO POSS MID
60S SUNDAY AND MON.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...HIGH PRES WILL BUILD IN TUE AND WED WITH DRY
WEATHER. COLD FRONT EXPECTED TO CROSS LATER WED OR EARLY THU AND
MAY SEE SOME RAIN FROM THIS BUT WILL NOT CHANGE CURRENT DRY FCST
UNTIL HAVE MORE CONFIDENCE.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
LIGHT WINDS AND MOIST LOW LVLS LEADING TO WDSPRD IFR CIGS EARLY THIS
MORNING WITH MAINLY MVFR VSBYS. FRONT WILL PUSH OFFSHORE EARLY THIS
MORNING BUT NO STRONG DRYING BEHIND IT AND MODEL RH XSCTNS INDICATE
CIGS LIFTING BUT NOT SCATTERING OUT UNTIL AFTN. ENOUGH DRYING
TONIGHT FOR VFR.
VFR CONTINUING SAT-SUN WITH HIGH PRES EXTENDING IN...THEN CONDITIONS
LOWERING SUN NIGHT-MON WITH LOW PRES MOVING ACROSS. CONDITIONS
IMPROVING AGAIN MON NIGHT-TUE WITH HIGH PRES AGAIN.
&&
.MARINE...
FRONT MOVING ACROSS WATERS EARLY THIS MORNING AND CAA SURGE TO
AROUND SCA SPEEDS EXPECTED BEHIND IT DURING THE DAY. NW-N WINDS WILL
INCREASE FIRST OVER SRN WATERS EARLY THIS MORNING BUT MAIN SURGE
WILL DEVELOPE MID-MORNING OVER NRN WATERS AND SPREAD S THROUGH EARLY
AFTN. KEPT SPEEDS AT 15-20 KTS ALL WATERS BUT MENTIONED GUSTS TO 25
KT OUTER WATERS. SEAS MAY DROP BELOW 6 FT BRIEFLY THIS MORNING FOR
NRN AND CENTRAL WATERS BUT WILL INCREASE QUICKLY WITH SURGE...THUS
KEPT SCA IN PLACE. DID DROP SCA EARLY FOR SRN WATERS BUT STARTED IT
AGAIN LATE AFTN.
MODERATE NE WINDS AND HIGHER SEAS WILL PERSIST TONIGHT INTO SAT. LOW
CONFIDENCE FCST WITH NEXT LOW PRES SYSTEM AFFECTING AREA LATE SUN
INTO MON AND DID NOT MAKE SIGNIFICANT CHANGE TO PREVIOUS
FCST...KEEPING LOW TRACK OFFSHORE. MODELS ARE TRENDING MORE TOWARD
MOVEMENT ALONG COAST BUT WILL LET DAY SHIFT TAKE A LOOK.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ029-
044>047-079>081-090>095-098.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST SATURDAY NIGHT FOR
AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR AMZ156.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ150.
SMALL CRAFT ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
AMZ158.
&&
$$
SYNOPSIS...RF
NEAR TERM...RF
SHORT TERM...RF
LONG TERM...RF
AVIATION...JBM
MARINE...JBM
000
FXUS62 KRAH 200825
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
325 AM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO CENTRAL NORTH CAROLINA TODAY AND
SETTLE OVERHEAD TONIGHT. THE HIGH WILL DRIFT EAST SATURDAY...IN
ADVANCE OF THE NEXT STORM SYSTEM EXPECTED TO EFFECT THE REGION
SUNDAY AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM FRIDAY...
OF IMMEDIATE CONCERN IN THIS FORECAST PERIOD IS THE POTENTIAL FOR
WIDESPREAD FOG AND ATTENDANT ADVISORY. VISIBILITIES BELOW HALF MILE
COMMON OVER THE SOUTHERN PIEDMONT AND SHOULD SEE VISIBILITIES DROP
IN THE TRIANGLE REGION AND SANDHILLS SHORTLY AS LOW STRATUS HAS
DIMINISHED. IN THE NW PIEDMONT...DRIER AIR HAS BEGUN TO FILTER TO
THE SURFACE AS DEWPOINTS HAVE DROPPED FROM THE LOWER 50S INTO THE
MID 40S AT KINT THE PAST COUPLE OF HOURS. EXPECT SIMILAR TREND OVER
THE REMAINDER OF THE NW PIEDMONT SO WILL LIKELY CANCEL ADVISORY FOR
THE TRIAD REGION WITH ZONE ISSUANCE. OVER THE COASTAL PLAIN...LOW
STRATUS MAY PERSIST LONG ENOUGH (THROUGH SUNRISE) TO PREVENT DENSE
FOG FROM DEVELOPING. FOR NOW WILL LET ADVISORY CONTINUE BUT MAY
CANCEL BY 6 OR 7 AM IF IT APPEARS THAT STRATUS WILL LINGER.
OTHERWISE HIGH PRESSURE WILL BUILD INTO THE FORECAST AREA TODAY.
EXPECT STEADY NLY BREEZE AFTER SUNRISE WITH INFREQUENT GUSTS THIS
MORNING BETWEEN 15-20KTS. ASIDE FROM A FEW-SCATTERED CLOUDS AROUND
2000FT...EXPECT A LOT OF SUN TODAY. THICKNESSES WITH FULL SUN
SUPPORT TEMPS IN THE LOW/MID 60S WITH UPPER 60S POSSIBLE SE. MOS
GUIDANCE SIMILAR AS WELL AS PREVIOUS FORECAST SO SEE LITTLE NEED TO
ADJUST.
TONIGHT...MODEL RH PROFILE CONTINUE TO DEPICT RETURN OF HIGH LEVEL
MOISTURE IN ADVANCE OF SOUTHERN STREAM S/W. STILL SOME UNCERTAINTY
AS TO OPAQUENESS OF HIGH CLOUDS THOUGH AND MOS GUIDANCE KEEP SKY
COVERAGE NO WORSE THAN FEW. THUS SHOULD SEE DECENT NOCTURNAL COOLING
CONDITIONS TONIGHT. IF TOP SOIL WAS NOT SO SATURATED...COULD SEE
TEMPS LOWER INTO THE LOW AND MID 30S. HOWEVER RESIDUAL LOW LEVEL
MOISTURE WILL MAINTAIN SOME WARMTH NEAR THE SURFACE SO EXPECT MIN
TEMPS UPPER 30S NEAR 40 NW TO MID 40S SE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
AS OF 315 AM FRIDAY...
MID/UPPER LEVEL MOISTURE INCREASES AND DEEPENS SATURDAY IN SW FLOW
OVERHEAD IN ADVANCE OF SOUTHERN STREAM SYSTEM IN THE NW GULF.
MEANWHILE PARENT SURFACE HIGH MIGRATES FROM THE LOWER OH VALLEY
TOWARD THE EASTERN LAKES WITH RIDGE EXTENDING INTO THE WESTERN
PIEDMONT. THIS WILL RESULT IN A N-NE LOW LEVEL FLOW...ADVECTING
COOL AND RELATIVELY DRY AIR. MAX TEMPS SATURDAY DEPENDENT UPON WHEN
MID/HIGH CLOUDS BECOME OPAQUE ENOUGH TO BLOCK OUT SUN. WILL MAINTAIN
MAX TEMPS AS PER PREVIOUS FORECAST (AROUND 60 NW TO MID 60S SE). IF
GFS CORRECT...SKIES BECOME OVERCAST BY MIDDAY. IF THIS OCCURS...MAX
TEMPS WILL LIKELY BE 3-4 DEGREES COOLER...ESPECIALLY IN THE
WEST.
SATURDAY NIGHT...925-850MB FLOW BACKS AND STRENGTHENS IN RESPONSE TO
APPROACH OF SOUTHERN STREAM LOW PRESSURE SYSTEM LIFTING ACROSS THE
LOWER MS VALLEY. EXPECT CLOUDS TO LOWER THICKEN. ISENTROPIC LIFT
INCREASES TOWARD 12Z IN THE 300-305 LAYER...MORE SO AFTER 12Z. WILL
MAINTAIN DRY CONDITIONS THROUGH 06Z..THEN MAINTAIN CONTINUE PREVIOUS
FORECAST OF INCREASING POPS SW-NE AFTER 06Z. REFRAINED FROM
INCREASING POPS ABOVE 40 PERCENT. RH PROFILES DEPICT RELATIVELY DRY
SUB CLOUD LAYER TILL 12Z SO INITIAL PRECIP WILL GO TOWARD MOISTENING
THIS LAYER. IF MOISTENING OCCURS FASTER THAN EXPECTED THEN COULD SEE
NEED TO INCREASE POPS TO LOW END LIKELY IN THE FAR W-SW. RAISED MIN
TEMPS A FEW DEGREES BASED ON THICKENING CLOUD COVERAGE IN THE WEST.
MIN TEMPS LOWER 40S NE TO MID/UPPER 40S WEST-SOUTH. -WSS
BY 12Z SUNDAY...A SOUTHERN STREAM SHORTWAVE TROUGH IS PROGGED TO
HAVE BECOME NEGATIVELY TILTED...LIFTING FROM THE GULF COAST INTO THE
TN VALLEY REGION. WITH A 1025MB HIGH OVER THE NY/CANADA
BORDER...AND A SURFACE LOW LIFTING NORTHEAST WITH THE
SHORTWAVE...MODELS HAVE BEEN SHOWING A MILLER B TYPE SURFACE
PRESSURE EVOLUTION FOR SUNDAY INTO SUNDAY NIGHT. AS THE SHORTWAVE
AND LOW LIFT NORTHEAST..AND A SOUTHERN STREAM JET IS PULLED
NORTHWARD...UPPER LEVEL DIFFLUENCE WILL INCREASE OVER CENTRAL
NC...AND COMBINED WITH STRENGTHENING 850MB FLOW AND LOW LEVEL WARM
ADVECTION...EXPECT RAIN CHANCES TO INCREASE RAPIDLY SUNDAY MORNING.
THERE ARE STILL SOME INCONSISTENCIES AMONG MODEL GUIDANCE ON THE
STRENGTH OF THE SHORTWAVE AS IT PASSES BY...AND ALSO ON THE TIMING
OF DEVELOPMENT AND MOVEMENT OF THE SECONDARY SURFACE LOW ALONG THE
COAST. THE SHORTWAVE IS EXPECTED TO BE SHEARING OUT AS IT LIFTS
THROUGH THE TN VALLEY REGION...AND THE NAM/GFS ARE STRONGER AND
FASTER THAN THE ECMWF OR CANADIAN...WHOSE LATEST RUNS HAVE COME IN
WITH A MORE MILLER TYPE A SURFACE LOW TRACK (POSSIBLY DUE TO A MORE
SOUTHWARD POSITION OF THE SURFACE HIGH TO OUR NORTH). QPF FORECAST
ALSO SUFFERS FROM THESE DIFFERENCES...BUT THERE SEEMS TO BE A
GENERAL TREND TOWARDS A SPLIT...WITH BEST COVERAGE INITIALLY WITH
THE UPPER WAVE AND ISENTROPIC LIFT IN THE WEST...SHIFTING TO THE
EAST AS THE SECONDARY LOW DEVELOPS OFF THE SAVANNAH COAST SUNDAY
NIGHT AND TRACKS NORTH SOMEWHERE ALONG THE COAST. FOR NOW...WILL
NOT MAKE MANY CHANGES TO THE CURRENT FORECAST...WITH POPS INCREASING
TO LIKELY AFTER 12Z SUNDAY...WITH THE HIGHEST POPS SHIFTING TO THE
EAST AFTER 00Z MONDAY. AS MENTIONED IN EARLIER DISCUSSIONS...THE
CURRENT FORECAST TRACK OF THE COASTAL LOW KEEPS THE CWA ON THE COOL
SIDE OF THE COASTAL FRONT AND THUS VOID OF ANY SURFACE BASED
CONVECTION. HIGHS SUNDAY WILL VARY WIDELY FROM THE COOL CAD AIRMASS
IN THE WEST WHERE MID TO UPPER 40S ARE POSSIBLE...TO WARMER UPPER
50S TO EVEN 60 IN THE SE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 305 AM FRIDAY...
MID LEVEL DRY AIR WILL BRING RAIN TO AN END FROM SW TO NE ON MONDAY
AS A SURFACE HIGH BUILDS ACROSS THE SE US AND WILL HAVE ALL POPS OUT
OF THE CWA BY 00Z TUESDAY. FORECAST LOW LEVEL THICKNESSES CLIMB
20-30M ON MONDAY WITH A WELL MODIFIED HIGH TAKING HOLD. A SLOWER
TRACK OF A COASTAL LOW COULD KEEP CLOUD COVER IN LONGER....A
REINFORCED NORTHERLY FLOW OVER THE AREA... AND HIGHS COOLER. PREFER
A BLEND OF GUIDANCE...59-66 NW-SE.
SURFACE HIGH PRESSURE RIDGE SETTLES OVER THE AREA TUESDAY MORNING
WHICH COULD LEAD TO FOG ISSUES DEPENDING ON ANTECEDENT RAINFALL.
OTHERWISE...TUES LOOKS TO BE A NICE DAY WITH THE NEXT WEATHER SYSTEM
REMAINING WEST OF THE MOUNTAINS. MORNING LOWS COOL IN THE LOW TO
MID 40S. HIGHS IN THE LOW TO MID 60S...JUST ABOVE NORMAL.
MODELS HAVE YET TO SHOW SIGNS OF CONVERGING ON A SOLUTION FOR A
POTENTIAL UPPER LOW OVER THE UPPER MIDWEST BY WEDNESDAY...WITH ITS
COLD FRONT CROSSING THE MOUNTAINS BY WED NIGHT. THE FRONT WOULD BE
WELL SEPARATED FROM ITS PARENT LOW...AND LIKELY VOID OF MUCH
PRECIP. BEHIND THE FRONT...GUIDANCE IS SLOW TO SHOW MUCH AIRMASS
CHANGE...UNTIL A SECOND POTENTIAL CLIPPER SHORTWAVE DIVES SOUTHEAST
THROUGH THE MIDWEST AND INTO THE MID ATLANTIC ON THURS...BRINGING A
SURGE OF COLDER AND DRIER AIR BEHIND IT. CURRENT FORECAST WILL
REMAIN DRY WITH TEMPS FALLING TO BELOW NORMAL BY THEN END OF THE
PERIOD.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1230 AM FRIDAY...
WIDESPREAD LIFR VISIBILITIES EXPECTED THROUGH 12Z OVER MOST OF
CENTRAL NC AS DRIER AIR ALOFT AS CLEARED OUT CLOUDS. RESIDUAL NEAR
SURFACE MOISTURE HAS ALLOWED FOG AND LOW STRATUS TO DEVELOP. EXPECT
VISIBILITIES AT OR BELOW A MILE WITH VISIBILITIES BELOW A HALF MILE
QUITE COMMON. AS DRIER AIR GRADUALLY MIXES TOWARD THE SURFACE AFTER
09Z...EXPECT VISIBILITIES TO IMPROVE FROM WEST TO EAST.
AFTER 13Z...DRIER AIR THROUGHOUT THE ENTIRE ATMOSPHERE SHOULD RESULT
IN CLEAR OR MOSTLY CLEAR SKIES. NEAR SURFACE WINDS WILL BE NORTHERLY
AROUND 10 KTS WITH INFREQUENT GUSTS 16-19KTS THROUGH 18Z. AS HIGH
PRESSURE BUILDS FARTHER INTO THE REGION...WINDS WILL GRADUALLY
SUBSIDE.
VFR CONDITIONS WILL PERSIST FRIDAY NIGHT INTO SATURDAY WITH ONLY
PATCHES OF HIGH CLOUDS EXPECTED AND WINDS RELATIVELY LIGHT AND
VARIABLE.
A STORM SYSTEM WILL APPROACH FROM THE SW SATURDAY NIGHT AND AFFECT
THE REGION SUNDAY THROUGH MONDAY MORNING...BRINGING MVFR OR IFR
CONDITIONS.
VFR CONDITIONS RETURN TO THE AREA LATE MONDAY AND PERSIST INTO
TUESDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM EST FRIDAY FOR NCZ007>011-
023>028-040>043-075>078-085-086-088-089.
DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
NCZ073-074-083-084.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...WSS/SMITH
LONG TERM...SMITH
AVIATION...WSS
000
FXUS62 KILM 200812
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
312 AM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL RIDGE INTO THE AREA FROM THE NORTH THROUGH
SATURDAY. LOW PRESSURE EMERGING FROM THE GULF OF MEXICO WILL
BRING WIDESPREAD RAINS TO THE EASTERN CAROLINAS SUNDAY AND SUNDAY
NIGHT...THEN PULL AWAY TO THE NORTHEAST MONDAY. DRY AND MILD
HIGH PRESSURE WILL BUILD IN FOR MUCH OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM FRIDAY...VAPOR IMAGERY FROM SPACE THIS MORNING SHOWS
A BROAD BUT FILLING UPPER LOW PICKING UP FORWARD SPEED ACROSS THE
GREAT LAKES...BUT LOOSENING IT INFLUENCE ON THE COLUMN WINDS
ACROSS OUR FORECAST AREA. IR CHANNEL SHOWS DEEP CONVECTION
ERUPTING ALONG THE TEXAS COAST UPSTREAM WHERE CYCLOGENESIS WAS
GEARING UP. 11U-3.9U CHANNEL SHOWS EXTENSIVE FOG OVER OUR REGION
AS CLEARING HAS TEAMED WITH A VERY DAMP BOUNDARY LAYER AND MOIST
SOILS. 1/4SM VSBYS NOT WIDESPREAD BUT WILL NOT DROP ACTIVE DFA
UNTIL AN 8Z-10Z TREND IS OBSERVED PRIOR TO 600 AM ISSUANCES.
A COLD FRONT HAS MOVED OFFSHORE AND ORIENTED NORTH TO SOUTH STILL
CLIPPED PORTIONS OF THE OUTER BANKS WHERE SATELLITE ESTIMATED
PLUMES OF HIGHER PRECIPITABLE WATERS LURKED JUST OFFSHORE. OUR
PRECIPITATION CHANCES HAVE ENDED OVER LAND. VAD WIND PROFILE SHOWS
A 3000 FOOT DEEP LAYER ON POST-FRONTAL NORTHERLY WIND FLOW. THIS
FLOW SHOULD DEEPEN A BIT MORE ACCOMPANIED BY MODERATE WIND SPEEDS.
THIS SHOULD BE ADEQUATE TO ERODE A GOOD PORTION OF THE STRATUS/FOG
LAYER BY LATE MORNING...WITH SOME AFTERNOON CUMULUS. WITH ONLY
WEAK COLD AIR ADVECTION BEHIND THIS FRONT...AND AFTERNOON BEAMS
OF DEL SOL...THINK MANY SPOTS WILL FLIRT WITH 70 DEGREE MARK.
QUIET OVERNIGHT IN MODERATE BUT SHALLOW NE WIND FLOW AND VERY DRY
AIR ABOVE 4000 FEET. IF WINDS COULD DECOUPLE ENOUGH TONIGHT...FOG
MAY RETURN BUT NOT AS DENSE OR WIDESPREAD AS WE SEE CURRENTLY.
MAINLY CLEAR SKIES TONIGHT SHOULD ALLOW LOWS BY DAYBREAK TO DIP
INTO THE 40S TO KICK-OFF SATURDAY.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...WILL CONTINUE THE TREND OF SLOWING DOWN A
COMPLEX STORM SYSTEM THAT WILL LIFT OUT OF THE GULF THIS WEEKEND.
IT NOW APPEARS THAT THE CWA WILL REMAIN DRY FOR ALL OF SATURDAY
AND INTO SATURDAY EVENING. MAX TEMPS NEAR NORMAL FOR THIS TIME OF
YEAR...LIMITED MAINLY BY INCREASING HIGH CLOUDS AHEAD OF THE LOW
DEVELOPING ALONG THE GULF COAST.
LATEST NAM AND GFS ARE NOW DEPICTING MILLER TYPE-B CYCLOGENESIS AS
WE HEAD INTO SUNDAY...BUT AT THIS POINT THINK THE MAIN POINT IS
THAT IT WILL HAPPEN MORE SLOWLY. ENOUGH DRY AIR FROM 850-750MB
THAT IT WILL TAKE MOST OF SATURDAY NIGHT TO OVERCOME...SO HAVE
TAPERED POPS FROM HIGH CHANCE IN THE SOUTH TO LOW CHANCE IN THE
NORTH. WENT WITH LIKELY SUNDAY INTO SUNDAY NIGHT AS THE MOISTURE
FEED BECOMES WELL ESTABLISHED AROUND 12Z SUN...AND PERSISTS BEYOND
00Z MON. THERE IS CERTAINLY AN ARGUMENT TO BE MADE FOR A RAPID
SHUTOFF IN THE PRECIP SUN NIGHT...BUT NOT GETTING TOO CUTE WITH
THE TIMING THIS FAR OUT.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...DRY WEATHER PATTERN IN STORE FOR THE
EXTENDED...WITH CHILLY AIR KNOCKING ON THE DOOR BY THE END. SFC
RIDGING ALONG THE GULF COAST AND A FLAT UPPER PATTERN WILL KEEP
TEMPS MILD...WITH HIGHS CLOSE TO 70 MON-WED AND LOWS ALSO A
CATEGORY OR TWO ABOVE CLIMO. BY THURSDAY LOOK FOR A FULL-LATITUDE
TROUGH TO SETTLE IN ALONG THE EAST COAST. HARD TO TIME THE
ASSOCIATED COLD FRONT...BUT REGARDLESS IT LOOKS TO BE MOISTURE-
STARVED...SO NO POPS WILL BE INCLUDED AT THIS TIME. DAYTIME TEMPS
NEAR NORMAL FOR TURKEY DAY...AS THE CHILLY AIR HOLDS OFF UNTIL
BEYOND THE VALID PERIOD OF THE ZONE FORECAST.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
LOOKS LIKE FOG/STRATUS WILL SET UP OVER MOST OF THE REGION
TONIGHT...WITH POTENTIALLY LOW VISIBILITIES. ATMOSPHERE SHOULD MIX
OUT FAIRLY QUICKLY TOMORROW WITH VFR EXPECTED AT ALL TERMINALS BY
MID MORNING. HIGH PRESSURE WILL CONTINUE TO BUILD IN ALL DAY WITH A
NORTH NORTHEAST WIND...A BIT GUSTY IN THE AFTERNOON.
EXTENDED OUTLOOK...VFR FRIDAY/SATURDAY. SHOWERS AND LOW CEILINGS
MOVE BACK IN SATURDAY NIGHT THROUGH MONDAY MORNING.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM FRIDAY...NORTHERLY WIND FLOW OVER THE WATERS AS A COLD
FRONT PUSHES FARTHER TO SEA. WAVE ENERGY WAS SPREAD OUT NEARLY
EQUALLY BETWEEN WAVE PERIODS 4-9 SECONDS...WITH NORTHERLY WIND-
WAVES AND UNDERLYING ESE SWELL ENERGY PROPAGATING TOWARD
SHORE...SO PRETTY DOGGONE BUMPY. PERSISTENT FETCH BEYOND THE COLD
FRONT WILL MAINTAIN ONSHORE WAVE ENERGY INTO THE CAROLINA SHORES
IN THE 7-9 SECOND PERIOD RANGE FOR THE NEXT FEW DAYS. THIS COUPLED
WITH NE SURFACE WINDS WILL SUSTAIN BUMPY BOATING CONDITIONS INTO
THE WEEKEND.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...EXPECT STATUS QUO WITH NE WINDS SATURDAY AND
SATURDAY NIGHT. FOR NOW WILL KEEP SPEEDS AROUND 15 KT...BUT THE
GRADIENT APPEARS TO TIGHTEN BY SUNDAY MORNING. COULD SEE A SOLID
20 KT...AND THE NE FETCH WILL BE PERSISTENT ENOUGH TO GENERATE
SOME 6 FT SEAS ALONG FRYING PAN SHOALS AND OFF CAPE ROMAIN. NOT
NEARLY AS MUCH FETCH TO WORK WITH NEAR SHORE...SO LOOK FOR A MUCH
MORE MODEST 2-3 FT THERE.
SUNDAY NIGHT IS THE LOW CONFIDENCE PORTION OF THE FORECAST. LATEST
NAM AND GFS NOW TRY TO PULL THE LOW IN OVER LAND AS IT CROSSES
EASTERN NC. NOT SOLD ENOUGH ON THIS SOLUTION JUST YET...SO WILL
REMAIN CLOSE TO THE PREVIOUS FORECAST WHICH MAINTAINS AN OFFSHORE
TRACK. WILL BRING THE LOW CLOSE ENOUGH TO SEE A VEERING TO ENE
AHEAD OF IT...AND BACKING TO NW AS THE LOW DEPARTS. LOOK FOR A
DIMINISHING TREND IN WINDS DUE TO PROXIMITY OF THE LOW...AND SEAS
GENERALLY IN THE 3-4 FT RANGE FOR MUCH OF THE NIGHT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...WILL START OFF MONDAY WITH NW WINDS BEHIND
DEPARTING LOW PRESSURE. WITH THE HIGH BUILDING FROM THE GULF COAST
AND FLAT RIDGING ALOFT...WOULD NOT EXPECT ANY COLD AIR SURGE...SO
WIND SPEEDS WILL REMAIN QUITE TAME...AROUND 10 KT. COULD SEE WINDS
BACK AROUND TO WESTERLY ON TUESDAY AS THE SFC RIDGE IS SUPPRESSED
A LITTLE FARTHER SOUTH...AND A NORTHERN STREAM IMPULSE SCOOTS
QUICKLY INTO THE MID-ATLANTIC STATES. SEAS 2-4 FT TO BEGIN
WITH...BUT SUBSIDING TO AROUND 2 FT THROUGHOUT IN THE LIGHT
OFFSHORE FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ017-023-
024-032>034-039-046.
NC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ087-096-
097-099>101.
MARINE...NONE.
&&
$$
NEAR TERM...MJC
SHORT TERM...RAS
LONG TERM...RAS
AVIATION...MJC/DL
000
FXUS62 KRAH 200809
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
305 AM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO CENTRAL NORTH CAROLINA TODAY AND
SETTLE OVERHEAD TONIGHT. THE HIGH WILL DRIFT EAST SATURDAY...IN
ADVANCE OF THE NEXT STORM SYSTEM EXPECTED TO EFFECT THE REGION
SUNDAY AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM FRIDAY...
OF IMMEDIATE CONCERN IN THIS FORECAST PERIOD IS THE POTENTIAL FOR
WIDESPREAD FOG AND ATTENDANT ADVISORY. VISIBILITIES BELOW HALF MILE
COMMON OVER THE SOUTHERN PIEDMONT AND SHOULD SEE VISIBILITIES DROP
IN THE TRIANGLE REGION AND SANDHILLS SHORTLY AS LOW STRATUS HAS
DIMINISHED. IN THE NW PIEDMONT...DRIER AIR HAS BEGUN TO FILTER TO
THE SURFACE AS DEWPOINTS HAVE DROPPED FROM THE LOWER 50S INTO THE
MID 40S AT KINT THE PAST COUPLE OF HOURS. EXPECT SIMILAR TREND OVER
THE REMAINDER OF THE NW PIEDMONT SO WILL LIKELY CANCEL ADVISORY FOR
THE TRIAD REGION WITH ZONE ISSUANCE. OVER THE COASTAL PLAIN...LOW
STRATUS MAY PERSIST LONG ENOUGH (THROUGH SUNRISE) TO PREVENT DENSE
FOG FROM DEVELOPING. FOR NOW WILL LET ADVISORY CONTINUE BUT MAY
CANCEL BY 6 OR 7 AM IF IT APPEARS THAT STRATUS WILL LINGER.
OTHERWISE HIGH PRESSURE WILL BUILD INTO THE FORECAST AREA TODAY.
EXPECT STEADY NLY BREEZE AFTER SUNRISE WITH INFREQUENT GUSTS THIS
MORNING BETWEEN 15-20KTS. ASIDE FROM A FEW-SCATTERED CLOUDS AROUND
2000FT...EXPECT A LOT OF SUN TODAY. THICKNESSES WITH FULL SUN
SUPPORT TEMPS IN THE LOW/MID 60S WITH UPPER 60S POSSIBLE SE. MOS
GUIDANCE SIMILAR AS WELL AS PREVIOUS FORECAST SO SEE LITTLE NEED TO
ADJUST.
TONIGHT...MODEL RH PROFILE CONTINUE TO DEPICT RETURN OF HIGH LEVEL
MOISTURE IN ADVANCE OF SOUTHERN STREAM S/W. STILL SOME UNCERTAINTY
AS TO OPAQUENESS OF HIGH CLOUDS THOUGH AND MOS GUIDANCE KEEP SKY
COVERAGE NO WORSE THAN FEW. THUS SHOULD SEE DECENT NOCTURNAL COOLING
CONDITIONS TONIGHT. IF TOP SOIL WAS NOT SO SATURATED...COULD SEE
TEMPS LOWER INTO THE LOW AND MID 30S. HOWEVER RESIDUAL LOW LEVEL
MOISTURE WILL MAINTAIN SOME WARMTH NEAR THE SURFACE SO EXPECT MIN
TEMPS UPPER 30S NEAR 40 NW TO MID 40S SE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 305 AM FRIDAY...
DISCUSSION FOR SATURDAY TO COME SHORTLY...
BY 12Z SUNDAY...A SOUTHERN STREAM SHORTWAVE TROUGH IS PROGGED TO
HAVE BECOME NEGATIVELY TILTED...LIFTING FROM THE GULF COAST INTO THE
TN VALLEY REGION. WITH A 1025MB HIGH OVER THE NY/CANADA
BORDER...AND A SURFACE LOW LIFTING NORTHEAST WITH THE
SHORTWAVE...MODELS HAVE BEEN SHOWING A MILLER B TYPE SURFACE
PRESSURE EVOLUTION FOR SUNDAY INTO SUNDAY NIGHT. AS THE SHORTWAVE
AND LOW LIFT NORTHEAST..AND A SOUTHERN STREAM JET IS PULLED
NORTHWARD...UPPER LEVEL DIFFLUENCE WILL INCREASE OVER CENTRAL
NC...AND COMBINED WITH STRENGTHENING 850MB FLOW AND LOW LEVEL WARM
ADVECTION...EXPECT RAIN CHANCES TO INCREASE RAPIDLY SUNDAY MORNING.
THERE ARE STILL SOME INCONSISTENCIES AMONG MODEL GUIDANCE ON THE
STRENGTH OF THE SHORTWAVE AS IT PASSES BY...AND ALSO ON THE TIMING
OF DEVELOPMENT AND MOVEMENT OF THE SECONDARY SURFACE LOW ALONG THE
COAST. THE SHORTWAVE IS EXPECTED TO BE SHEARING OUT AS IT LIFTS
THROUGH THE TN VALLEY REGION...AND THE NAM/GFS ARE STRONGER AND
FASTER THAN THE ECMWF OR CANADIAN...WHOSE LATEST RUNS HAVE COME IN
WITH A MORE MILLER TYPE A SURFACE LOW TRACK (POSSIBLY DUE TO A MORE
SOUTHWARD POSITION OF THE SURFACE HIGH TO OUR NORTH). QPF FORECAST
ALSO SUFFERS FROM THESE DIFFERENCES...BUT THERE SEEMS TO BE A
GENERAL TREND TOWARDS A SPLIT...WITH BEST COVERAGE INITIALLY WITH
THE UPPER WAVE AND ISENTROPIC LIFT IN THE WEST...SHIFTING TO THE
EAST AS THE SECONDARY LOW DEVELOPS OFF THE SAVANNAH COAST SUNDAY
NIGHT AND TRACKS NORTH SOMEWHERE ALONG THE COAST. FOR NOW...WILL
NOT MAKE MANY CHANGES TO THE CURRENT FORECAST...WITH POPS INCREASING
TO LIKELY AFTER 12Z SUNDAY...WITH THE HIGHEST POPS SHIFTING TO THE
EAST AFTER 00Z MONDAY. AS MENTIONED IN EARLIER DISCUSSIONS...THE
CURRENT FORECAST TRACK OF THE COASTAL LOW KEEPS THE CWA ON THE COOL
SIDE OF THE COASTAL FRONT AND THUS VOID OF ANY SURFACE BASED
CONVECTION. HIGHS SUNDAY WILL VARY WIDELY FROM THE COOL CAD AIRMASS
IN THE WEST WHERE MID TO UPPER 40S ARE POSSIBLE...TO WARMER UPPER
50S TO EVEN 60 IN THE SE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 305 AM FRIDAY...
MID LEVEL DRY AIR WILL BRING RAIN TO AN END FROM SW TO NE ON MONDAY
AS A SURFACE HIGH BUILDS ACROSS THE SE US AND WILL HAVE ALL POPS OUT
OF THE CWA BY 00Z TUESDAY. FORECAST LOW LEVEL THICKNESSES CLIMB
20-30M ON MONDAY WITH A WELL MODIFIED HIGH TAKING HOLD. A SLOWER
TRACK OF A COASTAL LOW COULD KEEP CLOUD COVER IN LONGER....A
REINFORCED NORTHERLY FLOW OVER THE AREA... AND HIGHS COOLER. PREFER
A
BLEND OF GUIDANCE...59-66 NW-SE.
SURFACE HIGH PRESSURE RIDGE SETTLES OVER THE AREA TUESDAY MORNING
WHICH COULD LEAD TO FOG ISSUES DEPENDING ON ANTECEDENT RAINFALL.
OTHERWISE...TUES LOOKS TO BE A NICE DAY WITH THE NEXT WEATHER SYSTEM
REMAINING WEST OF THE MOUNTAINS. MORNING LOWS COOL IN THE LOW TO
MID 40S. HIGHS IN THE LOW TO MID 60S...JUST ABOVE NORMAL.
MODELS HAVE YET TO SHOW SIGNS OF CONVERGING ON A SOLUTION FOR A
POTENTIAL UPPER LOW OVER THE UPPER MIDWEST BY WEDNESDAY...WITH ITS
COLD FRONT CROSSING THE MOUNTAINS BY WED NIGHT. THE FRONT WOULD BE
WELL SEPARATED FROM ITS PARENT LOW...AND LIKELY VOID OF MUCH
PRECIP. BEHIND THE FRONT...GUIDANCE IS SLOW TO SHOW MUCH AIRMASS
CHANGE...UNTIL A SECOND POTENTIAL CLIPPER SHORTWAVE DIVES SOUTHEAST
THROUGH THE MIDWEST AND INTO THE MID ATLANTIC ON THURS...BRINGING A
SURGE OF COLDER AND DRIER AIR BEHIND IT. CURRENT FORECAST WILL
REMAIN DRY WITH TEMPS FALLING TO BELOW NORMAL BY THEN END OF THE
PERIOD.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1230 AM FRIDAY...
WIDESPREAD LIFR VISIBILITIES EXPECTED THROUGH 12Z OVER MOST OF
CENTRAL NC AS DRIER AIR ALOFT AS CLEARED OUT CLOUDS. RESIDUAL NEAR
SURFACE MOISTURE HAS ALLOWED FOG AND LOW STRATUS TO DEVELOP. EXPECT
VISIBILITIES AT OR BELOW A MILE WITH VISIBILITIES BELOW A HALF MILE
QUITE COMMON. AS DRIER AIR GRADUALLY MIXES TOWARD THE SURFACE AFTER
09Z...EXPECT VISIBILITIES TO IMPROVE FROM WEST TO EAST.
AFTER 13Z...DRIER AIR THROUGHOUT THE ENTIRE ATMOSPHERE SHOULD RESULT
IN CLEAR OR MOSTLY CLEAR SKIES. NEAR SURFACE WINDS WILL BE NORTHERLY
AROUND 10 KTS WITH INFREQUENT GUSTS 16-19KTS THROUGH 18Z. AS HIGH
PRESSURE BUILDS FARTHER INTO THE REGION...WINDS WILL GRADUALLY
SUBSIDE.
VFR CONDITIONS WILL PERSIST FRIDAY NIGHT INTO SATURDAY WITH ONLY
PATCHES OF HIGH CLOUDS EXPECTED AND WINDS RELATIVELY LIGHT AND
VARIABLE.
A STORM SYSTEM WILL APPROACH FROM THE SW SATURDAY NIGHT AND AFFECT
THE REGION SUNDAY THROUGH MONDAY MORNING...BRINGING MVFR OR IFR
CONDITIONS.
VFR CONDITIONS RETURN TO THE AREA LATE MONDAY AND PERSIST INTO
TUESDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM EST FRIDAY FOR NCZ007>011-
023>028-040>043-075>078-085-086-088-089.
DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
NCZ073-074-083-084.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...WSS
000
FXUS62 KRAH 200801
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
300 AM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO CENTRAL NORTH CAROLINA TODAY AND
SETTLE OVERHEAD TONIGHT. THE HIGH WILL DRIFT EAST SATURDAY...IN
ADVANCE OF THE NEXT STORM SYSTEM EXPECTED TO EFFECT THE REGION
SUNDAY AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 245 AM FRIDAY...
OF IMMEDIATE CONCERN IN THIS FORECAST PERIOD IS THE POTENTIAL FOR
WIDESPREAD FOG AND ATTENDANT ADVISORY. VISIBILITIES BELOW HALF MILE
COMMON OVER THE SOUTHERN PIEDMONT AND SHOULD SEE VISIBILITIES DROP
IN THE TRIANGLE REGION AND SANDHILLS SHORTLY AS LOW STRATUS HAS
DIMINISHED. IN THE NW PIEDMONT...DRIER AIR HAS BEGUN TO FILTER TO
THE SURFACE AS DEWPOINTS HAVE DROPPED FROM THE LOWER 50S INTO THE
MID 40S AT KINT THE PAST COUPLE OF HOURS. EXPECT SIMILAR TREND OVER
THE REMAINDER OF THE NW PIEDMONT SO WILL LIKELY CANCEL ADVISORY FOR
THE TRIAD REGION WITH ZONE ISSUANCE. OVER THE COASTAL PLAIN...LOW
STRATUS MAY PERSIST LONG ENOUGH (THROUGH SUNRISE) TO PREVENT DENSE
FOG FROM DEVELOPING. FOR NOW WILL LET ADVISORY CONTINUE BUT MAY
CANCEL BY 6 OR 7 AM IF IT APPEARS THAT STRATUS WILL LINGER.
OTHERWISE HIGH PRESSURE WILL BUILD INTO THE FORECAST AREA TODAY.
EXPECT STEADY NLY BREEZE AFTER SUNRISE WITH INFREQUENT GUSTS THIS
MORNING BETWEEN 15-20KTS. ASIDE FROM A FEW-SCATTERED CLOUDS AROUND
2000FT...EXPECT A LOT OF SUN TODAY. THICKNESSES WITH FULL SUN
SUPPORT TEMPS IN THE LOW/MID 60S WITH UPPER 60S POSSIBLE SE. MOS
GUIDANCE SIMILAR AS WELL AS PREVIOUS FORECAST SO SEE LITTLE NEED TO
ADJUST.
TONIGHT...MODEL RH PROFILE CONTINUE TO DEPICT RETURN OF HIGH LEVEL
MOISTURE IN ADVANCE OF SOUTHERN STREAM S/W. STILL SOME UNCERTAINTY
AS TO OPAQUENESS OF HIGH CLOUDS THOUGH AND MOS GUIDANCE KEEP SKY
COVERAGE NO WORSE THAN FEW. THUS SHOULD SEE DECENT NOCTURNAL COOLING
CONDITIONS TONIGHT. IF TOP SOIL WAS NOT SO SATURATED...COULD SEE
TEMPS LOWER INTO THE LOW AND MID 30S. HOWEVER RESIDUAL LOW LEVEL
MOISTURE WILL MAINTAIN SOME WARMTH NEAR THE SURFACE SO EXPECT MIN
TEMPS UPPER 30S NEAR 40 NW TO MID 40S SE.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 250 PM THURSDAY...
FOR FRIDAY THROUGH SATURDAY: THE COLD FRONT SHOULD BE SHIFTING OFF
THE COAST BY FRIDAY MORNING. WITH RATHER LIGHT SURFACE WINDS BEHIND
THE FRONT AND PLENTY OF RESIDUAL NEAR-SURFACE MOISTURE... EXPECT
PATCHES OF FOG TO PERSIST PAST DAYBREAK. OTHERWISE... EXPECT A BRIEF
PERIOD OF QUIET WEATHER HEADING INTO SATURDAY. THE SURFACE HIGH
DRIFTS NORTH-NORTHEAST THROUGH THE OH VALLEY FRIDAY AS IT BEGINS TO
BUILD INTO NC. WITH A MAINLY FLAT SOUTHWEST MID LEVEL FLOW OVER THE
INTERIOR SOUTHEAST... FORECAST SOUNDINGS SHOW STABLE SUBSIDING AIR
ALOFT AND A DRY COLUMN. MODEL FORECAST LOW LEVEL THICKNESSES ARE
JUST SLIGHTLY ABOVE NORMAL... AND FACTORING IN PLENTY OF SUNSHINE
ALONG WITH UPSTREAM TEMPS AND THE MILD NATURE OF THE INCOMING AIR
MASS... EXPECT HIGHS OF 62-68. THE HIGH CENTER MOVES OVER WV FRIDAY
NIGHT AND CONTINUES RIDGING INTO NC... CAUSING SURFACE WINDS TO VEER
AROUND TO NORTH-NORTHEAST AND PULL IN COOLER AIR. FORECAST SOUNDINGS
SHOW SOME INCREASE IN HIGH CLOUDS OVERNIGHT AHEAD OF THE NEXT STORM
SYSTEM PUSHING INTO THE SOUTHERN PLAINS/WEST GULF REGION... HOWEVER
THESE APPEAR TO BE THIN ENOUGH TO HAVE MINIMAL IMPACT ON GROUND HEAT
LOSS. NUDGED LOWS DOWN A DEGREE OR SO TO 37-44. MID-UPPER LEVEL
MOISTURE STEADILY INCREASES AND DEEPENS SATURDAY AS THE MID LEVEL
VORTEX CROSSES LA INTO MS. THE SURFACE HIGH TO OUR NORTH PASSES
SLOWLY NORTHWARD TO THE OH/PA BORDER AND BECOMES SUPPORTED BY
CONFLUENT FLOW ALOFT WITH NORTHERN STREAM SHORTWAVE TROUGHING OVER
PA... AND THIS SHOULD ENSURE A STEADY FEED OF LOW LEVEL DRY AIR INTO
CENTRAL NC... SETTING US UP FOR DAMMING ONCE THE SURFACE HIGH CAN
GET INTO A MORE FAVORABLE POSITION (OVER THE ST LAWRENCE VALLEY)
SATURDAY NIGHT WHERE IT CAN TAP INTO EVEN COOLER AIR AND STRENGTHEN
FURTHER AND SUPPORT ALOFT PERSISTS. HIGHS SATURDAY 60-65 WITH
INCREASING AND THICKENING CLOUDS.
FOR SATURDAY NIGHT/SUNDAY: MODELS AGREE FAIRLY WELL ON THE MID LEVEL
SHORTWAVE TROUGH DEAMPLIFYING A BIT AS IT LIFTS WITH A NEGATIVE TILT
FROM NORTHEAST LA TO NORTHEAST MS SATURDAY NIGHT... WITH A STEADY
LOWERING OF THE CLOUD BASE OVER NC OVERNIGHT. ISENTROPIC UPGLIDE
COMMENCES OVER SOUTHERN NC LATE... HOWEVER THE LATEST MODEL GUIDANCE
SUGGESTS THAT MOST PRECIP WILL HOLD OFF UNTIL AT LEAST SUNDAY
MORNING. TYPICALLY... WITH ANOMALOUSLY LOW PRESSURE AREAS NEAR THE
GULF COAST REGION SUCH AS THIS... WE SEE SUBSTANTIAL CONVECTION IN
THE WARM SECTOR... FROM THE NORTHEAST GULF NORTHWARD INTO THE
EASTERN GULF STATES/GA... SOUTH OF THE WEDGE WARM FRONT WHICH IS
LIKELY TO EXTEND ACROSS CENTRAL GA AND SOUTHERN SC HEADING INTO
SUNDAY MORNING. GIVEN THAT THE BEST MOISTURE TRANSPORT WILL OCCUR
FROM THE NORTHEAST GULF UP AND OVER THIS WARM FRONT WHERE LOW LEVEL
MASS CONVERGENCE IS MAXIMIZED... AND CONSIDERING THE DRY SUBCLOUD
LAYER NOTED ON FORECAST SOUNDINGS... WE ARE LIKELY TO SEE ONLY VERY
LIGHT RAIN (IF ANYTHING) SATURDAY NIGHT. HAVE TRIMMED BACK POPS TO
LOW CHANCE AND CUT AMOUNTS DOWN TO JUST A FEW HUNDREDTHS THROUGH
DAYBREAK. LOWS 42-47. AS THE MID LEVEL LOW TRACKS UP THROUGH TN INTO
KY SUNDAY (A FARTHER-WEST TRACK THAN WHAT WAS SEEN ON YESTERDAY`S
MODELS)... EXPECT A MILLER TYPE B PATTERN TO DEVELOP WITH THE
PRIMARY LOW WELL WEST OF THE SOUTHERN APPALACHIANS AND SECONDARY LOW
PRESSURE DEVELOPING OFF THE CAROLINA COAST. ALONG WITH THE QUICKLY
SATURATING COLUMN (PRECIP WATER RISING TO 250% OF NORMAL)... FORCING
FOR ASCENT IMPROVES WITH DEEPENING AND STRENGTHENING ISENTROPIC
UPGLIDE... MID LEVEL HEIGHT FALLS... AND INCREASED OVERRUNNING WITH
30-35 KTS OF SOUTHERLY FLOW ATOP THE COOL DOME ASSOCIATED WITH THE
APPROACH FROM THE SOUTH OF THE 850 MB WARM FRONT. WILL HOLD ONTO
LIKELY POPS FOR SUNDAY. HOWEVER... WHILE THE DEEP SATURATION AND
FORCING MAKE LIGHT RAIN LIKELY... AMOUNTS ARE PROBLEMATIC TO
DETERMINE. UPPER DIVERGENCE IN THE LEFT EXIT REGION OF THE
SUBTROPICAL JET IS DECENT... BUT THE GREATEST DPVA HOLDS TO OUR
WEST. THE LATEST NAM SHOWS DRIER AIR ABOVE 0C AS COMPARED TO THE
GFS... AND IT FOCUSES MOST OF THE PRECIP AWAY FROM THE WEDGE... WELL
TO OUR WEST OVER THE MOUNTAINS AND OVER THE GULF STREAM. THE SREF
MEAN IS ALSO HINTING AT LESSER AMOUNTS WITH FAIRLY LOW PROBABILITY
OF MORE THAN 0.05" OF RAIN THROUGH EARLY SUNDAY EVENING... HOWEVER
THE GEFS MEAN HAS TRENDED WETTER. WILL KEEP TOTAL AMOUNTS AROUND A
QUARTER TO THIRD INCH FOR NOW. WITH CHILLY NORTHEAST WINDS AND NO
MECHANISMS TO DISLODGE THE COOL STABLE SURFACE BASED LAYER...
PIEDMONT TEMPS MAY STRUGGLE TO RISE... AND HAVE HELD CLOSE TO THE
EARLIER FORECAST... WITH HIGHS 48 TO 57. -GIH
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 255 PM THURSDAY...
FOR SUNDAY NIGHT: THE PRIMARY SURFACE LOW TO OUR WEST IS EXPECTED TO
HEAD INTO THE OHIO VALLEY AND WEAKEN WHILE THE SECONDARY LOW TREKS
UP INTO EASTERN NC. WE DRY OUT ABOVE THE FREEZING LEVEL AS THE MID
LEVEL DRY SLOT NOSES IN FROM THE SOUTHWEST... LEAVING A BRISK
NORTHEAST LOW LEVEL FLOW AND ABUNDANT MOISTURE IN THE LOWEST 2 KM.
WILL KEEP LIKELY POPS THROUGH THE EVENING... THEN WE SHOULD SEE
LIGHT RAIN START TO TREND DOWN TO MOSTLY DRIZZLE AND JUST PATCHY
LIGHT RAIN SOUTHWEST TO NORTHEAST OVERNIGHT. LOWS 45-54 WITH CLOUDY
SKIES.
FOR MONDAY: BASED ON AN AVERAGE LOW POSITION FROM THE CANADIAN/GFS/
ECMWF... THE COASTAL LOW IS LIKELY TO BE OVER THE CENTRAL COASTAL
AREA OF NC MONDAY MORNING... HEADING NORTHEAST ALONG WITH THE AXIS
OF THE SHORTWAVE TROUGH. WILL KEEP HIGH CHANCE POPS AND CLOUDS IN
THE MORNING WITH POPS TAPERING OFF IN THE AFTERNOON. WITH CLOUDS
HOLDING ON LONGER THAN EXPECTED... HAVE CUT BACK HIGHS TO 58-63.
FOR MONDAY NIGHT THROUGH THURSDAY: THE DETAILS OF THE MID-WEEK
FORECAST REMAIN MUDDIED BY DISAGREEMENT AMONG THE MODELS. THE
LONGWAVE PATTERN INDICATED BY THE GFS/ECMWF/CANADIAN TRENDS TOWARD
DEEP TROUGHING DEVELOPING OVER THE MISS VALLEY AND INTERIOR EASTERN
STATES BY THURSDAY. THERE MAY BE A RESIDUAL BAROCLINIC ZONE NEAR OR
JUST OFF THE SOUTHEAST COAST... BUT OVERALL THE OPPORTUNITY FOR ANY
SIGNIFICANT MOISTURE INTO NC APPEARS TO BE LACKING AS WEAK HIGH
PRESSURE BUILDS INTO AND OVER THE AREA FROM THE WEST. WILL KEEP THE
FORECAST MAINLY DRY THROUGH THURSDAY. LOW LEVEL THICKNESSES HOLD
NEAR TO JUST ABOVE NORMAL... THUS WILL HAVE TEMPERATURES FOLLOWING
SUIT WITH HIGHS MOSTLY AROUND 60 TO THE LOWER 60S. -GIH
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1230 AM FRIDAY...
WIDESPREAD LIFR VISIBILITIES EXPECTED THROUGH 12Z OVER MOST OF
CENTRAL NC AS DRIER AIR ALOFT AS CLEARED OUT CLOUDS. RESIDUAL NEAR
SURFACE MOISTURE HAS ALLOWED FOG AND LOW STRATUS TO DEVELOP. EXPECT
VISIBILITIES AT OR BELOW A MILE WITH VISIBILITIES BELOW A HALF MILE
QUITE COMMON. AS DRIER AIR GRADUALLY MIXES TOWARD THE SURFACE AFTER
09Z...EXPECT VISIBILITIES TO IMPROVE FROM WEST TO EAST.
AFTER 13Z...DRIER AIR THROUGHOUT THE ENTIRE ATMOSPHERE SHOULD RESULT
IN CLEAR OR MOSTLY CLEAR SKIES. NEAR SURFACE WINDS WILL BE NORTHERLY
AROUND 10 KTS WITH INFREQUENT GUSTS 16-19KTS THROUGH 18Z. AS HIGH
PRESSURE BUILDS FARTHER INTO THE REGION...WINDS WILL GRADUALLY
SUBSIDE.
VFR CONDITIONS WILL PERSIST FRIDAY NIGHT INTO SATURDAY WITH ONLY
PATCHES OF HIGH CLOUDS EXPECTED AND WINDS RELATIVELY LIGHT AND
VARIABLE.
A STORM SYSTEM WILL APPROACH FROM THE SW SATURDAY NIGHT AND AFFECT
THE REGION SUNDAY THROUGH MONDAY MORNING...BRINGING MVFR OR IFR
CONDITIONS.
VFR CONDITIONS RETURN TO THE AREA LATE MONDAY AND PERSIST INTO
TUESDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM EST FRIDAY FOR NCZ007>011-
023>028-040>043-075>078-085-086-088-089.
DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
NCZ073-074-083-084.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...WSS
000
FXUS62 KMHX 200751
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
251 AM EST FRI NOV 20 2009
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE OFFSHORE TODAY. HIGH PRES WILL BUILD
IN FROM THE N TONIGHT AND SAT...THEN SLIDE OFFSHORE SAT NIGHT. LOW
PRES WILL APPROACH FROM THE SW SUNDAY AND MOVE NE NEAR OR JUST
OFFSHORE OF THE COAST SUN NIGHT INTO MON. HIGH PRESSURE WILL
REBUILD OVER THE AREA TUESDAY THROUGH LATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 230 AM FRIDAY...WEAK BOUNDARY IS SLOWLY APPROACHING THE COAST
WITH SOME ISOLD SHRA OVER NRN TIER AND CSTL WTRS. MDLS SHOW BEST
CHCS OF SHRA ALONG IMD CST AFTER 12Z SO KEPT SMALL POP IN THESE
AREA THROUGH THE MORNING. WIDESPREAD CLOUD COVER OVER THE REGION
HAS LIMITED FOG DEVELOPMENT SO FAR TONIGHT. WITH BOUNDARY MOVING
SLOWLY EXPECT CLOUDS TO LINGER MOST AREAS THROUGH DAY BREAK AND
THIS WILL LIMIT POTENTIAL FOR WIDESPREAD DENSE FOG. WILL CONT TO
MONITOR NEXT CPL HOURS BUT LOOKS LIKE WILL BE ABLE TO DROP DENSE
FOG ADVISORY EARLY. WITH SOME SUNSHINE DEVELOPING TODAY SHLD SEE
HIGHS IN THE MID TO UPR 60S.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 230 AM FRIDAY...HIGH PRESSURE WILL BUILD N OF THE REGION
TONIGHT AND SAT WITH DRY WEATHER. SHLD HAVE GOOD RADIATIONAL
COOLING TONIGHT WITH LOWS IN THE LOW TO MID 40S COOLER INLAND
SPOTS. HIGHS SAT WITH PLENTY OF SUN SHLD REACH THE LOW TO MID 60S.
AS HIGH MOVES OFFSHORE TO THE N SAT NIGHT WILL SEE INCREASING
MOISTURE AS LOW LVL FLOW BECOMES MORE ONSHORE. OVERALL ATMS IS DRY
TO START SO NOT LOOKING FOR MUCH RAIN TO DEVELOP SAT
NIGHT...MAINLY LATE NEAR THE COAST. APPROACHING SRT WAVE COMBINED
WITH INCREASING ISENT LIFT SHLD LEAD TO DECENT CVRG OF RAIN SUNDAY
INTO SUNDAY NIGHT. FOR NOW WILL LEAN MORE TWRD NAM/EMCWF KEEPING
MAINLY NE FLOW OVER THE REGION WITH LOW PRES NEAR OR JUST OFF THE
CST LATER SUN INTO MON. THIS WILL ALSO KEEP RAIN THREAT GOING
LONGER THAN PREV FCST INDICATED SO INCREASED POPS TO LIKELY SUN
NIGHT ALL AREAS AND CONT LIKELY INTO MON MORN OVER THE ERN HALF OF
THE AREA. CLOUDS AND PRECIP WILL LIMIT HIGHS TO LOW TO POSS MID
60S SUNDAY AND MON.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AS OF 230 AM FRIDAY...HIGH PRES WILL BUILD IN TUE AND WED WITH DRY
WEATHER. COLD FRONT EXPECTED TO CROSS LATER WED OR EARLY THU AND
MAY SEE SOME RAIN FROM THIS BUT WILL NOT CHANGE CURRENT DRY FCST
UNTIL HAVE MORE CONFIDENCE.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
AS OF 900 PM THURSDAY...THE WEAK FRONT IS CURRENTLY OVER CENTRAL
NC WITH A FEW ISOLATED HEAVY SHOWERS OCCURRING ALONG IT AS WELL AS
NEAR THE COAST. THERE WILL BE A SMALL RISK OF AN ISOLATED SHOWER
AT THE TAF SITES THROUGH 09Z BY WHICH TIME THE FRONT SHOULD BE
EAST OF THE SITES. OF GREATER CONCERN IS THE POTENTIAL FOR
WIDESPREAD DENSE FOG OVERNIGHT. ALL OF THE AVIATION GUIDANCE IS IN
EXCELLENT AGREEMENT ON THIS. THE UPS FOG TOOL ALSO WAS INDICATING
A POTENTIAL FOR DENSE FOG. THE FOG SHOULD BEGIN EARLY TOO AS
TEMP/DEWPOINT DEPRESSIONS WERE VERY LOW THIS EVENING. LIMITING
FACTOR INITIALLY WILL BE THE PATCHY LOW CLOUDS OCCURRING AHEAD OF
THE FRONT BUT WHERE BREAKS IN THE CLOUDS HAVE OCCURRED VISIBILITIES
HAVE DROPPED TO IFR. THE FOG COULD END A LITTLE EARLIER THAN USUAL
FRIDAY MORNING AS THE NAM-12 IS INDICATING SURFACE WINDS AROUND 10
AROUND 12Z.
VFR CONDITIONS EXPECTED FRI INTO EARLY SUN. A COASTAL LOW WILL
LIKELY BRING REDUCED CIGS SUN AFTERNOON INTO EARLY MON.
&&
.MARINE...
AS OF 900 PM THURSDAY...WINDS HAVE DIMINISHED TO 10 KT OR LESS
EXCEPT FOR THE OUTER WATERS WHERE THEY WERE STILL BLOWING AROUND
15 KT. SEAS WERE STILL IN THE 5-7 FT CENTRAL/NORTH AND 4-6 FT
SOUTH RANGE THOUGH SO NO CHANGES TO CURRENT ADVISORIES. THE FRONT
SHOULD BE THROUGH THE SOUTHERN WATERS AROUND 09Z AND THE
CENTRAL/NORTHERN WATERS AROUND 12Z. LIGHT SOUTHERLY FLOW WILL
BRIEFLY SURGE TO NORTH AROUND 20 KT NORTHERN/CENTRAL WATERS FRIDAY
MORNING AND AROUND 15 KT SOUTH. OFFSHORE FLOW IN THE WAKE OF THE COLD
FRONT WILL HELP TO REDUCE SEAS A BIT MORE FRI THROUGH SAT AHEAD OF
A COASTAL LOW AND EXPECT A PERIOD OF SUB SCA CONDITIONS SAT NIGHT
AND EARLY SUN. MODELS CONTINUE TO WAVER ON THE TRACK OF THE LOW
WITH THE NEXT SYSTEM AND WILL MAINTAIN CONTINUITY IN TRACKING THE
LOW OFFSHORE SUN/SUN NIGHT. A PERIOD OF SCA CONDITIONS LIKELY
ACROSS MOST OF THE WATERS LATE IN THE WEEKEND AND EARLY NEXT WEEK
ASSOC WITH THE LOW.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ029-
044>047-079>081-090>095-098.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST SATURDAY NIGHT FOR
AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR AMZ156.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ150.
SMALL CRAFT ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
AMZ158.
&&
$$
SYNOPSIS...RF
NEAR TERM...RF
SHORT TERM...RF
LONG TERM...RF
AVIATION...JME/SK
MARINE...JME/SK
000
FXUS62 KRAH 200544
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1243 AM EST FRI NOV 20 2009
.SYNOPSIS...
A COLD FRONT OVER WESTERN NC WILL PUSH EAST OVERNIGHT.
HIGH PRESSURE WILL THEN EXPAND INTO THE REGION THROUGH SATURDAY...
IN ADVANCE OF THE NEXT STORM SYSTEM EXPECTED TO ARRIVE ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM THURSDAY...
...DENSE FOG ADVISORY FOR ALL OF CENTRAL NC TONIGHT...
BROKEN LINE OF SHOWERS MOVING EAST INTO COASTAL SECTIONS OF THE
STATE IS ASSOCIATED WITH THE MERGED WEDGE FRONT/COASTAL TROUGH
BOUNDARY. ONLY ONE STORM BRIEFLY EXHIBITED SOME WEAK ROTATION (NEAR
THE DURHAM/WAKE COUNTY LINE)AS IT TRACKED ALONG THE WEDGE TMB...BUT
INSUFFICIENT INSTABILITY PREVENTED ANY ORGANIZED/SUSTAINED COUPLET
FROM HOLDING TOGETHER AS MLCAPES WERE 250 JOULES OR LESS ACROSS THE
CENTRAL PIEDMONT. THE BROKEN CONVECTIVE LINE ASSOCIATED WITH MERGED
WEDGE FRONT IS CURRENTLY PUSHING INTO A SLIGHTLY MORE FAVORABLE
ENVIRONMENT WITH MLCAPES AROUND 500 JOULES...SO WILL CONTINUE TO
MONITOR RADAR FOR THE POTENTIAL FOR ANY BRIEF SPIN UPS AS LCLS
REMAIN LOW AOA 500 M.
ONCE THIS LINE PUSHES EAST OF THE AREA...RAIN CHANCES WILL BE PRETTY
MUCH OVER EVEN WITH THE COLD FRONT PASSAGE PROGGED TO MOVE THROUGH
THE AREA LATER TONIGHT...BETWEEN 06 TO 12Z. THE FORECAST CHALLENGE
THEN TURNS TOWARDS THE DURATION AND EXTENT OF DENSE FOG...AS WE ARE
ALREADY SEEING DENSE FOG DEVELOP ACROSS THE FOOTHILLS AND WESTERN
PIEDMONT...EAST OF THE COLD FRONT WHERE CLEARING HAS TAKEN PLACE.
CURRENT THINKING IS THAT DUE TO THE TARDINESS OF THE FROPA AND
ACCOMPANYING DRY AIR ADVECTION...DENSE FOG WILL BE WIDESPREAD ACROSS
THE EASTERN TWO-THIRDS OF THE FORECAST AREA...FROM THE TRIANGLE
EAST. TOUGHER CALL ACROSS THE WESTERN PIEDMONT WHERE THE EARLIER
ARRIVAL OF THE FROPA BETWEEN 06 TO 09Z WILL CERTAINLY
IMPROVE/DISSIPATE THE FOG.
WILL GO AHEAD AND ISSUE A DENSE FOG ADVISORY (DFA) FOR ALL OF
CENTRAL NC OVERNIGHT...SEGMENTING THE ADVISORY TO ACCOUNT FOR THE
TIMING OF THE FROPA AND IMPROVING CONDITIONS FROM WEST TO EAST
ACROSS THE AREA. THE DFA WILL END AT 6 AM EST FOR THE WESTERN
PIEDMONT INCLUDING THE TRIAD. WILL DELAY THE START TIME FOR THE
DFA FOR CENTRAL AND EASTERN SECTIONS UNTIL MIDNIGHT...AND ENDING AT
9 AM EST.
A WIDE RANGE IN OVERNIGHT LOWS TONIGHT DUE TO THE TIMING OF THE
FROPA...LOWS IN THE MID 40S NW TO MID/UPPER 50S EAST.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 250 PM THURSDAY...
FOR FRIDAY THROUGH SATURDAY: THE COLD FRONT SHOULD BE SHIFTING OFF
THE COAST BY FRIDAY MORNING. WITH RATHER LIGHT SURFACE WINDS BEHIND
THE FRONT AND PLENTY OF RESIDUAL NEAR-SURFACE MOISTURE... EXPECT
PATCHES OF FOG TO PERSIST PAST DAYBREAK. OTHERWISE... EXPECT A BRIEF
PERIOD OF QUIET WEATHER HEADING INTO SATURDAY. THE SURFACE HIGH
DRIFTS NORTH-NORTHEAST THROUGH THE OH VALLEY FRIDAY AS IT BEGINS TO
BUILD INTO NC. WITH A MAINLY FLAT SOUTHWEST MID LEVEL FLOW OVER THE
INTERIOR SOUTHEAST... FORECAST SOUNDINGS SHOW STABLE SUBSIDING AIR
ALOFT AND A DRY COLUMN. MODEL FORECAST LOW LEVEL THICKNESSES ARE
JUST SLIGHTLY ABOVE NORMAL... AND FACTORING IN PLENTY OF SUNSHINE
ALONG WITH UPSTREAM TEMPS AND THE MILD NATURE OF THE INCOMING AIR
MASS... EXPECT HIGHS OF 62-68. THE HIGH CENTER MOVES OVER WV FRIDAY
NIGHT AND CONTINUES RIDGING INTO NC... CAUSING SURFACE WINDS TO VEER
AROUND TO NORTH-NORTHEAST AND PULL IN COOLER AIR. FORECAST SOUNDINGS
SHOW SOME INCREASE IN HIGH CLOUDS OVERNIGHT AHEAD OF THE NEXT STORM
SYSTEM PUSHING INTO THE SOUTHERN PLAINS/WEST GULF REGION... HOWEVER
THESE APPEAR TO BE THIN ENOUGH TO HAVE MINIMAL IMPACT ON GROUND HEAT
LOSS. NUDGED LOWS DOWN A DEGREE OR SO TO 37-44. MID-UPPER LEVEL
MOISTURE STEADILY INCREASES AND DEEPENS SATURDAY AS THE MID LEVEL
VORTEX CROSSES LA INTO MS. THE SURFACE HIGH TO OUR NORTH PASSES
SLOWLY NORTHWARD TO THE OH/PA BORDER AND BECOMES SUPPORTED BY
CONFLUENT FLOW ALOFT WITH NORTHERN STREAM SHORTWAVE TROUGHING OVER
PA... AND THIS SHOULD ENSURE A STEADY FEED OF LOW LEVEL DRY AIR INTO
CENTRAL NC... SETTING US UP FOR DAMMING ONCE THE SURFACE HIGH CAN
GET INTO A MORE FAVORABLE POSITION (OVER THE ST LAWRENCE VALLEY)
SATURDAY NIGHT WHERE IT CAN TAP INTO EVEN COOLER AIR AND STRENGTHEN
FURTHER AND SUPPORT ALOFT PERSISTS. HIGHS SATURDAY 60-65 WITH
INCREASING AND THICKENING CLOUDS.
FOR SATURDAY NIGHT/SUNDAY: MODELS AGREE FAIRLY WELL ON THE MID LEVEL
SHORTWAVE TROUGH DEAMPLIFYING A BIT AS IT LIFTS WITH A NEGATIVE TILT
FROM NORTHEAST LA TO NORTHEAST MS SATURDAY NIGHT... WITH A STEADY
LOWERING OF THE CLOUD BASE OVER NC OVERNIGHT. ISENTROPIC UPGLIDE
COMMENCES OVER SOUTHERN NC LATE... HOWEVER THE LATEST MODEL GUIDANCE
SUGGESTS THAT MOST PRECIP WILL HOLD OFF UNTIL AT LEAST SUNDAY
MORNING. TYPICALLY... WITH ANOMALOUSLY LOW PRESSURE AREAS NEAR THE
GULF COAST REGION SUCH AS THIS... WE SEE SUBSTANTIAL CONVECTION IN
THE WARM SECTOR... FROM THE NORTHEAST GULF NORTHWARD INTO THE
EASTERN GULF STATES/GA... SOUTH OF THE WEDGE WARM FRONT WHICH IS
LIKELY TO EXTEND ACROSS CENTRAL GA AND SOUTHERN SC HEADING INTO
SUNDAY MORNING. GIVEN THAT THE BEST MOISTURE TRANSPORT WILL OCCUR
FROM THE NORTHEAST GULF UP AND OVER THIS WARM FRONT WHERE LOW LEVEL
MASS CONVERGENCE IS MAXIMIZED... AND CONSIDERING THE DRY SUBCLOUD
LAYER NOTED ON FORECAST SOUNDINGS... WE ARE LIKELY TO SEE ONLY VERY
LIGHT RAIN (IF ANYTHING) SATURDAY NIGHT. HAVE TRIMMED BACK POPS TO
LOW CHANCE AND CUT AMOUNTS DOWN TO JUST A FEW HUNDREDTHS THROUGH
DAYBREAK. LOWS 42-47. AS THE MID LEVEL LOW TRACKS UP THROUGH TN INTO
KY SUNDAY (A FARTHER-WEST TRACK THAN WHAT WAS SEEN ON YESTERDAY`S
MODELS)... EXPECT A MILLER TYPE B PATTERN TO DEVELOP WITH THE
PRIMARY LOW WELL WEST OF THE SOUTHERN APPALACHIANS AND SECONDARY LOW
PRESSURE DEVELOPING OFF THE CAROLINA COAST. ALONG WITH THE QUICKLY
SATURATING COLUMN (PRECIP WATER RISING TO 250% OF NORMAL)... FORCING
FOR ASCENT IMPROVES WITH DEEPENING AND STRENGTHENING ISENTROPIC
UPGLIDE... MID LEVEL HEIGHT FALLS... AND INCREASED OVERRUNNING WITH
30-35 KTS OF SOUTHERLY FLOW ATOP THE COOL DOME ASSOCIATED WITH THE
APPROACH FROM THE SOUTH OF THE 850 MB WARM FRONT. WILL HOLD ONTO
LIKELY POPS FOR SUNDAY. HOWEVER... WHILE THE DEEP SATURATION AND
FORCING MAKE LIGHT RAIN LIKELY... AMOUNTS ARE PROBLEMATIC TO
DETERMINE. UPPER DIVERGENCE IN THE LEFT EXIT REGION OF THE
SUBTROPICAL JET IS DECENT... BUT THE GREATEST DPVA HOLDS TO OUR
WEST. THE LATEST NAM SHOWS DRIER AIR ABOVE 0C AS COMPARED TO THE
GFS... AND IT FOCUSES MOST OF THE PRECIP AWAY FROM THE WEDGE... WELL
TO OUR WEST OVER THE MOUNTAINS AND OVER THE GULF STREAM. THE SREF
MEAN IS ALSO HINTING AT LESSER AMOUNTS WITH FAIRLY LOW PROBABILITY
OF MORE THAN 0.05" OF RAIN THROUGH EARLY SUNDAY EVENING... HOWEVER
THE GEFS MEAN HAS TRENDED WETTER. WILL KEEP TOTAL AMOUNTS AROUND A
QUARTER TO THIRD INCH FOR NOW. WITH CHILLY NORTHEAST WINDS AND NO
MECHANISMS TO DISLODGE THE COOL STABLE SURFACE BASED LAYER...
PIEDMONT TEMPS MAY STRUGGLE TO RISE... AND HAVE HELD CLOSE TO THE
EARLIER FORECAST... WITH HIGHS 48 TO 57. -GIH
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 255 PM THURSDAY...
FOR SUNDAY NIGHT: THE PRIMARY SURFACE LOW TO OUR WEST IS EXPECTED TO
HEAD INTO THE OHIO VALLEY AND WEAKEN WHILE THE SECONDARY LOW TREKS
UP INTO EASTERN NC. WE DRY OUT ABOVE THE FREEZING LEVEL AS THE MID
LEVEL DRY SLOT NOSES IN FROM THE SOUTHWEST... LEAVING A BRISK
NORTHEAST LOW LEVEL FLOW AND ABUNDANT MOISTURE IN THE LOWEST 2 KM.
WILL KEEP LIKELY POPS THROUGH THE EVENING... THEN WE SHOULD SEE
LIGHT RAIN START TO TREND DOWN TO MOSTLY DRIZZLE AND JUST PATCHY
LIGHT RAIN SOUTHWEST TO NORTHEAST OVERNIGHT. LOWS 45-54 WITH CLOUDY
SKIES.
FOR MONDAY: BASED ON AN AVERAGE LOW POSITION FROM THE CANADIAN/GFS/
ECMWF... THE COASTAL LOW IS LIKELY TO BE OVER THE CENTRAL COASTAL
AREA OF NC MONDAY MORNING... HEADING NORTHEAST ALONG WITH THE AXIS
OF THE SHORTWAVE TROUGH. WILL KEEP HIGH CHANCE POPS AND CLOUDS IN
THE MORNING WITH POPS TAPERING OFF IN THE AFTERNOON. WITH CLOUDS
HOLDING ON LONGER THAN EXPECTED... HAVE CUT BACK HIGHS TO 58-63.
FOR MONDAY NIGHT THROUGH THURSDAY: THE DETAILS OF THE MID-WEEK
FORECAST REMAIN MUDDIED BY DISAGREEMENT AMONG THE MODELS. THE
LONGWAVE PATTERN INDICATED BY THE GFS/ECMWF/CANADIAN TRENDS TOWARD
DEEP TROUGHING DEVELOPING OVER THE MISS VALLEY AND INTERIOR EASTERN
STATES BY THURSDAY. THERE MAY BE A RESIDUAL BAROCLINIC ZONE NEAR OR
JUST OFF THE SOUTHEAST COAST... BUT OVERALL THE OPPORTUNITY FOR ANY
SIGNIFICANT MOISTURE INTO NC APPEARS TO BE LACKING AS WEAK HIGH
PRESSURE BUILDS INTO AND OVER THE AREA FROM THE WEST. WILL KEEP THE
FORECAST MAINLY DRY THROUGH THURSDAY. LOW LEVEL THICKNESSES HOLD
NEAR TO JUST ABOVE NORMAL... THUS WILL HAVE TEMPERATURES FOLLOWING
SUIT WITH HIGHS MOSTLY AROUND 60 TO THE LOWER 60S. -GIH
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1230 AM FRIDAY...
WIDESPREAD LIFR VISIBILITIES EXPECTED THROUGH 12Z OVER MOST OF
CENTRAL NC AS DRIER AIR ALOFT AS CLEARED OUT CLOUDS. RESIDUAL NEAR
SURFACE MOISTURE HAS ALLOWED FOG AND LOW STRATUS TO DEVELOP. EXPECT
VISIBILITIES AT OR BELOW A MILE WITH VISIBILITIES BELOW A HALF MILE
QUITE COMMON. AS DRIER AIR GRADUALLY MIXES TOWARD THE SURFACE AFTER
09Z...EXPECT VISIBILITIES TO IMPROVE FROM WEST TO EAST.
AFTER 13Z...DRIER AIR THROUGHOUT THE ENTIRE ATMOSPHERE SHOULD RESULT
IN CLEAR OR MOSTLY CLEAR SKIES. NEAR SURFACE WINDS WILL BE NORTHERLY
AROUND 10 KTS WITH INFREQUENT GUSTS 16-19KTS THROUGH 18Z. AS HIGH
PRESSURE BUILDS FARTHER INTO THE REGION...WINDS WILL GRADUALLY
SUBSIDE.
VFR CONDITIONS WILL PERSIST FRIDAY NIGHT INTO SATURDAY WITH ONLY
PATCHES OF HIGH CLOUDS EXPECTED AND WINDS RELATIVELY LIGHT AND
VARIABLE.
A STORM SYSTEM WILL APPROACH FROM THE SW SATURDAY NIGHT AND AFFECT
THE REGION SUNDAY THROUGH MONDAY MORNING...BRINGING MVFR OR IFR
CONDITIONS.
VFR CONDITIONS RETURN TO THE AREA LATE MONDAY AND PERSIST INTO
TUESDAY AS HIGH PRESSURE BUILDS IN FROM THE WEST.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM EST FRIDAY FOR NCZ007>011-
023>028-040>043-075>078-085-086-088-089.
DENSE FOG ADVISORY UNTIL 6 AM EST FRIDAY FOR NCZ021-022-038-
039-073-074-083-084.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...WSS
000
FXUS62 KILM 200537
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1237 AM EST FRI NOV 20 2009
.SYNOPSIS...
SHOWERS WILL END OVERNIGHT WITH AREAS OF DENSE FOG SETTLING ACROSS
THE REGION THROUGH DAYBREAK. HIGH PRESSURE WILL BUILD...THEN PASS
NORTH OF THE AREA...BRINGING DRY WEATHER TODAY THROUGH SATURDAY. LOW
PRESSURE EMERGING FROM THE GULF OF MEXICO WILL BRING A GOOD CHANCE
OF RAIN TO THE EASTERN CAROLINAS SATURDAY NIGHT THROUGH SUNDAY
NIGHT...PULLING AWAY FROM THE REGION MONDAY. DRY AND MILD WEATHER
IS EXPECTED IN WAKE OF THIS SYSTEM TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM THURSDAY...DENSE FOG ADVISORY HAS BEEN ISSUED FOR THE
ENTIRE ILM CWA FROM MIDNIGHT THROUGH 9 AM. WEAK FRONTAL BOUNDARY
SLOWLY PUSHING ACROSS THE AREA...DIFFICULT TO DISCERN SFC PRESSURE
PATTERN-WISE BUT DOES EXIST IF USING LATEST OBSERVED SFC WINDS AND
CLOUD IMAGERY TRENDS. SHORT TERM MODELS SLOWLY PUSH THIS BOUNDARY
EAST OF THE AREA THIS EVENING AND EARLY THIS MORNING. CLEARING
BEHIND THE BOUNDARY HAS BEEN QUICKLY FILLED IN BY FOG/DENSE FOG AND
WILL BE THE MAIN-STAY FOR THE OVERNIGHT PERIOD THROUGH EARLY FRIDAY
MORNING. LATEST NAMBUFR SOUNDINGS DO SUPPORT THE ARGUMENT FOR DENSE
FOG AND SEE NO REASON TO RULE AGAINST. MUCH OF THE CAPE FOR SHRA
ACTIVITY OVER LAND FROM THE DAYS INSOLATION IS OVERWEIGHT AND WILL
THERE4 REMOVE ANY POPS LEFTOVER LAND AREAS OF THE ILM CWA. THE
EXCEPTION WILL BE FOR THE COASTAL COUNTIES DUE TO ANY PCPN THAT
MOVES ONSHORE DURING THIS EVENING/OVERNIGHT. COULD OBSERVE A DECENT
RANGE OF MIN TEMPS ACROSS THE CWA WITH UPPER 50S AT THE IMMEDIATE
COAST TO MID 40S WITHIN DRIER AIR ACROSS THE EXTREME NW PORTION OF
THE ILM CWA.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2:30 PM THURSDAY...SPLIT FLOW AT THE MID LEVELS WILL BRING A
STORM SYSTEM ACROSS THE AREA LATE IN THE PERIOD WHICH WILL BE THE
FOCUS OF THIS FORECAST. IS APPEARS THE TIMING HAS BEEN DELAYED EVER
SO SLIGHTLY IN BOTH THE GFS AND NAM ALTHOUGH THE NAM IS GENERATING A
STRONGER LOW ALONG AN OLD FRONTAL BOUNDARY THAT WILL RESIDE OFFSHORE
WHILE THE GFS IS MORE RESERVED. OVERALL HAVE BACKED OFF ON POPS FOR
SATURDAY AFTERNOON AND EVENING. SHOULD SEE MORE SUN SATURDAY AS WELL
AND HAVE ADJUSTED MAX TEMPERATURES UP SLIGHTLY. AS FOR
FRIDAY...SHOULD SEE A MOSTLY SUNNY DAY WITH HIGH TEMPERATURES AROUND
70 TO THE LOWER 70S IN GEORGETOWN AND WILLIAMSBURG COUNTIES.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 2:30 PM THURSDAY...SOUTHERN BRANCH STORM SYSTEM WITH GOOD GULF
OF MEXICO MOISTURE CONNECTION WILL AFFECT THE AREA SUNDAY INTO
SUNDAY NIGHT. INITIAL SURFACE WAVE WILL APPROACH FROM THE CENTRAL
GULF COAST AND OVERRUN THE SURFACE WEDGE IN PLACE. SUNDAY NIGHT HAS
THE STORM JUMP THE WEDGE AND DEVELOP A SECONDARY LOW OFF THE
CAROLINA COAST. 850MB MAY MAX OUT AS HIGH AS 45 KT LEADING TO STRONG
ISENTROPIC UPGLIDE AND A GOOD HALF INCH TO INCH OF RAINFALL STILL
APPEARS TO BE A GOOD AREAL AVERAGE FORECAST. DRY AIR WILL WRAP IN
BEHIND THE LOW ON MONDAY ALTHOUGH THE DAY MAY START OUT WITH CLOUDS
AND DRIZZLE. LOW AMPLITUDE ALOFT AND NO REAL COLD ADVECTION SO
MONDAY PM SHOULD END UP MUCH MILDER THAN SUNDAYS COOL READINGS. THE
MIDWEEK PERIOD OF TUESDAY AND WEDNESDAY WILL BRING WEAK HIGH
PRESSURE BUILDING IN FROM THE NORTH. THE NORTHERN BRANCH WILL HAVE
SOME FAIRLY STRONG AND PROGRESSIVE TROUGHS BUT THEY WILL BYPASS THE
FORECAST AREA FAR ENOUGH TO THE NORTH TO PREVENT BRINGING ANY
WEATHER. TEMPS SHOULD BE FAIRLY SEASONABLE. A LITTLE PHASING IN OF
THE POLAR JET COULD DRIVE A COLD FRONT ACROSS THE AREA BY THURSDAY
BRINGING IN SOME CHILLY WEATHER. THE BOUNDARY ITSELF WILL BE
MOISTURE-STARVED AND WILL LIKELY NOT BRING RAIN CHANCES. &&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
LOOKS LIKE FOG/STRATUS WILL SET UP OVER MOST OF THE REGION
TONIGHT...WITH POTENTIALLY LOW VISIBILITIES. ATMOSPHERE SHOULD MIX
OUT FAIRLY QUICKLY TOMORROW WITH VFR EXPECTED AT ALL TERMINALS BY
MID MORNING. HIGH PRESSURE WILL CONTINUE TO BUILD IN ALL DAY WITH A
NORTH NORTHEAST WIND...A BIT GUSTY IN THE AFTERNOON.
EXTENDED OUTLOOK...VFR FRIDAY/SATURDAY. SHOWERS AND LOW CEILINGS
MOVE BACK IN SATURDAY NIGHT THROUGH MONDAY MORNING.
$$
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM THURSDAY...MSAS INDICATES SFC LOW CONTINUES JUST
OFFSHORE FROM THE ILM COASTAL WATERS. CONTINUOUS BLOWUP OF STRONGER
CONVECTION WILL REMAIN OVER THE WARMER SSTS OF THE GULF STREAM
WATERS AS HAS BEEN THE CASE DURING THIS EVENING. THE STRONGER SE
WINDS WITHIN THE WARM SECTOR HAVE CONTINUED TO PUSH 4 TO 5 FOOT SEAS
INTO THE ILM COASTAL WATERS NORTH OF LITTLE RIVER INLET...WITH
FRYING PAN SHOALS BUOY HAVING BREACHED 6 FEET AT TIMES AND THE BUOY
10 MILES SE OF WRIGHTSVILLE BEACH AT 5 FEET. WITH WINDS OVER THE
WATERS TO REMAIN WELL BELOW 15 KT SUSTAINED...WILL HOLD OFF WITH THE
SCEC FOR THESE WATERS FOR THE TIME BEING. THE WATERS SOUTH OF THE
LITTLE RIVER INLET REMAIN MUCH MORE BENIGN WITH SEAS ABOUT 1 FOOT
LESS AND WINDS BECOMING NW-N 10 TO POSSIBLY 15 KT BY MORNING. ALONG
THE IMMEDIATE COAST...THE INLETS AND INTRACOASTAL WATERWAY COULD
OBSERVE REDUCED VSBY FROM FOG...POSSIBLY DENSE...DEPENDING WHAT THE
UNDERLYING SST HAVE BECOME.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2:30 PM THURSDAY...HIGH PRESSURE MOVING ACROSS THE MIDWEST
WILL BE THE DOMINANT WEATHER FEATURE THROUGH THE SHORT TERM.
INITIALLY WINDS WILL BE FROM THE NORTHWEST AROUND 15 KNOTS. THE
DIRECTION WILL VEER TO MORE OF A NORTHEASTERLY DIRECTION BY SATURDAY
MORNING. A NE FLOW WILL PREVAIL AND INTENSIFY A BIT AS LOW PRESSURE
DEVELOPS OVER THE LOWER MISSISSIPPI VALLEY AND THE HIGH BEGRUDGINGLY
HOLDS ON. SEAS...ESPECIALLY ACROSS THE OUTER WATERS...MAY
OCCASIONALLY REACH SCEC CRITERIA WITH THE PROLONGED FETCH. CLOSER TO
SHORE...A MORE MANAGEABLE 2-3 FEET WILL PREVAIL.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 2:30 PM THURSDAY...SUNDAY SHOULD BRING THE MOST INCLEMENT
WEATHER OF THE LONG TERM PD. A STORM SYSTEM MOVING OUT OF THE GULF
OF MEXICO WILL PINCH THE GRADIENT AS SURFACE HIGH TO THE NORTH HANGS
ON. SUNDAY NIGHT A WEAKER SECONDARY LOW SHOULD FORM OFF THE COAST
AND MOVE TO THE NORTHEAST. THIS IS COMPLICATING THE FORECAST AS IT
IS UNCERTAIN WHETHER THIS LOW WILL TRAVEL OFFSHORE OR UP THE COAST
BUT OVER LAND. AHEAD OF THE SYSTEM SUNDAY MAY REQUIRE SMALL CRAFT
ADVISORY TO DUE 6 FT SEAS. NORTHWEST TO WESTERLY WINDS WILL BE FOUND
BEHIND THE STORM FROM MONDAY AND BEYOND. WINDS AND SEAS WILL QUICKLY
SETTLE ON MONDAY AND REMAIN IN THE 2 TO 3 FT RANGE IN THE OFFSHORE
FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 9 AM EST FRIDAY FOR SCZ017-023-024-
032>034-039-046.
NC...DENSE FOG ADVISORY UNTIL 9 AM EST FRIDAY FOR NCZ087-096-097-
099>101.
MARINE...NONE.
&&
$$
NEAR TERM...DOUG/MIKE
SHORT TERM..STEPHEN
LONG TERM...MARK
AVIATION....DAVID/MIKE
000
FXUS62 KILM 200319
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
945 PM EST THU NOV 19 2009
.SYNOPSIS...
PRIME CONDITIONS HAVE DEVELOPED FOR DENSE FOG TO BECOME WIDESPREAD
ACROSS THE AREA AFTER A COLD FRONTAL PASSAGE OVERNIGHT. HIGH
PRESSURE WILL BUILD INTO THE AREA FROM THE OHIO RIVER VALLEY
FRIDAY...THEN RIDGE ACROSS THE AREA FROM THE NORTHEAST STATES ON
SATURDAY. LOW PRESSURE SYSTEM FROM THE GULF COAST STATES WILL IMPACT
THE AREA LATE SATURDAY INTO EARLY MONDAY FOLLOWED BY HIGH PRESSURE
FROM THE WEST INTO TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM THURSDAY...DENSE FOG ADVISORY HAS BEEN ISSUED FOR THE
ENTIRE ILM CWA FROM MIDNIGHT THROUGH 9 AM. WEAK FRONTAL BOUNDARY
SLOWLY PUSHING ACROSS THE AREA...DIFFICULT TO DISCERN SFC PRESSURE
PATTERN-WISE BUT DOES EXIST IF USING LATEST OBSERVED SFC WINDS AND
CLOUD IMAGERY TRENDS. SHORT TERM MODELS SLOWLY PUSH THIS BOUNDARY
EAST OF THE AREA THIS EVENING AND EARLY THIS MORNING. CLEARING
BEHIND THE BOUNDARY HAS BEEN QUICKLY FILLED IN BY FOG/DENSE FOG AND
WILL BE THE MAIN-STAY FOR THE OVERNIGHT PERIOD THROUGH EARLY FRIDAY
MORNING. LATEST NAMBUFR SOUNDINGS DO SUPPORT THE ARGUMENT FOR DENSE
FOG AND SEE NO REASON TO RULE AGAINST. MUCH OF THE CAPE FOR SHRA
ACTIVITY OVER LAND FROM THE DAYS INSOLATION IS OVERWEIGHT AND WILL
THERE4 REMOVE ANY POPS LEFTOVER LAND AREAS OF THE ILM CWA. THE
EXCEPTION WILL BE FOR THE COASTAL COUNTIES DUE TO ANY PCPN THAT
MOVES ONSHORE DURING THIS EVENING/OVERNIGHT. COULD OBSERVE A DECENT
RANGE OF MIN TEMPS ACROSS THE CWA WITH UPPER 50S AT THE IMMEDIATE
COAST TO MID 40S WITHIN DRIER AIR ACROSS THE EXTREME NW PORTION OF
THE ILM CWA.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2:30 PM THURSDAY...SPLIT FLOW AT THE MID LEVELS WILL BRING A
STORM SYSTEM ACROSS THE AREA LATE IN THE PERIOD WHICH WILL BE THE
FOCUS OF THIS FORECAST. IS APPEARS THE TIMING HAS BEEN DELAYED EVER
SO SLIGHTLY IN BOTH THE GFS AND NAM ALTHOUGH THE NAM IS GENERATING A
STRONGER LOW ALONG AN OLD FRONTAL BOUNDARY THAT WILL RESIDE OFFSHORE
WHILE THE GFS IS MORE RESERVED. OVERALL HAVE BACKED OFF ON POPS FOR
SATURDAY AFTERNOON AND EVENING. SHOULD SEE MORE SUN SATURDAY AS WELL
AND HAVE ADJUSTED MAX TEMPERATURES UP SLIGHTLY. AS FOR
FRIDAY...SHOULD SEE A MOSTLY SUNNY DAY WITH HIGH TEMPERATURES AROUND
70 TO THE LOWER 70S IN GEORGETOWN AND WILLIAMSBURG COUNTIES.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 2:30 PM THURSDAY...SOUTHERN BRANCH STORM SYSTEM WITH GOOD GULF
OF MEXICO MOISTURE CONNECTION WILL AFFECT THE AREA SUNDAY INTO
SUNDAY NIGHT. INITIAL SURFACE WAVE WILL APPROACH FROM THE CENTRAL
GULF COAST AND OVERRUN THE SURFACE WEDGE IN PLACE. SUNDAY NIGHT HAS
THE STORM JUMP THE WEDGE AND DEVELOP A SECONDARY LOW OFF THE
CAROLINA COAST. 850MB MAY MAX OUT AS HIGH AS 45 KT LEADING TO STRONG
ISENTROPIC UPGLIDE AND A GOOD HALF INCH TO INCH OF RAINFALL STILL
APPEARS TO BE A GOOD AREAL AVERAGE FORECAST. DRY AIR WILL WRAP IN
BEHIND THE LOW ON MONDAY ALTHOUGH THE DAY MAY START OUT WITH CLOUDS
AND DRIZZLE. LOW AMPLITUDE ALOFT AND NO REAL COLD ADVECTION SO
MONDAY PM SHOULD END UP MUCH MILDER THAN SUNDAYS COOL READINGS. THE
MIDWEEK PERIOD OF TUESDAY AND WEDNESDAY WILL BRING WEAK HIGH
PRESSURE BUILDING IN FROM THE NORTH. THE NORTHERN BRANCH WILL HAVE
SOME FAIRLY STRONG AND PROGRESSIVE TROUGHS BUT THEY WILL BYPASS THE
FORECAST AREA FAR ENOUGH TO THE NORTH TO PREVENT BRINGING ANY
WEATHER. TEMPS SHOULD BE FAIRLY SEASONABLE. A LITTLE PHASING IN OF
THE POLAR JET COULD DRIVE A COLD FRONT ACROSS THE AREA BY THURSDAY
BRINGING IN SOME CHILLY WEATHER. THE BOUNDARY ITSELF WILL BE
MOISTURE-STARVED AND WILL LIKELY NOT BRING RAIN CHANCES. &&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
SHOWERS OVER PORTIONS OF THE CWA WILL DISSIPATE EARLY IN THE
FORECAST PERIOD AS A TROUGH ROTATES NORTHEAST AND THE SURFACE BEGINS
TO RADIATE. GOOD LOW LEVEL MOISTURE AND LIGHT WINDS WILL SUPPORT
POSSIBLE HEAVY FOG AND LOW STRATUS AFTER MIDNIGHT. ATMOSPHERE DRIES
OUT SIGNIFICANTLY BY MID MORNING FRIDAY...WITH VFR CONDITIONS
EXPECTED. WINDS WILL BECOME NORTH NORTHEAST FRIDAY AS HIGH PRESSURE
BUILDS IN.
EXTENDED OUTLOOK...VFR FRIDAY/SATURDAY. SHOWERS AND LOW CEILINGS
MOVE BACK IN SATURDAY NIGHT THROUGH MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 945 PM THURSDAY...MSAS INDICATES SFC LOW CONTINUES JUST
OFFSHORE FROM THE ILM COASTAL WATERS. CONTINUOUS BLOWUP OF STRONGER
CONVECTION WILL REMAIN OVER THE WARMER SSTS OF THE GULF STREAM
WATERS AS HAS BEEN THE CASE DURING THIS EVENING. THE STRONGER SE
WINDS WITHIN THE WARM SECTOR HAVE CONTINUED TO PUSH 4 TO 5 FOOT SEAS
INTO THE ILM COASTAL WATERS NORTH OF LITTLE RIVER INLET...WITH
FRYING PAN SHOALS BUOY HAVING BREACHED 6 FEET AT TIMES AND THE BUOY
10 MILES SE OF WRIGHTSVILLE BEACH AT 5 FEET. WITH WINDS OVER THE
WATERS TO REMAIN WELL BELOW 15 KT SUSTAINED...WILL HOLD OFF WITH THE
SCEC FOR THESE WATERS FOR THE TIME BEING. THE WATERS SOUTH OF THE
LITTLE RIVER INLET REMAIN MUCH MORE BENIGN WITH SEAS ABOUT 1 FOOT
LESS AND WINDS BECOMING NW-N 10 TO POSSIBLY 15 KT BY MORNING. ALONG
THE IMMEDIATE COAST...THE INLETS AND INTRACOASTAL WATERWAY COULD
OBSERVE REDUCED VSBY FROM FOG...POSSIBLY DENSE...DEPENDING WHAT THE
UNDERLYING SST HAVE BECOME.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2:30 PM THURSDAY...HIGH PRESSURE MOVING ACROSS THE MIDWEST
WILL BE THE DOMINANT WEATHER FEATURE THROUGH THE SHORT TERM.
INITIALLY WINDS WILL BE FROM THE NORTHWEST AROUND 15 KNOTS. THE
DIRECTION WILL VEER TO MORE OF A NORTHEASTERLY DIRECTION BY SATURDAY
MORNING. A NE FLOW WILL PREVAIL AND INTENSIFY A BIT AS LOW PRESSURE
DEVELOPS OVER THE LOWER MISSISSIPPI VALLEY AND THE HIGH BEGRUDGINGLY
HOLDS ON. SEAS...ESPECIALLY ACROSS THE OUTER WATERS...MAY
OCCASIONALLY REACH SCEC CRITERIA WITH THE PROLONGED FETCH. CLOSER TO
SHORE...A MORE MANAGEABLE 2-3 FEET WILL PREVAIL.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 2:30 PM THURSDAY...SUNDAY SHOULD BRING THE MOST INCLEMENT
WEATHER OF THE LONG TERM PD. A STORM SYSTEM MOVING OUT OF THE GULF
OF MEXICO WILL PINCH THE GRADIENT AS SURFACE HIGH TO THE NORTH HANGS
ON. SUNDAY NIGHT A WEAKER SECONDARY LOW SHOULD FORM OFF THE COAST
AND MOVE TO THE NORTHEAST. THIS IS COMPLICATING THE FORECAST AS IT
IS UNCERTAIN WHETHER THIS LOW WILL TRAVEL OFFSHORE OR UP THE COAST
BUT OVER LAND. AHEAD OF THE SYSTEM SUNDAY MAY REQUIRE SMALL CRAFT
ADVISORY TO DUE 6 FT SEAS. NORTHWEST TO WESTERLY WINDS WILL BE FOUND
BEHIND THE STORM FROM MONDAY AND BEYOND. WINDS AND SEAS WILL QUICKLY
SETTLE ON MONDAY AND REMAIN IN THE 2 TO 3 FT RANGE IN THE OFFSHORE
FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 9 AM EST FRIDAY FOR SCZ017-023-024-
032>034-039-046.
NC...DENSE FOG ADVISORY UNTIL 9 AM EST FRIDAY FOR NCZ087-096-097-
099>101.
MARINE...NONE.
&&
$$
SYNOPSIS...DCH/SHK
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...HDL
000
FXUS62 KRAH 200227
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
930 PM EST THU NOV 19 2009
.SYNOPSIS...
A COLD FRONT OVER WESTERN NC WILL PUSH EAST OVERNIGHT.
HIGH PRESSURE WILL THEN EXPAND INTO THE REGION THROUGH SATURDAY...
IN ADVANCE OF THE NEXT STORM SYSTEM EXPECTED TO ARRIVE ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM THURSDAY...
...DENSE FOG ADVISORY FOR ALL OF CENTRAL NC TONIGHT...
BROKEN LINE OF SHOWERS MOVING EAST INTO COASTAL SECTIONS OF THE
STATE IS ASSOCIATED WITH THE MERGED WEDGE FRONT/COASTAL TROUGH
BOUNDARY. ONLY ONE STORM BRIEFLY EXHIBITED SOME WEAK ROTATION (NEAR
THE DURHAM/WAKE COUNTY LINE)AS IT TRACKED ALONG THE WEDGE TMB...BUT
INSUFFICIENT INSTABILITY PREVENTED ANY ORGANIZED/SUSTAINED COUPLET
FROM HOLDING TOGETHER AS MLCAPES WERE 250 JOULES OR LESS ACROSS THE
CENTRAL PIEDMONT. THE BROKEN CONVECTIVE LINE ASSOCIATED WITH MERGED
WEDGE FRONT IS CURRENTLY PUSHING INTO A SLIGHTLY MORE FAVORABLE
ENVIRONMENT WITH MLCAPES AROUND 500 JOULES...SO WILL CONTINUE TO
MONITOR RADAR FOR THE POTENTIAL FOR ANY BRIEF SPIN UPS AS LCLS
REMAIN LOW AOA 500 M.
ONCE THIS LINE PUSHES EAST OF THE AREA...RAIN CHANCES WILL BE PRETTY
MUCH OVER EVEN WITH THE COLD FRONT PASSAGE PROGGED TO MOVE THROUGH
THE AREA LATER TONIGHT...BETWEEN 06 TO 12Z. THE FORECAST CHALLENGE
THEN TURNS TOWARDS THE DURATION AND EXTENT OF DENSE FOG...AS WE ARE
ALREADY SEEING DENSE FOG DEVELOP ACROSS THE FOOTHILLS AND WESTERN
PIEDMONT...EAST OF THE COLD FRONT WHERE CLEARING HAS TAKEN PLACE.
CURRENT THINKING IS THAT DUE TO THE TARDINESS OF THE FROPA AND
ACCOMPANYING DRY AIR ADVECTION...DENSE FOG WILL BE WIDESPREAD ACROSS
THE EASTERN TWO-THIRDS OF THE FORECAST AREA...FROM THE TRIANGLE EAST.
TOUGHER CALL ACROSS THE WESTERN PIEDMONT WHERE THE EARLIER ARRIVAL
OF THE FROPA BETWEEN 06 TO 09Z WILL CERTAINLY IMPROVE/DISSIPATE
THE FOG.
WILL GO AHEAD AND ISSUE A DENSE FOG ADVISORY (DFA) FOR ALL OF
CENTRAL NC OVERNIGHT...SEGMENTING THE ADVISORY TO ACCOUNT FOR THE
TIMING OF THE FROPA AND IMPROVING CONDITIONS FROM WEST TO EAST
ACROSS THE AREA. THE DFA WILL END AT 6 AM EST FOR THE WESTERN
PIEDMONT INCLUDING THE TRIAD. WILL DELAY THE START TIME FOR THE
DFA FOR CENTRAL AND EASTERN SECTIONS UNTIL MIDNIGHT...AND ENDING AT
9 AM EST.
A WIDE RANGE IN OVERNIGHT LOWS TONIGHT DUE TO THE TIMING OF THE
FROPA...LOWS IN THE MID 40S NW TO MID/UPPER 50S EAST.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
AS OF 250 PM THURSDAY...
FOR FRIDAY THROUGH SATURDAY: THE COLD FRONT SHOULD BE SHIFTING OFF
THE COAST BY FRIDAY MORNING. WITH RATHER LIGHT SURFACE WINDS BEHIND
THE FRONT AND PLENTY OF RESIDUAL NEAR-SURFACE MOISTURE... EXPECT
PATCHES OF FOG TO PERSIST PAST DAYBREAK. OTHERWISE... EXPECT A BRIEF
PERIOD OF QUIET WEATHER HEADING INTO SATURDAY. THE SURFACE HIGH
DRIFTS NORTH-NORTHEAST THROUGH THE OH VALLEY FRIDAY AS IT BEGINS TO
BUILD INTO NC. WITH A MAINLY FLAT SOUTHWEST MID LEVEL FLOW OVER THE
INTERIOR SOUTHEAST... FORECAST SOUNDINGS SHOW STABLE SUBSIDING AIR
ALOFT AND A DRY COLUMN. MODEL FORECAST LOW LEVEL THICKNESSES ARE
JUST SLIGHTLY ABOVE NORMAL... AND FACTORING IN PLENTY OF SUNSHINE
ALONG WITH UPSTREAM TEMPS AND THE MILD NATURE OF THE INCOMING AIR
MASS... EXPECT HIGHS OF 62-68. THE HIGH CENTER MOVES OVER WV FRIDAY
NIGHT AND CONTINUES RIDGING INTO NC... CAUSING SURFACE WINDS TO VEER
AROUND TO NORTH-NORTHEAST AND PULL IN COOLER AIR. FORECAST SOUNDINGS
SHOW SOME INCREASE IN HIGH CLOUDS OVERNIGHT AHEAD OF THE NEXT STORM
SYSTEM PUSHING INTO THE SOUTHERN PLAINS/WEST GULF REGION... HOWEVER
THESE APPEAR TO BE THIN ENOUGH TO HAVE MINIMAL IMPACT ON GROUND HEAT
LOSS. NUDGED LOWS DOWN A DEGREE OR SO TO 37-44. MID-UPPER LEVEL
MOISTURE STEADILY INCREASES AND DEEPENS SATURDAY AS THE MID LEVEL
VORTEX CROSSES LA INTO MS. THE SURFACE HIGH TO OUR NORTH PASSES
SLOWLY NORTHWARD TO THE OH/PA BORDER AND BECOMES SUPPORTED BY
CONFLUENT FLOW ALOFT WITH NORTHERN STREAM SHORTWAVE TROUGHING OVER
PA... AND THIS SHOULD ENSURE A STEADY FEED OF LOW LEVEL DRY AIR INTO
CENTRAL NC... SETTING US UP FOR DAMMING ONCE THE SURFACE HIGH CAN
GET INTO A MORE FAVORABLE POSITION (OVER THE ST LAWRENCE VALLEY)
SATURDAY NIGHT WHERE IT CAN TAP INTO EVEN COOLER AIR AND STRENGTHEN
FURTHER AND SUPPORT ALOFT PERSISTS. HIGHS SATURDAY 60-65 WITH
INCREASING AND THICKENING CLOUDS.
FOR SATURDAY NIGHT/SUNDAY: MODELS AGREE FAIRLY WELL ON THE MID LEVEL
SHORTWAVE TROUGH DEAMPLIFYING A BIT AS IT LIFTS WITH A NEGATIVE TILT
FROM NORTHEAST LA TO NORTHEAST MS SATURDAY NIGHT... WITH A STEADY
LOWERING OF THE CLOUD BASE OVER NC OVERNIGHT. ISENTROPIC UPGLIDE
COMMENCES OVER SOUTHERN NC LATE... HOWEVER THE LATEST MODEL GUIDANCE
SUGGESTS THAT MOST PRECIP WILL HOLD OFF UNTIL AT LEAST SUNDAY
MORNING. TYPICALLY... WITH ANOMALOUSLY LOW PRESSURE AREAS NEAR THE
GULF COAST REGION SUCH AS THIS... WE SEE SUBSTANTIAL CONVECTION IN
THE WARM SECTOR... FROM THE NORTHEAST GULF NORTHWARD INTO THE
EASTERN GULF STATES/GA... SOUTH OF THE WEDGE WARM FRONT WHICH IS
LIKELY TO EXTEND ACROSS CENTRAL GA AND SOUTHERN SC HEADING INTO
SUNDAY MORNING. GIVEN THAT THE BEST MOISTURE TRANSPORT WILL OCCUR
FROM THE NORTHEAST GULF UP AND OVER THIS WARM FRONT WHERE LOW LEVEL
MASS CONVERGENCE IS MAXIMIZED... AND CONSIDERING THE DRY SUBCLOUD
LAYER NOTED ON FORECAST SOUNDINGS... WE ARE LIKELY TO SEE ONLY VERY
LIGHT RAIN (IF ANYTHING) SATURDAY NIGHT. HAVE TRIMMED BACK POPS TO
LOW CHANCE AND CUT AMOUNTS DOWN TO JUST A FEW HUNDREDTHS THROUGH
DAYBREAK. LOWS 42-47. AS THE MID LEVEL LOW TRACKS UP THROUGH TN INTO
KY SUNDAY (A FARTHER-WEST TRACK THAN WHAT WAS SEEN ON YESTERDAY`S
MODELS)... EXPECT A MILLER TYPE B PATTERN TO DEVELOP WITH THE
PRIMARY LOW WELL WEST OF THE SOUTHERN APPALACHIANS AND SECONDARY LOW
PRESSURE DEVELOPING OFF THE CAROLINA COAST. ALONG WITH THE QUICKLY
SATURATING COLUMN (PRECIP WATER RISING TO 250% OF NORMAL)... FORCING
FOR ASCENT IMPROVES WITH DEEPENING AND STRENGTHENING ISENTROPIC
UPGLIDE... MID LEVEL HEIGHT FALLS... AND INCREASED OVERRUNNING WITH
30-35 KTS OF SOUTHERLY FLOW ATOP THE COOL DOME ASSOCIATED WITH THE
APPROACH FROM THE SOUTH OF THE 850 MB WARM FRONT. WILL HOLD ONTO
LIKELY POPS FOR SUNDAY. HOWEVER... WHILE THE DEEP SATURATION AND
FORCING MAKE LIGHT RAIN LIKELY... AMOUNTS ARE PROBLEMATIC TO
DETERMINE. UPPER DIVERGENCE IN THE LEFT EXIT REGION OF THE
SUBTROPICAL JET IS DECENT... BUT THE GREATEST DPVA HOLDS TO OUR
WEST. THE LATEST NAM SHOWS DRIER AIR ABOVE 0C AS COMPARED TO THE
GFS... AND IT FOCUSES MOST OF THE PRECIP AWAY FROM THE WEDGE... WELL
TO OUR WEST OVER THE MOUNTAINS AND OVER THE GULF STREAM. THE SREF
MEAN IS ALSO HINTING AT LESSER AMOUNTS WITH FAIRLY LOW PROBABILITY
OF MORE THAN 0.05" OF RAIN THROUGH EARLY SUNDAY EVENING... HOWEVER
THE GEFS MEAN HAS TRENDED WETTER. WILL KEEP TOTAL AMOUNTS AROUND A
QUARTER TO THIRD INCH FOR NOW. WITH CHILLY NORTHEAST WINDS AND NO
MECHANISMS TO DISLODGE THE COOL STABLE SURFACE BASED LAYER...
PIEDMONT TEMPS MAY STRUGGLE TO RISE... AND HAVE HELD CLOSE TO THE
EARLIER FORECAST... WITH HIGHS 48 TO 57. -GIH
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 255 PM THURSDAY...
FOR SUNDAY NIGHT: THE PRIMARY SURFACE LOW TO OUR WEST IS EXPECTED TO
HEAD INTO THE OHIO VALLEY AND WEAKEN WHILE THE SECONDARY LOW TREKS
UP INTO EASTERN NC. WE DRY OUT ABOVE THE FREEZING LEVEL AS THE MID
LEVEL DRY SLOT NOSES IN FROM THE SOUTHWEST... LEAVING A BRISK
NORTHEAST LOW LEVEL FLOW AND ABUNDANT MOISTURE IN THE LOWEST 2 KM.
WILL KEEP LIKELY POPS THROUGH THE EVENING... THEN WE SHOULD SEE
LIGHT RAIN START TO TREND DOWN TO MOSTLY DRIZZLE AND JUST PATCHY
LIGHT RAIN SOUTHWEST TO NORTHEAST OVERNIGHT. LOWS 45-54 WITH CLOUDY
SKIES.
FOR MONDAY: BASED ON AN AVERAGE LOW POSITION FROM THE CANADIAN/GFS/
ECMWF... THE COASTAL LOW IS LIKELY TO BE OVER THE CENTRAL COASTAL
AREA OF NC MONDAY MORNING... HEADING NORTHEAST ALONG WITH THE AXIS
OF THE SHORTWAVE TROUGH. WILL KEEP HIGH CHANCE POPS AND CLOUDS IN
THE MORNING WITH POPS TAPERING OFF IN THE AFTERNOON. WITH CLOUDS
HOLDING ON LONGER THAN EXPECTED... HAVE CUT BACK HIGHS TO 58-63.
FOR MONDAY NIGHT THROUGH THURSDAY: THE DETAILS OF THE MID-WEEK
FORECAST REMAIN MUDDIED BY DISAGREEMENT AMONG THE MODELS. THE
LONGWAVE PATTERN INDICATED BY THE GFS/ECMWF/CANADIAN TRENDS TOWARD
DEEP TROUGHING DEVELOPING OVER THE MISS VALLEY AND INTERIOR EASTERN
STATES BY THURSDAY. THERE MAY BE A RESIDUAL BAROCLINIC ZONE NEAR OR
JUST OFF THE SOUTHEAST COAST... BUT OVERALL THE OPPORTUNITY FOR ANY
SIGNIFICANT MOISTURE INTO NC APPEARS TO BE LACKING AS WEAK HIGH
PRESSURE BUILDS INTO AND OVER THE AREA FROM THE WEST. WILL KEEP THE
FORECAST MAINLY DRY THROUGH THURSDAY. LOW LEVEL THICKNESSES HOLD
NEAR TO JUST ABOVE NORMAL... THUS WILL HAVE TEMPERATURES FOLLOWING
SUIT WITH HIGHS MOSTLY AROUND 60 TO THE LOWER 60S. -GIH
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 640 PM THURSDAY...
A BROKEN LINE OF SHOWERS AND EVEN AN ISOLATED THUNDERSTORM WILL
CONTINUE TO MOVE EAST ACROSS CENTRAL NORTH CAROLINA AS A WEAK COLD
FRONT PUSHES THROUGH THE REGION. THE LINE HAS MOVED THROUGH ALL
TERMINAL SITES EXCEPT KRWI...WHERE VCSH WAS INCLUDED IN THE TAF FOR
THE NEXT COUPLE OF HOURS. AS PARTIAL CLEARING AND A SLACKENING OF
THE PRESSURE GRADIENT OCCURS BEHIND THE FRONT LATER THIS
EVENING...FOG AND LIFR CEILINGS ARE EXPECTED TO REDEVELOP IN THE
RESIDUALLY MOIST NEAR SURFACE AIR ACROSS CENTRAL NC TONIGHT. DRIER
AIR ASSOCIATED WITH HIGH PRESSURE EXPECTED TO BUILD INTO THE REGION
FROM THE WEST OVERNIGHT MAY DISSIPATE THE FOG FROM WEST TO EAST
LATER TONIGHT. ANY REMAINING FOG (MOST LIKELY AT EASTERN TERMINALS)
SHOULD QUICKLY BURN OFF AFTER SUNRISE FRIDAY... WITH VFR CONDITIONS
AND AN OCCASIONALLY GUSTY (INTO THE MID TEENS KTS) NORTH TO
NORTHWEST WIND THROUGHOUT THE DAY.
ANOTHER STORM SYSTEM COULD RESULT IN MVFR/IFR CONDITIONS SUNDAY
AND/OR SUNDAY NIGHT. VFR CONDITIONS OTHERWISE EXPECTED THROUGH EARLY
NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM EST FRIDAY FOR NCZ007>011-
023>028-040>043-075>078-085-086-088-089.
DENSE FOG ADVISORY UNTIL 6 AM EST FRIDAY FOR NCZ021-022-038-
039-073-074-083-084.
&&
$$
SYNOPSIS...CBL
NEAR TERM...CBL
SHORT TERM...HARTFIELD
LONG TERM...HARTFIELD
AVIATION...KRR/MWS
000
FXUS62 KMHX 200217
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
917 PM EST THU NOV 19 2009
.SYNOPSIS...
A WEAK TROUGH OF LOW PRESSURE WILL GRADUALLY DISSIPATE TONIGHT AS
HIGH PRESSURE BUILDS IN FROM THE NORTH AND WEST FRIDAY INTO
SATURDAY. LOW PRESSURE WILL MOVE NORTH FROM THE GULF OF MEXICO
SUNDAY AND NORTH OF THE AREA BY MONDAY. HIGH PRESSURE WILL REBUILD
OVER THE AREA TUESDAY THROUGH LATE NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 910 PM THURSDAY...LINGERING SHOWERS ACROSS THE AREA. THINK
THAT SHOWERS INLAND WILL BEGIN TO SLOWLY DISSIPATE OVER THE NEXT
FEW HOURS WITH BETTER CHANCE REMAINING ALONG THE COAST...STILL
SOME INSTABILITY ACROSS THE AREA SO COULD CONTINUE TO SEE ISOLATED
THUNDERSTORMS AS WELL. HAVE ISSUED DENSE FOG ADVISORY TONIGHT.
VISIBILITIES ALREADY BEGINNING TO SLOWLY DROP AND EXPECT THAT TO
CONTINUE OVERNIGHT. VSBYS SHOULD BEGIN TO LIFT WITH SUNRISE FRIDAY
MORNING. LOWS IN THE MID/UPPER 50S.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 235 PM THURSDAY...HIGH PRESSURE SHOULD BUILD OVER THE REGION
FOR FRIDAY AND FRIDAY NIGHT. EXPECT A GOOD DEAL OF SUNSHINE FRIDAY
WITH SUN OVERCOMING WEAK CAA ALLOWING MAX TEMPS INTO THE MIDDLE
AND UPPER 60S. WITH CLEAR SKIES AND RELATIVELY LIGHT WINDS...FRIDAY
NIGHT SHOULD BE CHILLY WITH MINS IN MOST AREAS DROPPING INTO THE
40S.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 1130 AM THURSDAY...HIGH PRESSURE WILL RIDGE INTO THE REGION
FROM THE NORTH AND WEST ON SATURDAY WITH PRECIP REMAINING TO THE
SOUTH. STILL DIFFERENCES BETWEEN GFS AND THE ECMWF/HPC GUIDANCE
WITH REGARDS TO TRACK OF LOW PRES ON SUNDAY. GFS SHOWING A MORE
INLAND TRACK WHILE THE ECMWF SOLUTION AND HPC GRAPHICS INDICATING
A SYSTEM OFFSHORE. INSTEAD OF A POWERFUL LOW AS WE SAW LAST
WEEKEND...ANTICIPATE MORE OF A SERIES OF WAVES OF LOW PRESSURE
ALONG FRONTAL BOUNDARY OFFSHORE. REGARDLESS OF SOLUTION...BOTTOM
LINE IS ANOTHER ROUND OF PSBL HEAVY RAINFALL ON SUNDAY WITH HPC
QPF GUIDANCE INDICATING 1 TO 3 INCHES...WITH FOCUS ON SOUTH
COAST...WHERE SOME AREAS HAVE RECEIVED UP TO 15 INCHES OVER THE
PAST WEEK OR SO...WHICH WILL AGGRAVATE AN ALREADY HIGH WATER
TABLE. WILL HAVE LIKELY POPS ON SUNDAY AND HIGH CHC SUNDAY
NIGHT...TAPERING TO SLIGHT CHC MONDAY AS LOW EXITS TO THE
NORTHEAST. TEMPS THROUGH THE WEEKEND WILL BE NEAR OR A LITTLE
ABOVE NORMAL LEVELS. FOR TUESDAY INTO THANKSGIVING...HIGH PRES
BUILDS IN FROM THE WEST WITH EARLY INDICATIONS OF SOME RATHER
CHILLY AIR TOWARD THE END OF NEXT WEEK.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
AS OF 900 PM THURSDAY...THE WEAK FRONT IS CURRENTLY OVER CENTRAL
NC WITH A FEW ISOLATED HEAVY SHOWERS OCCURRING ALONG IT AS WELL AS
NEAR THE COAST. THERE WILL BE A SMALL RISK OF AN ISOLATED SHOWER
AT THE TAF SITES THROUGH 09Z BY WHICH TIME THE FRONT SHOULD BE
EAST OF THE SITES. OF GREATER CONCERN IS THE POTENTIAL FOR
WIDESPREAD DENSE FOG OVERNIGHT. ALL OF THE AVIATION GUIDANCE IS IN
EXCELLENT AGREEMENT ON THIS. THE UPS FOG TOOL ALSO WAS INDICATING
A POTENTIAL FOR DENSE FOG. THE FOG SHOULD BEGIN EARLY TOO AS
TEMP/DEWPOINT DEPRESSIONS WERE VERY LOW THIS EVENING. LIMITING
FACTOR INITIALLY WILL BE THE PATCHY LOW CLOUDS OCCURRING AHEAD OF
THE FRONT BUT WHERE BREAKS IN THE CLOUDS HAVE OCCURRED VISIBILITIES
HAVE DROPPED TO IFR. THE FOG COULD END A LITTLE EARLIER THAN USUAL
FRIDAY MORNING AS THE NAM-12 IS INDICATING SURFACE WINDS AROUND 10
AROUND 12Z.
VFR CONDITIONS EXPECTED FRI INTO EARLY SUN. A COASTAL LOW WILL
LIKELY BRING REDUCED CIGS SUN AFTERNOON INTO EARLY MON.
&&
.MARINE...
AS OF 900 PM THURSDAY...WINDS HAVE DIMINISHED TO 10 KT OR LESS
EXCEPT FOR THE OUTER WATERS WHERE THEY WERE STILL BLOWING AROUND
15 KT. SEAS WERE STILL IN THE 5-7 FT CENTRAL/NORTH AND 4-6 FT
SOUTH RANGE THOUGH SO NO CHANGES TO CURRENT ADVISORIES. THE FRONT
SHOULD BE THROUGH THE SOUTHERN WATERS AROUND 09Z AND THE
CENTRAL/NORTHERN WATERS AROUND 12Z. LIGHT SOUTHERLY FLOW WILL
BRIEFLY SURGE TO NORTH AROUND 20 KT NORTHERN/CENTRAL WATERS FRIDAY
MORNING AND AROUND 15 KT SOUTH. OFFSHORE FLOW IN THE WAKE OF THE COLD
FRONT WILL HELP TO REDUCE SEAS A BIT MORE FRI THROUGH SAT AHEAD OF
A COASTAL LOW AND EXPECT A PERIOD OF SUB SCA CONDITIONS SAT NIGHT
AND EARLY SUN. MODELS CONTINUE TO WAVER ON THE TRACK OF THE LOW
WITH THE NEXT SYSTEM AND WILL MAINTAIN CONTINUITY IN TRACKING THE
LOW OFFSHORE SUN/SUN NIGHT. A PERIOD OF SCA CONDITIONS LIKELY
ACROSS MOST OF THE WATERS LATE IN THE WEEKEND AND EARLY NEXT WEEK
ASSOC WITH THE LOW.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...DENSE FOG ADVISORY UNTIL 9 AM EST FRIDAY FOR NCZ029-044>047-
079>081-090>095-098.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST SATURDAY NIGHT FOR
AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR AMZ156.
SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR AMZ150.
SMALL CRAFT ADVISORY UNTIL 5 AM EST FRIDAY FOR AMZ158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CQD
SHORT TERM...CTC
LONG TERM...CTC
AVIATION...JME/SK
MARINE...JME/SK
000
FXUS62 KILM 192313
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
615 PM EST THU NOV 19 2009
.SYNOPSIS...
WEAK LOW PRESSURE WILL DISSIPATE TONIGHT AS HIGH PRESSURE BUILDS
IN FROM THE WEST. THIS HIGH WILL PREVAIL UNTIL ANOTHER STORM
SYSTEM IMPACTS THE AREA LATE SATURDAY INTO EARLY MONDAY FOLLOWED
BY HIGH PRESSURE ONCE AGAIN.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2:30 PM THURSDAY...ISOLATED LIGHT SHOWERS MOVING FROM SOUTH TO
NORTH OVER OUR NORTH CAROLINA COUNTIES THIS AFTERNOON. THESE ARE
SHOWING NO SIGN OF INTENSIFYING INTO SOMETHING MORE SIGNIFICANT AND
THIS MAKES SENSE GIVEN VERY DRY AIR MOVING IN ALOFT AND STRONG
INVERSION AT AROUND 850MB. MODEL SOUNDINGS AND TIME HEIGHT CROSS
SECTIONS SHOW VERY DRY AIR CONTINUING TO MOVE IN AT GRADUALLY LOWER
LEVELS SO AS TIME PROGRESSES OVER THE NEAR TERM OUR CHANCES FOR
PRECIP WILL DIMINISH ACCORDINGLY. ALREADY HAVE ONLY SLIGHT CHANCE
FOR SHOWERS FOR THE REMAINDER OF THIS AFTERNOON AND EVENING AND DRY
OVERNIGHT. WITH HIGH DEWPOINTS EXPECT ANOTHER NIGHT OF ABOVE
AVERAGE...MILD TEMPERATURES. HOWEVER...WITH LIGHT WINDS AND
CLEARING SKIES AND STILL MOIST LOWEST LEVELS THINK WE WILL SEE SOME
FOG FORMATION...AT LEAST PATCHY AND PERHAPS AREAS OF FOG OVERNIGHT.
OVERNIGHT TEMPS RANGE FROM AROUND 50 INLAND TO 55 AT THE COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2:30 PM THURSDAY...SPLIT FLOW AT THE MID LEVELS WILL BRING A STORM
SYSTEM ACROSS THE AREA LATE IN THE PERIOD WHICH WILL BE THE FOCUS
OF THIS FORECAST. IS APPEARS THE TIMING HAS BEEN DELAYED EVER SO
SLIGHTLY IN BOTH THE GFS AND NAM ALTHOUGH THE NAM IS GENERATING A
STRONGER LOW ALONG AN OLD FRONTAL BOUNDARY THAT WILL RESIDE
OFFSHORE WHILE THE GFS IS MORE RESERVED. OVERALL HAVE BACKED OFF
ON POPS FOR SATURDAY AFTERNOON AND EVENING. SHOULD SEE MORE SUN
SATURDAY AS WELL AND HAVE ADJUSTED MAX TEMPERATURES UP SLIGHTLY.
AS FOR FRIDAY...SHOULD SEE A MOSTLY SUNNY DAY WITH HIGH
TEMPERATURES AROUND 70 TO THE LOWER 70S IN GEORGETOWN AND
WILLIAMSBURG COUNTIES.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 2:30 PM THURSDAY...SOUTHERN BRANCH STORM SYSTEM WITH GOOD GULF OF
MEXICO MOISTURE CONNECTION WILL AFFECT THE AREA SUNDAY INTO SUNDAY
NIGHT. INITIAL SURFACE WAVE WILL APPROACH FROM THE CENTRAL GULF
COAST AND OVERRUN THE SURFACE WEDGE IN PLACE. SUNDAY NIGHT HAS THE
STORM JUMP THE WEDGE AND DEVELOP A SECONDARY LOW OFF THE CAROLINA
COAST. 850MB MAY MAX OUT AS HIGH AS 45 KT LEADING TO STRONG
ISENTROPIC UPGLIDE AND A GOOD HALF INCH TO INCH OF RAINFALL STILL
APPEARS TO BE A GOOD AREAL AVERAGE FORECAST. DRY AIR WILL WRAP IN
BEHIND THE LOW ON MONDAY ALTHOUGH THE DAY MAY START OUT WITH CLOUDS
AND DRIZZLE. LOW AMPLITUDE ALOFT AND NO REAL COLD ADVECTION SO
MONDAY PM SHOULD END UP MUCH MILDER THAN SUNDAYS COOL READINGS. THE
MIDWEEK PERIOD OF TUESDAY AND WEDNESDAY WILL BRING WEAK HIGH
PRESSURE BUILDING IN FROM THE NORTH. THE NORTHERN BRANCH WILL HAVE
SOME FAIRLY STRONG AND PROGRESSIVE TROUGHS BUT THEY WILL BYPASS THE
FORECAST AREA FAR ENOUGH TO THE NORTH TO PREVENT BRINGING ANY
WEATHER. TEMPS SHOULD BE FAIRLY SEASONABLE. A LITTLE PHASING IN OF
THE POLAR JET COULD DRIVE A COLD FRONT ACROSS THE AREA BY THURSDAY
BRINGING IN SOME CHILLY WEATHER. THE BOUNDARY ITSELF WILL BE
MOISTURE-STARVED AND WILL LIKELY NOT BRING RAIN CHANCES.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
SHOWERS OVER PORTIONS OF THE CWA WILL DISSIPATE EARLY IN THE
FORECAST PERIOD AS A TROUGH ROTATES NORTHEAST AND THE SURFACE BEGINS
TO RADIATE. GOOD LOW LEVEL MOISTURE AND LIGHT WINDS WILL SUPPORT
POSSIBLE HEAVY FOG AND LOW STRATUS AFTER MIDNIGHT. ATMOSPHERE DRIES
OUT SIGNIFICANTLY BY MID MORNING FRIDAY...WITH VFR CONDITIONS
EXPECTED. WINDS WILL BECOME NORTH NORTHEAST FRIDAY AS HIGH PRESSURE
BUILDS IN.
EXTENDED OUTLOOK...VFR FRIDAY/SATURDAY. SHOWERS AND LOW CEILINGS
MOVE BACK IN SATURDAY NIGHT THROUGH MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2:30 PM THURSDAY...AT THE SURFACE WE HAVE A WEAK LOW PRESSURE
CENTER AND ASSOCIATED FRONTAL SYSTEM MOVING NORTHEAST ACROSS THE
WATERS. SYSTEM WILL BE PUSHED WELL OUT OF THE AREA OVERNIGHT BY HIGH
PRESSURE BUILDING IN FROM THE NW. CURRENT SEAS OF AROUND 5 FT WILL
CONTINUE TO VERY GRADUALLY SUBSIDE THIS AFTERNOON AND EVENING UNTIL
THEY ARE AROUND 2 TO 4 FT BY DAYBREAK FRIDAY. WINDS A BIT ON THE
VARIABLE SIDE WITH LOW MOVING ACROSS THE WATERS BUT THEY WILL TURN
OFFSHORE THIS EVENING...PICKING UP TO AROUND 10 TO 15 KTS FROM THE
NW BY THE END OF THE NEAR TERM.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 2:30 PM THURSDAY...HIGH PRESSURE MOVING ACROSS THE MIDWEST WILL BE
THE DOMINANT WEATHER FEATURE THROUGH THE SHORT TERM. INITIALLY WINDS
WILL BE FROM THE NORTHWEST AROUND 15 KNOTS. THE DIRECTION WILL VEER
TO MORE OF A NORTHEASTERLY DIRECTION BY SATURDAY MORNING. A NE FLOW
WILL PREVAIL AND INTENSIFY A BIT AS LOW PRESSURE DEVELOPS OVER THE
LOWER MISSISSIPPI VALLEY AND THE HIGH BEGRUDGINGLY HOLDS ON.
SEAS...ESPECIALLY ACROSS THE OUTER WATERS...MAY OCCASIONALLY REACH
SCEC CRITERIA WITH THE PROLONGED FETCH. CLOSER TO SHORE...A MORE
MANAGEABLE 2-3 FEET WILL PREVAIL.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 2:30 PM THURSDAY...SUNDAY SHOULD BRING THE MOST INCLEMENT WEATHER
OF THE LONG TERM PD. A STORM SYSTEM MOVING OUT OF THE GULF OF MEXICO
WILL PINCH THE GRADIENT AS SURFACE HIGH TO THE NORTH HANGS ON.
SUNDAY NIGHT A WEAKER SECONDARY LOW SHOULD FORM OFF THE COAST AND
MOVE TO THE NORTHEAST. THIS IS COMPLICATING THE FORECAST AS IT IS
UNCERTAIN WHETHER THIS LOW WILL TRAVEL OFFSHORE OR UP THE COAST BUT
OVER LAND. AHEAD OF THE SYSTEM SUNDAY MAY REQUIRE SMALL CRAFT
ADVISORY TO DUE 6 FT SEAS. NORTHWEST TO WESTERLY WINDS WILL BE FOUND
BEHIND THE STORM FROM MONDAY AND BEYOND. WINDS AND SEAS WILL QUICKLY
SETTLE ON MONDAY AND REMAIN IN THE 2 TO 3 FT RANGE IN THE OFFSHORE
FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...REK
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...43
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