[top]
000
FXUS61 KLWX 241946
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
246 PM EST TUE NOV 24 2009
.SYNOPSIS...
MOIST ONSHORE FLOW WILL CONTINUE AS HIGH PRESSURE BUILDS ACROSS NEW
ENGLAND. AN AREA OF LOW PRESSURE WILL FORM NEAR THE GULF COAST
WEDNESDAY...AND MOVE UP THE EASTERN SEABOARD THROUGH THE END OF THE
WEEK. MEANWHILE...A COLD FRONT WILL PASS THROUGH THE AREA ON
THANKSGIVING. HIGH PRESSURE RETURNS FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL REMAIN ACROSS EASTERN CANADA AND NEW ENGLAND
TONIGHT...WITH A NORTH LOW LEVEL WIND TURNING MORE TO THE NORTHEAST
OR EAST OVERNIGHT. LOW LEVEL MOISTURE WILL REMAIN IN PLACE...AND
WILL KEEP THE LOW DECK OF CLOUDS ACROSS THE CWA.
AREAS OF LIGHT RAIN/DRIZZLE WILL CONTINUE NEAR THE BAY LATE THIS
AFTERNOON...THEN DRIZZLE WILL EXPAND WESTWARD. IN ADDITION...SREFS
ALSO INDICATE RELATIVELY HIGH POPS FOR LIGHT AMOUNTS OF MEASURABLE
RAIN TOO...SO HAVE INCREASED CHANCES FOR MEASURABLE RAIN ESPECIALLY
EAST OF THE MTNS WHERE A FEW HUNDREDTHS OF AN INCH OF RAINFALL MAY
RESULT.
ANOTHER ASPECT TO CONSIDER WILL BE THE FOG...WHICH SOME GUIDANCE
SUGGESTS MAY DROP TO 1/4 TO 1/2SM LEVELS. AM NOT GOING THIS
AGGRESSIVE AND THUS NO DENSE FOG ADVISORY WILL BE ISSUED ATTM.
HOWEVER...WILL MENTION PROSPECT FOR FOG WITH VSBYS TO 1SM...AND
EVENING SHIFT CAN GO MORE PESSIMISTIC IF NECESSARY.
TEMPERATURES WILL LOWER ONLY A LITTLE OVERNIGHT...MOST LIKELY IN THE
MID TO UPPER 40S.
&&
.SHORT TERM /WEDNESDAY/...
DO NOT ENVISION THE ATMOSPHERE CHANGING MUCH ON WEDNESDAY. FAVOR THE
IDEA THAT THE LOW LEVELS REMAIN MOIST...KEEPING THE LOW DECK OF
CLOUDS IN PLACE. HAVE ALSO CONTINUED THE IDEA OF HIGHER CHANCES OF
MEASURABLE RAIN ACROSS THE CWA THAN WHAT MOS INDICATES.
RAIN/DRIZZLE/FOG ALL SEEM LIKE A GOOD BET ON WEDNESDAY ESPECIALLY
EAST OF THE MTNS AS LOW LEVEL FLOW TURNS MORE TOWARD THE SOUTHEAST
BY AFTERNOON. CIGS MAY START TO INCREASE/BREAK ACROSS NORTH CENTRAL
VIRGINIA IF FLOW WINDS UP GOING MORE SOUTH. OVERALL...THE DIURNAL
TEMPERATURE CURVE WILL ALSO BE SMALL GIVEN THESE CONDITIONS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
SKIES EXPECTED TO REMAIN CLOUDY TOMORROW NIGHT AHEAD OF A COLD
FRONT. THIS TIME OF YEAR...IT IS NOT UNCOMMON FOR THE LOW
CLOUDS/DRIZZLE TO CONTINUE UNTIL A FRONT COMES THROUGH. THE FRONT IS
EXPECTED TO MOVE THROUGH ON THANKSGIVING...BRINGING A CHANCE OF
SHOWERS DURING THE DAY AND INTO THE EVENING. COLDER AIR IS EXPECTED
TO SETTLE OVER THE REGION BEHIND THE FRONT. COLD HIGH PRESSURE WILL
CONTINUE THROUGH THE REMAINDER OF THE WEEKEND...WITH ANOTHER FRONTAL
SYSTEM EXPECTED FOR THE FIRST OF NEXT WEEK.
MODELS ARE PROGGING A COASTAL LOW TO EMERGE OFF THE SE GA/NE FL
COAST WEDNESDAY NIGHT AND MOVE UP THE MID ATLANTIC COAST THURSDAY
INTO FRIDAY. NW WINDS ON THE BACKSIDE OF THE FRONT/COASTAL LOW WILL
TRANSPORT MOISTURE SE FROM THE GREAT LAKES...WITH UPSLOPE SNOW
SHOWERS EXPECTED ACROSS THE WESTERN SLOPES OF THE ALLEGHENIES. SNOW
SHOWERS WILL LAST WELL INTO FRIDAY...WITH A SEVERAL INCHES POSSIBLE.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
KCHO HAS IMPROVED TO VFR THIS AFTERNOON...WHILE THE HUBS HAVE
CONTINUED IFR CIGS AND MVFR-IFR VSBYS /MAINLY IFR IN RA/DZ/. KCHO
WILL BE BACK ON THE DECLINE LATE TODAY/EARLY THIS EVENING...JOINING
THE IFR CONDITIONS AT THE OTHER TERMINALS. LIFR CIGS ACTUALLY LOOK
LIKELY OVERNIGHT INTO WEDNESDAY MORNING. SOME GUIDANCE ALSO SUGGESTS
THAT VSBYS MAY DETERIORATE TO LIFR AS WELL. MINOR IMPROVEMENT MAY
OCCUR DURING THE DAYTIME WEDNESDAY...BUT AM LEANING TOWARD IFR
CONDITIONS CONTINUING EXCEPT MAYBE KCHO LATE IN THE DAY.
SUB VFR CIGS/VSBYS WILL BE LIKELY UNTIL A FRONT MOVES THROUGH THE
AREA ON THANKSGIVING. HIGH PRESSURE WILL BUILD ACROSS THE AREA FOR
FRIDAY INTO THE WEEKEND...WITH NO CIG/VSBY RESTRICTIONS ANTICIPATED.
&&
.MARINE...
NORTHERLY WINDS LATE TODAY WILL TURN BACK TOWARD THE NORTHEAST AND
THEN EAST OVERNIGHT TONIGHT...THEN TO THE SOUTHEAST ON WEDNESDAY.
SPEEDS ARE FORECAST TO REMAIN AROUND OR JUST BELOW 10 KT THROUGH THE
PERIOD. RAIN/DRIZZLE WILL REDUCE VSBYS TO 1 NM OR LESS AT
TIMES...ESPECIALLY OVERNIGHT INTO WEDNESDAY.
SMALL CRAFT CONDITIONS ARE POSSIBLE THURSDAY NIGHT INTO SATURDAY
BEHIND A COLD FRONT AND AS A COASTAL LOW PRESSURE MOVES UP THE
EASTERN SEABOARD.
&&
.TIDAL/COASTAL FLOOD...
WATER LEVELS WERE RUNNING A FOOT TO FOOT AND A HALF ABOVE NORMAL
THIS AFTERNOON. FORTUNATELY...THE ASTRONOMICAL TIDE IS NOT EXTREMELY
HIGH TODAY INTO WEDNESDAY...AND EVEN THESE ANOMALIES WILL LIKELY BE
UNDER MINOR TIDAL FLOODING THRESHOLDS. THIS IS SUPPORTED BY THE MDL
EXTRATROPICAL MODEL AND CBOFS. THEREFORE...NOT EXPECTING TO ISSUE A
COASTAL FLOOD ADVISORY AT THIS TIME.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
PELOQUIN/LISTEMAA
000
FXUS61 KLWX 241450
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
950 AM EST TUE NOV 24 2009
.SYNOPSIS...
ONE AREA OF LOW PRESSURE WILL MOVE NORTHEAST AWAY FROM THE REGION
THIS AFTERNOON. WEAK HIGH PRESSURE BUILDS OVER THE MID ATLANTIC
TONIGHT. ANOTHER AREA OF LOW PRESSURE WILL FORM NEAR THE GULF
COAST WEDNESDAY...AND MOVE UP THE EASTERN SEABOARD THURSDAY.
MEANWHILE...A COLD FRONT WILL PASS THROUGH THE AREA THURSDAY AND
THURSDAY NIGHT. HIGH PRESSURE RETURNS FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
12Z KI AD RAOB TELLS THE TALE THIS MORNING...WITH LOTS OF MOISTURE
LINGERING IN THE LOW LEVELS OF THE ATMOSPHERE. NORTH/NORTHEAST
LOW LEVEL GRADIENT WILL CONTINUE TODAY...KEEPING THE MOISTURE IN
PLACE AND RESULTING IN AN OVERCAST LOW CLOUD COVER. HAVE HAD SOME
RAIN AND DRIZZLE AS WELL...WITH THE MEASURABLE RAIN TRANSLATING
CLOSER TO THE BAY BUT SOME DRIZZLE PERSISTING WEST INTO THE
WASHINGTON METRO AREA.
HAVE STRUCTURED POPS/WX/QPF IN THIS WAY...WITH HIGH POPS FOR
MEASURABLE RAIN CLOSE TO THE BAY FOR THE NEXT FEW HOURS...TAPERING
OFF QUICKLY TO THE WEST BUT MENTIONING DRIZZLE WEST TO THE BLUE
RIDGE.
DIURNAL TEMPERATURE RANGE WILL BE SMALL...MORE THAN LIKELY
HOVERING IN THE UPPER 40S TO LOWER 50S RANGE. REWORKED
TEMP/DEWPOINT GRIDS TO MATCH LATEST OBS AND TRENDS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
TNGT YOU COULD THINK OF IT AS THE MID ATLC WL BE UNDER WK HIGH
PRES OR THAT IT WL BE IN BTWN SYSTEMS. EITHER WAY LO LVL MOISTURE
WL RMN OVR THE CWA BRINGING XTNSV CLD CVR...AND PSBLY PLENTY OF
FOG TNGT. MDLS ARE PREDICTING VSBYS BLO 1NM TNGT...I`M ALWAYS
SKEPTICAL OF REALLY TANKING THE VSBY 24 HRS IN ADVANCE UNLESS
WE`RE GOING TO XPRNC TOP NOTCH RAD CONDS..AND I DON`T THINK THIS
WL NOT BE ONE OF THOSE NGTS. HOWEVER I`LL STILL MENTION FOG/DZ IN
THE GRIDDS OVRNGT AND IF LATER SHIFTS THINK DIFFERENTLY THEY CAN TAKE
VSBYS BLO 1SM FOR TNGT. AGN LTL MVMNT OF TEMPS - RANGE WL BE FM
L40S IN THE HIGHLANDS TO A50 ON THE BAY.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
LEAD SHORTWAVE ENERGY EMBEDDED IN C CONUS H5 TROUGH WILL LIFT NWD
THRU THE GREAT LAKES WED. ISENTROPIC LIFT AIDED BY SLY LLVL FLOW AND
DPVA AHEAD OF SHORTWAVE TROUGH SHOULD PROVIDE ENOUGH FORCING FOR LGT
SHOWERS DURING THE DAY WED.
NEXT UPPER SHORTWAVE ENERGY WILL BE QUICK TO FOLLOW...DIGGING AROUND
BACKSIDE OF SYNOPTIC-SCALE UPPER TROUGH WED/WED NGT. HEIGHT FALLS
AHEAD OF THE UPPER TROUGH WILL LEAD TO COASTAL CYCLOGENESIS JUST OFF
THE SE COAST LATE WED. SFC LOW WILL TRACK NEWD BUT SHOULD TRACK TOO
FAR OFF THE COAST TO HAVE A DIRECT IMPACT TO OUR CWFA. HOWEVER...
AMPLIFYING UPPER LOW AND STRENGTHENING THERMAL GRADIENT WILL PROVIDE
FORCING FOR ASCENT AND PRECIP SHOULD INCREASE IN COVERAGE THU/THU
NGT. 00Z SUITE OF MODELS SLIGHTLY SLOWER THAN PREV RUNS WITH THIS
SYSTEM...AND THEREFORE MAJORITY OF THE SHOWER ACTIVITY MIGHT HOLD
OFF UNTIL THE LATE AFTN/ERY EVNG ON THANKSGIVING. ATMOSPHERE WILL
QUICKLY COOL BEHIND STRONG COLD FROPA THU NGT. THERMAL PROFILES
APPEAR TO BE COLD ENOUGH TO SUPPORT PRECIP CHANGING TO SNOW ACROSS
THE POTOMAC HIGHLANDS LATE THU NGT...AND POSSIBLY A RAIN/SNOW MIX AS
FAR E AS THE BLUE RIDGE.
CUTOFF LOW TRACKING OVER NEW ENGLAND WILL SLOW DOWN FRI AS UPPER
TROUGH ACQUIRES NEGATIVE TILT. BREEZY CONDITIONS EXPECTED FRI AS
STRONG CAA WILL STEEPEN LLVL LAPSE RATES AND ALLOW FOR STRONGER
WINDS ALOFT TO MIX DOWN TO THE SFC. CORE OF COLD AIRMASS WILL BE
OVRHD FRI NGT WITH A LGT RA/SN MIX AS FAR E AS I-95. UPSLOPE FLOW
AROUND THE UPPER LOW MAY LEAD TO AN ACCUMULATING SNOW EVENT ACROSS
THE WRN SLOPES OF THE ALLEGHENY FRONT AND POTOMAC HIGHLANDS THU NGT
LASTING THRU SAT. TOO ERLY TO NAIL DOWN SPECIFIC SNOWFALL
ACCUMULATIONS BUT THERE IS INCREASING CONFIDENCE FOR WINTER-
WEATHER ADVISORY ACCUMULATIONS.
HIPRES BUILDS BACK INTO THE AREA SUN...BEFORE THE NEXT STORM SYSTEM
APPROACHES ERY NEXT WEEK.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
AIRPORTS WERE MOSTLY EXPERIENCING IFR CIGS THIS MORNING...EXCEPT
FOR KCHO WHICH HAS IMPROVED FOR NOW. VSBYS WERE IFR-MVFR DEPENDING
ON WHETHER RA/DZ WAS OCCURRING OR NOT...AGAIN WITH KCHO THE
EXCEPTION WITH A VFR VSBY. EXPECT IFR/LIFR CIGS TO PERSIST THROUGH AT
LEAST THE NEXT 24 HOURS AT THE HUBS...AND KCHO WILL DROP BACK
DOWN TO IFR THIS EVENING. VSBYS WILL BE VARIABLE...MAINLY IFR IN
RA/DZ AND MVFR IN BR. HOWEVER...EXPECT IFR VSBYS TO BECOMING MORE
PREVAILING AT ALL SITES LATER TONIGHT INTO WEDNESDAY MORNING. WILL
ALSO CONSIDER POSSIBILITY OF LIFR VSBYS FOR THE 18Z TAF ISSUANCE.
A STORM SYSTEM WILL APPROACH THE AREA WED WITH SCT SHOWERS AND MVFR
CIGS. A STRONG UPPER LOW WILL QUICKLY FOLLOW THU-THU NGT...BRINGING
MORE CHANCES FOR PRECIP. IN WAKE OF STRONG COLD FROPA THU NGT...SHSN
MAY MIX IN WITH SHRA AT MRB THU NGT. GUSTY WINDS NW WINDS ARE
EXPECTED ACROSS ALL TERMINALS FRI...LASTING INTO SAT.
&&
.MARINE...
WINDS WERE TURNING MORE NORTH FROM NORTHEAST OVER THE WATERS THIS
MORNING...BUT WERE GENERALLY BEING HELD IN CHECK AROUND 10 KT.
GRADIENT IS NOT STRONG. AS ALWAYS WILL NEED TO WATCH THE NORTHERLY
FETCH...BUT GUIDANCE KEEPS SPEEDS BELOW SMALL CRAFT ADVISORY
THRESHOLDS.
WINDS SHOULD REMAIN BELOW SCA LVLS THRU THU. A STRONG COLD FROPA THU
NGT WILL LEAD TO SCA CONDITIONS OVRNGT THU THRU SAT. DEPENDING ON
HOW MUCH MIXING TAKES PLACE...GUSTS COULD APPROACH GALE WARNING
CRITERIA FRI.
&&
.TIDES/COASTAL FLOODING...
WATER LEVELS WERE RUNNING A FOOT TO FOOT AND A HALF ABOVE NORMAL
THIS MORNING. FORTUNATELY...THE ASTRONOMICAL TIDE IS NOT EXTREMELY
HIGH TODAY INTO WEDNESDAY...AND EVEN THESE ANOMALIES WILL LIKELY
BE UNDER MINOR TIDAL FLOODING THRESHOLDS. THIS IS SUPPORTED BY THE
MDL EXTRATROPICAL MODEL AND CBOFS. THEREFORE...NOT EXPECTING TO
ISSUE A COASTAL FLOOD ADVISORY AT THIS TIME.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
PELOQUIN/WOODY!/JRK
000
FXUS61 KLWX 240907
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
407 AM EST TUE NOV 24 2009
.SYNOPSIS...
LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL TRACK EAST OF CAPE
COD THIS AFTERNOON. HIGH PRESSURE WILL BUILD IN BEHIND THIS SYSTEM
TODAY INTO WEDNESDAY. A STORM SYSTEM AND ITS ASSOCIATED COLD FRONT
WILL PASS THROUGH THURSDAY...AND AN UPPER-LEVEL LOW BEHIND THIS
FRONT WILL BRING UNSETTLED CONDITIONS LATE IN THE WEEK. HIGH
PRESSURE WILL MOVE INTO THE AREA FOR THE WEEKEND.
&&
.NEAR TERM /TODAY/...
LOW PRES HAS BEEN SLOW TO DEPART THE NC CST...KEEPING MID ATLC
LOCKED IN NE FLOW AND PDS OF RA/DZ. THE LOW RMNS PROGGED TO MOVE
NE TDA...WHICH WL BRING AN END TO THE STEADIER RA BUT THERE IS NO
MECHANISM TO SWEEP THE RMNG LO LVL MOISTURE OUT...SO CWA WL CONT
TO XPRNC CONSIDERABLE LO CLDS ALONG W/ PDS OF DZ. VERY LTL MVMNT
OF TEMPS - YDA HIGHS WERE IN U40S-L50S...AND THAT`S WHAT SHOULD
HAPPEN AGN TDA.
&&
.SHORT TERM /TONIGHT/...
TNGT YOU COULD THINK OF IT AS THE MID ATLC WL BE UNDER WK HIGH
PRES OR THAT IT WL BE IN BTWN SYSTEMS. EITHER WAY LO LVL MOISTURE
WL RMN OVR THE CWA BRINGING XTNSV CLD CVR...AND PSBLY PLENTY OF
FOG TNGT. MDLS ARE PREDICTING VSBYS BLO 1NM TNGT...I`M ALWAYS
SKEPTICAL OF REALLY TANKING THE VSBY 24 HRS IN ADVANCE UNLESS
WE`RE GOING TO XPRNC TOP NOTCH RAD CONDS..AND I DON`T THINK THIS
WL NOT BE ONE OF THOSE NGTS. HOWEVER I`LL STILL MENTION FOG/DZ IN
THE GRIDDS OVRNGT AND IF LATER SHIFTS THINK DIFFERENTLY THEY CAN TAKE
VSBYS BLO 1SM FOR TNGT. AGN LTL MVMNT OF TEMPS - RANGE WL BE FM
L40S IN THE HIGHLANDS TO A50 ON THE BAY.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
LEAD SHORTWAVE ENERGY EMBEDDED IN C CONUS H5 TROUGH WILL LIFT NWD
THRU THE GREAT LAKES WED. ISENTROPIC LIFT AIDED BY SLY LLVL FLOW AND
DPVA AHEAD OF SHORTWAVE TROUGH SHOULD PROVIDE ENOUGH FORCING FOR LGT
SHOWERS DURING THE DAY WED.
NEXT UPPER SHORTWAVE ENERGY WILL BE QUICK TO FOLLOW...DIGGING AROUND
BACKSIDE OF SYNOPTIC-SCALE UPPER TROUGH WED/WED NGT. HEIGHT FALLS
AHEAD OF THE UPPER TROUGH WILL LEAD TO COASTAL CYCLOGENESIS JUST OFF
THE SE COAST LATE WED. SFC LOW WILL TRACK NEWD BUT SHOULD TRACK TOO
FAR OFF THE COAST TO HAVE A DIRECT IMPACT TO OUR CWFA. HOWEVER...
AMPLIFYING UPPER LOW AND STRENGTHENING THERMAL GRADIENT WILL PROVIDE
FORCING FOR ASCENT AND PRECIP SHOULD INCREASE IN COVERAGE THU/THU
NGT. 00Z SUITE OF MODELS SLIGHTLY SLOWER THAN PREV RUNS WITH THIS
SYSTEM...AND THEREFORE MAJORITY OF THE SHOWER ACTIVITY MIGHT HOLD
OFF UNTIL THE LATE AFTN/ERY EVNG ON THANKSGIVING. ATMOSPHERE WILL
QUICKLY COOL BEHIND STRONG COLD FROPA THU NGT. THERMAL PROFILES
APPEAR TO BE COLD ENOUGH TO SUPPORT PRECIP CHANGING TO SNOW ACROSS
THE POTOMAC HIGHLANDS LATE THU NGT...AND POSSIBLY A RAIN/SNOW MIX AS
FAR E AS THE BLUE RIDGE.
CUTOFF LOW TRACKING OVER NEW ENGLAND WILL SLOW DOWN FRI AS UPPER
TROUGH ACQUIRES NEGATIVE TILT. BREEZY CONDITIONS EXPECTED FRI AS
STRONG CAA WILL STEEPEN LLVL LAPSE RATES AND ALLOW FOR STRONGER
WINDS ALOFT TO MIX DOWN TO THE SFC. CORE OF COLD AIRMASS WILL BE
OVRHD FRI NGT WITH A LGT RA/SN MIX AS FAR E AS I-95. UPSLOPE FLOW
AROUND THE UPPER LOW MAY LEAD TO AN ACCUMULATING SNOW EVENT ACROSS
THE WRN SLOPES OF THE ALLEGHENY FRONT AND POTOMAC HIGHLANDS THU NGT
LASTING THRU SAT. TOO ERLY TO NAIL DOWN SPECIFIC SNOWFALL
ACCUMULATIONS BUT THERE IS INCREASING CONFIDENCE FOR WINTER-
WEATHER ADVISORY ACCUMULATIONS.
HIPRES BUILDS BACK INTO THE AREA SUN...BEFORE THE NEXT STORM SYSTEM
APPROACHES ERY NEXT WEEK.
&&
.AVIATION /TODAY THROUGH SATURDAY/...
ALL AIRPORTS IN THE MID ATLC STATES WL XPRNC XTNSV LOW LVL
MOISTURE TDA AND TNGT. THIS WL BE MANIFESTED BY LO CIGS/POOR
VSBY/PDS OF DZ. IFR/LO MVFR WL BE BE THE RULE BOTH TDA AT ALL
SITES...PSBLY DROPPING TO LIFR OVRGNT.
A STORM SYSTEM WILL APPROACH THE AREA WED WITH SCT SHOWERS AND MVFR
CIGS. A STRONG UPPER LOW WILL QUICKLY FOLLOW THU-THU NGT...BRINGING
MORE CHANCES FOR PRECIP. IN WAKE OF STRONG COLD FROPA THU NGT...SHSN
MAY MIX IN WITH SHRA AT MRB THU NGT. GUSTY WINDS NW WINDS ARE
EXPECTED ACROSS ALL TERMINALS FRI...LASTING INTO SAT.
&&
.MARINE...
WINDS HV DROPPED BLO SCA VALUES. LOW PRES WL BE TRACKING AWAY FM
THE WATERS TDA LVG LTL PRES GRAD GRAD. NO PROBS ON WATERS TDA/TNGT
OUTSIDE OF PTNL FOR POOR VSBYS IN FOG TNGT.
WINDS SHOULD REMAIN BELOW SCA LVLS THRU THU. A STRONG COLD FROPA THU
NGT WILL LEAD TO SCA CONDITIONS OVRNGT THU THRU SAT. DEPENDING ON
HOW MUCH MIXING TAKES PLACE...GUSTS COULD APPROACH GALE WARNING
CRITERIA FRI.
&&
.TIDES/COASTAL FLOODING...
WATER LVLS AT DC...ALEX...AND BALT IN THE MDNGT TIDAL CYCLE RAN
CLOSE TO MINOR FLDG...BUT ALL STAYED BLO. CALLED THE ALEX EOC BUT
THEY HAD NO FLDG "OF THE USUAL SUSPECTS." WINDS WL RMN FM THE NE
TDA...AND ALTHO NOT STRONG THIS WON`T AID IN THE DRAINING PROCESS.
HOWEVER THIS PAST TIDE CYCLE HAD THE HIGHEST LVLS OF TDA OR
WED...SO AM GOING TO REFRAIN FM ISSUING A CSTL FLD ADVSRY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
PRODUCTS...WOODY!/JRK
000
FXUS61 KLWX 240155 AAB
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
855 PM EST MON NOV 23 2009
.SYNOPSIS...
LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST TOWARD NEW
ENGLAND OVERNIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THIS SYSTEM
TUESDAY INTO WEDNESDAY. A STORM SYSTEM AND ITS ASSOCIATED COLD
FRONT WILL PASS THROUGH THURSDAY...AND AN UPPER-LEVEL LOW BEHIND
THIS FRONT WILL BRING UNSETTLED CONDITIONS LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
HAVE ISSUED A SECOND UPDATE TO DELAY EROSION OF LIGHT PCPN
CURRENTLY ONGOING ACRS MUCH OF FCST AREA. INTENSITY HAS BEEN
DOWNWARD...BUT LIGHT PCPN XPCD TO LINGER THRU LATE TNGT...AFTER
WHICH SUSTAINED LOW CLDS AND FOG XPCD AMID ELEVATED MINIMA IN NEAR-
SATURATED AIR. PREV DISCUSSION FOLLOWS...
RAIN CONTS TO DVLP ALONG APPARENT BACK EDGE OF ECHO ON
RADAR... ALTHOUGH THE BACK EDGE IS LKLY PARTIALLY A RESULT OF THE
BEAM OVERSHOOTING LOW-LVL PCPN. LATEST MODELS DEPICT SLOWER EXIT
TO PCPN. HAVE UPDATED FIRST SIX HRS OF FCST TO SHOW SAME TREND. BY
LATE TNGT...XPC ISENTROPIC LIFT TO DECR AS SFC LOPRES MOVES TWD
NEW ENGLAND. PCPN SHUD WANE...BUT CLDS WILL PERSIST. PREV
DISCUSSION FOLLOWS...
CURRENT ANALYSIS SHOWS LOW PRESSURE OFF THE NORTH CAROLINA COAST
THIS AFTERNOON. HIGH PRESSURE OVER EASTERN CANADA EXTENDS INTO NEW
ENGLAND. A SERIES OF WEAK UPPER- LEVEL DISTURBANCES EXTEND FROM
NEW JERSEY THROUGH THE MID-ATLANTIC AND INTO THE OHIO VALLEY.
LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL MOVE NORTHEAST
TOWARDS NEW ENGLAND TONIGHT. AN EASTERLY FLOW AT THE LOW-LEVELS WILL
CONTINUE TO BRING MOISTURE IN OFF THE ATLANTIC OCEAN RESULTING IN
LOW CLOUDS ALONG WITH SOME RAIN AND DRIZZLE THIS EVENING. THE BEST
CHANCE FOR RAIN WILL BE ACROSS THE EASTERN CWA WHERE THERE IS SOME
MID-LEVEL SUPPORT FROM AND UPPER-LEVEL DISTURBANCE. AS THE LOW MOVES
TOWARD NEW ENGLAND OVERNIGHT...HIGH PRESSURE WILL SLOWLY REBUILD
INTO THE REGION FROM THE NORTH. HOWEVER...LOW-LEVEL MOISTURE WILL
REMAIN TRAPPED UNDERNEATH THE SUBSIDENCE INVERSION BRINGING MORE
CLOUDS ALONG WITH AREAS OF DRIZZLE AND LIGHT RAIN. THE BEST CHANCE
FOR LIGHT RAIN WILL BE ACROSS THE NORTHEASTERN CWA. HAVE ALSO ADDED
AREAS OF FOG IN THE HIGHER ELEVATIONS DUE TO LOW CIGS.
MIN TEMPS WILL RANGE FROM THE UPPER 30S IN PORTIONS OF THE POTOMAC
HIGHLANDS TO THE LOWER AND MIDDLE 40S ACROSS MOST OTHER LOCATIONS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
SURFACE HIGH WILL BUILD OVER THE REGION TUESDAY. A MID-LEVEL RIDGE
AXIS WILL STRENGTHEN OVER THE AREA AHEAD OF AN UPPER-LEVEL LOW OVER
THE MIDWEST. DESPITE THE BUILDING HIGH PRESSURE...LOW-LEVEL MOISTURE
WILL REMAIN TRAPPED UNDERNEATH THE SUBSIDENCE INVERSION RESULTING IN
LOW CLOUDS ALONG WITH AREAS OF DRIZZLE...ESPECIALLY ACROSS THE
EASTERN CWA.
MAX TEMPS WILL BE IN THE 50S FOR MOST LOCATIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
RDG OF SFC HIPRES DOWN ERN SEABRD TUE NGT. HWVR...RDG NARROW AND
PLENTY OF LLVL MSTR TRAPPED BENEATH INVSN...MAKING THIS SETUP LOOK A
LOT LIKE CAD. WL FCST CLDY SKIES AND PATCHY DZ-- SCHC THAT
MEASUREABLE RAFL WL TAKE PLACE.
MEANWHILE...A COMPLX SCENARIO ESTABLISHING IN THE CENTER OF THE
CONUS...AS S/WV ENERGY DROPS INTO MEAN TROF...CUTTING OFF H5 LOW.
SYNOPTIC SCALE GDNC DISPLAYING TYPICAL DIFFS IN PLACEMENT/STRENGTH
OF THAT LOW. NONETHELESS...THAT CYCLONE SHUD SEND OUT A LEAD WV...
WHICH WL CROSS CWFA AND ASSIST IN DVLPG LGT SHRA WED AFTN-NGT. SHUD
HV A SLY COMPONENT TO THE SFC FLOW /MOST LKLY SELY/ AHD OF THIS
WV...BUT AM HESITANT TO JUMP ON IT COMPLETELY...CONSIDERING THE
DEPTH OF BLYR BASED SATURATION AND THE PROPENSITY OF GDNC TO ERODE
IT TOO QUICKLY.
BY THU /THXGVG/...YET MORE S/WV ENERGY WL DROP INTO H5 MEAN TROF
POSN...FURTHER ENHANCING CUTOFF LOW. SINCE CWFA WL BE AHD OF THIS
ACTVTY...DONT THINK THERE WL BE MUCH TO BE CONCERNED ABT AT START.
BUT...LOOKING FOR SHARP CFP THU AFTN. BASED ON KINEMATIC/THERMAL
CONTRAST...SHUD BE SUFFICIENT FORCING FOR SHRA TO DVLP ALNG FNT BY
DAYS END.
HV NOT MADE MANY MAX/MIN TEMP ADJUSTMENTS THRU THIS PD. IN
GENERAL...THE DIURNAL SPREAD SHUD BE LMTD BY AMPLE CLDCVR. IF THERE
WERE AN OPPORTUNITY FOR CLDS TO BREAK...ITS LOOKING LIKE AFTER THE
LEAD VORT WED. SO...WED NGT WL BE A PINCH COOLER THAN TUE NGT.
SIMILARLY...CUD BE A LTL WAA AHD OF CFP THU AFTN...AND THAT/S
EVIDENT IN THU MAXT FCST.
H5 LOPRES OVR GRTLKS WL TRANSFER OFF THE ATLC CST THU NGT...AND
RSLTNT SFC CYCLONE WL RAPIDLY DEEPEN AS IT HEADS TWD NEW ENGLND FRI.
CAA WL ENSUE...BUT NOT AS COLD AS TYPICAL-- H8 DOWN TO ABT -5C/H10-8
TKNS TO ABT 1300M. FOR THIS PTTN PCPN VRY LKLY...AND SNW CERTAINLY
PSBL...SPCLY FOR THE MTNS. EACH SUCCESSIVE MDL RUN SUGGESTS UPR
LOW WL BE STRONGER...AND THIS BOLSTERING CONFIDENCE IN SYSTEM
EVOLUTION. ITS JUST THE DETAILS TO PIN DOWN NOW...WHICH INCL THE
EXTENT OF SNW/PSBL ACCUMS.
TROF AXIS PIVOTS ACRS FRI/FRI NGT...WHICH WL BE WHEN THE CORE OF THE
COLD AIR WL BE OHD. BASED ON THERMAL PROFILES...ANY APPRECIABLE PCPN
OR ANY S/WV SUPPORT WUD BE SUFFICIENT TO BRING SNW TO SFC ANYWHERE
IN CWFA. ONLY QSTN WL BE HOW MUCH MSTR WL BE LEFT...AS NW
FLOW/ADVECTIVE PROCESSES SHUD ALSO BE QUITE EFFICIENT AT SCOURING
OUT LLVL MSTR. IT MAY TAKE PVA TO DO IT. HIER POPS ACRS MTNS...BUT
20/30 POPS ACRS MUCH OF MD/NEIGHBORING VA.
HIPRES RDG FOR THE WKND STARTING TO LOOK MORE COMPRESSED AS STORM
SYSTEMS PICK UP PACE ACRS CONUS. NXT FROPA LURKING BY MON.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
PCPN XPCD TO CONTINUE AT TERMINALS THRU LATE TNGT. THUS...LOW CIGS
AND VSBYS /GENLY IFR WITH OCSNL LIFR CIGS PSBL/ WILL RESULT IN
FLIGHT RESTRICTIONS FOR MUCH OF NEXT 24 HRS. EVEN AFTER DEPARTURE
OF PCPN...FOG SHUD DVLP IN NEAR- SATURATED AMS. ALTHOUGH VSBYS
IMPROVE SOMEWHAT TMW...CLDS XPCD TO RMN IN PLACE AS COOL SATURATED
AIR WILL BE TRAPPED BENEATH STRONG INVERSION ALOFT.
XTNDD PD OF UNSTTLD WX CONDS TUE NGT AND INTO ELY WED. FLGT
RESTRICTIONS WL BE MOST PREVALENT IN TERMS OF CIGS...WHERE AOB IFR
XPCTD. VSBYS LKLY TO BE RESTRICTED AS WELL...MVFR IF NOT IFR.
PD OF SHRA W/ UPR DISTURBANCE CUD MIX LLVLS ENUF FOR RESTRICTIONS TO
LIFT SOMEWHAT WED AFTN-EVE...BUT MVFR STILL PROBABLE. WL HV TO WAIT
TIL STRONG CFP LT THU FOR VFR CONDS TO RTN...BUT GUSTY NW WNDS WL
ACCMPNY THAT PTTN CHG.
&&
.MARINE...
SMALL CRAFT ADZY RMNS IN EFFECT FOR MAIN CHANNEL OF CHSPK BAY THRU
TNGT...WHERE CUSTS 18-25 KT STILL NOTED. RMNDR OF PREV ADZY
ALLOWED TO EXPIRE AT 8 PM.
WINDS WILL DIMINISH BELOW SCA LEVELS BY TUESDAY AS HIGH PRESSURE
BUILDS CLOSER.
RDG OF HIPRES AND SATD AMS THRU WED...WHICH WL INHIBIT WNDS FM
MIXING TO SFC. NO FLAGS XPCTD TIL LT THU...WHEN CFP CROSSES WATERS.
&&
.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES STILL NOTED AS SFC LOPRES MOVES NWD ALONG
COASTLINE. HOWEVER...SFC WINDS HAVE BCM MORE NLY...LMTG ONSHORE
FLOW. TIDE LEVELS XPCD TO RMN BLW ADZY THRESHOLDS...AND NO COASTAL
FLOODING IS ANTICIPATED.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ531>534-537-
539>541-543.
&&
$$
UPDATE...KRAMAR
PREV DISCUSSION...KRAMAR/LASORSA/HTS
000
FXUS61 KLWX 232240 AAA
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
540 PM EST MON NOV 23 2009
.SYNOPSIS...
LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST THIS EVENING AND
TOWARDS NEW ENGLAND OVERNIGHT. HIGH PRESSURE WILL BUILD IN BEHIND
THIS SYSTEM TUESDAY INTO WEDNESDAY. A STORM SYSTEM AND ITS
ASSOCIATED COLD FRONT WILL PASS THROUGH THURSDAY...AND AN UPPER-
LEVEL LOW BEHIND THIS FRONT WILL BRING UNSETTLED CONDITIONS LATE
IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
RAIN CONTS TO DVLP ALONG APPARENT BACK EDGE OF ECHO ON
RADAR... ALTHOUGH THE BACK EDGE IS LKLY PARTIALLY A RESULT OF THE
BEAM OVERSHOOTING LOW-LVL PCPN. LATEST MODELS DEPICT SLOWER EXIT
TO PCPN. HAVE UPDATED FIRST SIX HRS OF FCST TO SHOW SAME TREND. BY
LATE TNGT...XPC ISENTROPIC LIFT TO DECR AS SFC LOPRES MOVES TWD
NEW ENGLAND. PCPN SHUD WANE...BUT CLDS WILL PERSIST. PREV
DISCUSSION FOLLOWS...
CURRENT ANALYSIS SHOWS LOW PRESSURE OFF THE NORTH CAROLINA COAST
THIS AFTERNOON. HIGH PRESSURE OVER EASTERN CANADA EXTENDS INTO NEW
ENGLAND. A SERIES OF WEAK UPPER- LEVEL DISTURBANCES EXTEND FROM
NEW JERSEY THROUGH THE MID-ATLANTIC AND INTO THE OHIO VALLEY.
LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL MOVE NORTHEAST
TOWARDS NEW ENGLAND TONIGHT. AN EASTERLY FLOW AT THE LOW-LEVELS WILL
CONTINUE TO BRING MOISTURE IN OFF THE ATLANTIC OCEAN RESULTING IN
LOW CLOUDS ALONG WITH SOME RAIN AND DRIZZLE THIS EVENING. THE BEST
CHANCE FOR RAIN WILL BE ACROSS THE EASTERN CWA WHERE THERE IS SOME
MID-LEVEL SUPPORT FROM AND UPPER-LEVEL DISTURBANCE. AS THE LOW MOVES
TOWARD NEW ENGLAND OVERNIGHT...HIGH PRESSURE WILL SLOWLY REBUILD
INTO THE REGION FROM THE NORTH. HOWEVER...LOW-LEVEL MOISTURE WILL
REMAIN TRAPPED UNDERNEATH THE SUBSIDENCE INVERSION BRINGING MORE
CLOUDS ALONG WITH AREAS OF DRIZZLE AND LIGHT RAIN. THE BEST CHANCE
FOR LIGHT RAIN WILL BE ACROSS THE NORTHEASTERN CWA. HAVE ALSO ADDED
AREAS OF FOG IN THE HIGHER ELEVATIONS DUE TO LOW CIGS.
MIN TEMPS WILL RANGE FROM THE UPPER 30S IN PORTIONS OF THE POTOMAC
HIGHLANDS TO THE LOWER AND MIDDLE 40S ACROSS MOST OTHER LOCATIONS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
SURFACE HIGH WILL BUILD OVER THE REGION TUESDAY. A MID-LEVEL RIDGE
AXIS WILL STRENGTHEN OVER THE AREA AHEAD OF AN UPPER-LEVEL LOW OVER
THE MIDWEST. DESPITE THE BUILDING HIGH PRESSURE...LOW-LEVEL MOISTURE
WILL REMAIN TRAPPED UNDERNEATH THE SUBSIDENCE INVERSION RESULTING IN
LOW CLOUDS ALONG WITH AREAS OF DRIZZLE...ESPECIALLY ACROSS THE
EASTERN CWA.
MAX TEMPS WILL BE IN THE 50S FOR MOST LOCATIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
RDG OF SFC HIPRES DOWN ERN SEABRD TUE NGT. HWVR...RDG NARROW AND
PLENTY OF LLVL MSTR TRAPPED BENEATH INVSN...MAKING THIS SETUP LOOK A
LOT LIKE CAD. WL FCST CLDY SKIES AND PATCHY DZ-- SCHC THAT
MEASUREABLE RAFL WL TAKE PLACE.
MEANWHILE...A COMPLX SCENARIO ESTABLISHING IN THE CENTER OF THE
CONUS...AS S/WV ENERGY DROPS INTO MEAN TROF...CUTTING OFF H5 LOW.
SYNOPTIC SCALE GDNC DISPLAYING TYPICAL DIFFS IN PLACEMENT/STRENGTH
OF THAT LOW. NONETHELESS...THAT CYCLONE SHUD SEND OUT A LEAD WV...
WHICH WL CROSS CWFA AND ASSIST IN DVLPG LGT SHRA WED AFTN-NGT. SHUD
HV A SLY COMPONENT TO THE SFC FLOW /MOST LKLY SELY/ AHD OF THIS
WV...BUT AM HESITANT TO JUMP ON IT COMPLETELY...CONSIDERING THE
DEPTH OF BLYR BASED SATURATION AND THE PROPENSITY OF GDNC TO ERODE
IT TOO QUICKLY.
BY THU /THXGVG/...YET MORE S/WV ENERGY WL DROP INTO H5 MEAN TROF
POSN...FURTHER ENHANCING CUTOFF LOW. SINCE CWFA WL BE AHD OF THIS
ACTVTY...DONT THINK THERE WL BE MUCH TO BE CONCERNED ABT AT START.
BUT...LOOKING FOR SHARP CFP THU AFTN. BASED ON KINEMATIC/THERMAL
CONTRAST...SHUD BE SUFFICIENT FORCING FOR SHRA TO DVLP ALNG FNT BY
DAYS END.
HV NOT MADE MANY MAX/MIN TEMP ADJUSTMENTS THRU THIS PD. IN
GENERAL...THE DIURNAL SPREAD SHUD BE LMTD BY AMPLE CLDCVR. IF THERE
WERE AN OPPORTUNITY FOR CLDS TO BREAK...ITS LOOKING LIKE AFTER THE
LEAD VORT WED. SO...WED NGT WL BE A PINCH COOLER THAN TUE NGT.
SIMILARLY...CUD BE A LTL WAA AHD OF CFP THU AFTN...AND THAT/S
EVIDENT IN THU MAXT FCST.
H5 LOPRES OVR GRTLKS WL TRANSFER OFF THE ATLC CST THU NGT...AND
RSLTNT SFC CYCLONE WL RAPIDLY DEEPEN AS IT HEADS TWD NEW ENGLND FRI.
CAA WL ENSUE...BUT NOT AS COLD AS TYPICAL-- H8 DOWN TO ABT -5C/H10-8
TKNS TO ABT 1300M. FOR THIS PTTN PCPN VRY LKLY...AND SNW CERTAINLY
PSBL...SPCLY FOR THE MTNS. EACH SUCCESSIVE MDL RUN SUGGESTS UPR
LOW WL BE STRONGER...AND THIS BOLSTERING CONFIDENCE IN SYSTEM
EVOLUTION. ITS JUST THE DETAILS TO PIN DOWN NOW...WHICH INCL THE
EXTENT OF SNW/PSBL ACCUMS.
TROF AXIS PIVOTS ACRS FRI/FRI NGT...WHICH WL BE WHEN THE CORE OF THE
COLD AIR WL BE OHD. BASED ON THERMAL PROFILES...ANY APPRECIABLE PCPN
OR ANY S/WV SUPPORT WUD BE SUFFICIENT TO BRING SNW TO SFC ANYWHERE
IN CWFA. ONLY QSTN WL BE HOW MUCH MSTR WL BE LEFT...AS NW
FLOW/ADVECTIVE PROCESSES SHUD ALSO BE QUITE EFFICIENT AT SCOURING
OUT LLVL MSTR. IT MAY TAKE PVA TO DO IT. HIER POPS ACRS MTNS...BUT
20/30 POPS ACRS MUCH OF MD/NEIGHBORING VA.
HIPRES RDG FOR THE WKND STARTING TO LOOK MORE COMPRESSED AS STORM
SYSTEMS PICK UP PACE ACRS CONUS. NXT FROPA LURKING BY MON.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL HEAD TOWARDS NEW
ENGLAND TONIGHT. RAIN THIS AFTERNOON WILL TAPER OFF TO AREAS OF
DRIZZLE THIS EVENING INTO THE OVERNIGHT. HIGH PRESSURE WILL BUILD IN
BEHIND THIS SYSTEM LATE TONIGHT AND TUESDAY. HOWEVER...LOW-LEVEL
MOISTURE WILL REMAIN TRAPPED UNDERNEATH THE INVERSION BRINGING MORE
LOW CLOUDS THROUGH TUESDAY ALONG WITH AREAS OF DRIZZLE.
MVFR/IFR CIGS THIS AFTERNOON WILL LIKELY BECOME MAINLY IFR TONIGHT.
THERE IS SOME UNCERTAINTY IN THE VSBY FORECAST. VSBYS MAY FLUCTUATE
BETWEEN MVFR/IFR LEVELS THROUGH TONGIHT BEFORE TRENDING TOWARD VFR
LEVELS LATER TUESDAY.
XTNDD PD OF UNSTTLD WX CONDS TUE NGT AND INTO ELY WED. FLGT
RESTRICTIONS WL BE MOST PREVALENT IN TERMS OF CIGS...WHERE AOB IFR
XPCTD. VSBYS LKLY TO BE RESTRICTED AS WELL...MVFR IF NOT IFR.
PD OF SHRA W/ UPR DISTURBANCE CUD MIX LLVLS ENUF FOR RESTRICTIONS TO
LIFT SOMEWHAT WED AFTN-EVE...BUT MVFR STILL PROBABLE. WL HV TO WAIT
TIL STRONG CFP LT THU FOR VFR CONDS TO RTN...BUT GUSTY NW WNDS WL
ACCMPNY THAT PTTN CHG.
&&
.MARINE...
WILL CONTINUE WITH A SMALL CRAFT ADVISORY UNTIL 8 PM THIS EVENING
FOR THE CHESAPEAKE BAY NORTH OF POOLES ISLAND AS WELL AS THE
PATAPSCO RIVER AND THE PATUXENT RIVER. A SMALL CRAFT ADVISORY
REMAINS IN EFFECT UNTIL 5 AM FOR THE LOWER TIDAL POTOMAC AND THE
REST OF THE CHESAPEAKE BAY. A PRESSURE GRADIENT BETWEEN HIGH
PRESSURE OVER EASTERN CANADA AND LOW PRESSURE PASSING BY TO OUR EAST
WILL RESULT IN THE SCA WIND GUSTS.
WINDS WILL DIMINISH BELOW SCA LEVELS BY TUESDAY AS HIGH PRESSURE
BUILDS CLOSER.
RDG OF HIPRES AND SATD AMS THRU WED...WHICH WL INHIBIT WNDS FM
MIXING TO SFC. NO FLAGS XPCTD TIL LT THU...WHEN CFP CROSSES WATERS.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES ARE CURRENTLY RUNNING ABOUT ONE TO ONE AND ONE HALF
FEET ABOVE NORMAL THIS AFTERNOON. AS LOW PRESSURE TRACKS UP THE
MID-ATLANTIC COAST TONIGHT...A PERSISTENT ONSHORE FLOW WILL
CONTINUE...BRINGING MORE POSITIVE TIDAL ANOMALIES. HOWEVER...
ANOMALIES ARE NOT EXPECTED TO INCREASE MUCH TONIGHT WITH THE FLOW
TURNING MORE TOWARDS THE NORTH-NORTHEAST BEHIND THE SURFACE LOW.
LATEST CBOFS AS WELL AS EXTRA TROPICAL MODELS CONTINUE TO KEEP
WATER LEVELS JUST BELOW THRESHOLDS FOR MINOR COASTAL FLOODING.
WITH THE LUNAR CYCLE NEAR FIRST QUARTER...THE ASTRONOMICAL NORMS
ARE LOWER. WILL NOT ISSUE A COASTAL FLOOD ADVISORY FOR THOSE
REASONS...BUT WILL CONTINUE TO MONITOR THE TIDAL ANOMALIES THROUGH
TONIGHT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ531>534-537-
539>541-543.
SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR ANZ530-
538-542.
&&
$$
UPDATE...KRAMAR
PREV DISCUSSION...LASORSA/HTS
000
FXUS61 KLWX 232002
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
302 PM EST MON NOV 23 2009
.SYNOPSIS...
LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST THIS EVENING AND
TOWARDS NEW ENGLAND OVERNIGHT. HIGH PRESSURE WILL BUILD IN BEHIND
THIS SYSTEM TUESDAY INTO WEDNESDAY. A STORM SYSTEM AND ITS
ASSOCIATED COLD FRONT WILL PASS THROUGH THURSDAY AND AN UPPER-LEVEL
LOW BEHIND THIS FRONT WILL BRING UNSETTLED CONDITIONS LATE IN THE
WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
CURRENT ANALYSIS SHOWS LOW PRESSURE OFF THE NORTH CAROLINA COAST
THIS AFTERNOON. HIGH PRESSURE OVER EASTERN CANADA EXTENDS INTO NEW
ENGLAND. A SERIES OF WEAK UPPER-LEVEL DISTURBANCES EXTEND FROM NEW
JERSEY THROUGH THE MID-ATLANTIC AND INTO THE OHIO VALLEY.
LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL MOVE NORTHEAST
TOWARDS NEW ENGLAND TONIGHT. AN EASTERLY FLOW AT THE LOW-LEVELS WILL
CONTINUE TO BRING MOISTURE IN OFF THE ATLANTIC OCEAN RESULTING IN
LOW CLOUDS ALONG WITH SOME RAIN AND DRIZZLE THIS EVENING. THE BEST
CHANCE FOR RAIN WILL BE ACROSS THE EASTERN CWA WHERE THERE IS SOME
MID-LEVEL SUPPORT FROM AND UPPER-LEVEL DISTURBANCE. AS THE LOW MOVES
TOWARD NEW ENGLAND OVERNIGHT...HIGH PRESSURE WILL SLOWLY REBUILD
INTO THE REGION FROM THE NORTH. HOWEVER...LOW-LEVEL MOISTURE WILL
REMAIN TRAPPED UNDERNEATH THE SUBSIDENCE INVERSION BRINGING MORE
CLOUDS ALONG WITH AREAS OF DRIZZLE AND LIGHT RAIN. THE BEST CHANCE
FOR LIGHT RAIN WILL BE ACROSS THE NORTHEASTERN CWA. HAVE ALSO ADDED
AREAS OF FOG IN THE HIGHER ELEVATIONS DUE TO LOW CIGS.
MIN TEMPS WILL RANGE FROM THE UPPER 30S IN PORTIONS OF THE POTOMAC
HIGHLANDS TO THE LOWER AND MIDDLE 40S ACROSS MOST OTHER LOCATIONS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
SURFACE HIGH WILL BUILD OVER THE REGION TUESDAY. A MID-LEVEL RIDGE
AXIS WILL STRENGTHEN OVER THE AREA AHEAD OF AN UPPER-LEVEL LOW OVER
THE MIDWEST. DESPITE THE BUILDING HIGH PRESSURE...LOW-LEVEL MOISTURE
WILL REMAIN TRAPPED UNDERNEATH THE SUBSIDENCE INVERSION RESULTING IN
LOW CLOUDS ALONG WITH AREAS OF DRIZZLE...ESPECIALLY ACROSS THE
EASTERN CWA.
MAX TEMPS WILL BE IN THE 50S FOR MOST LOCATIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
RDG OF SFC HIPRES DOWN ERN SEABRD TUE NGT. HWVR...RDG NARROW AND
PLENTY OF LLVL MSTR TRAPPED BENEATH INVSN...MAKING THIS SETUP LOOK A
LOT LIKE CAD. WL FCST CLDY SKIES AND PATCHY DZ-- SCHC THAT
MEASUREABLE RAFL WL TAKE PLACE.
MEANWHILE...A COMPLX SCENARIO ESTABLISHING IN THE CENTER OF THE
CONUS...AS S/WV ENERGY DROPS INTO MEAN TROF...CUTTING OFF H5 LOW.
SYNOPTIC SCALE GDNC DISPLAYING TYPICAL DIFFS IN PLACEMENT/STRENGTH
OF THAT LOW. NONETHELESS...THAT CYCLONE SHUD SEND OUT A LEAD WV...
WHICH WL CROSS CWFA AND ASSIST IN DVLPG LGT SHRA WED AFTN-NGT. SHUD
HV A SLY COMPONENT TO THE SFC FLOW /MOST LKLY SELY/ AHD OF THIS
WV...BUT AM HESITANT TO JUMP ON IT COMPLETELY...CONSIDERING THE
DEPTH OF BLYR BASED SATURATION AND THE PROPENSITY OF GDNC TO ERODE
IT TOO QUICKLY.
BY THU /THXGVG/...YET MORE S/WV ENERGY WL DROP INTO H5 MEAN TROF
POSN...FURTHER ENHANCING CUTOFF LOW. SINCE CWFA WL BE AHD OF THIS
ACTVTY...DONT THINK THERE WL BE MUCH TO BE CONCERNED ABT AT START.
BUT...LOOKING FOR SHARP CFP THU AFTN. BASED ON KINEMATIC/THERMAL
CONTRAST...SHUD BE SUFFICIENT FORCING FOR SHRA TO DVLP ALNG FNT BY
DAYS END.
HV NOT MADE MANY MAX/MIN TEMP ADJUSTMENTS THRU THIS PD. IN
GENERAL...THE DIURNAL SPREAD SHUD BE LMTD BY AMPLE CLDCVR. IF THERE
WERE AN OPPORTUNITY FOR CLDS TO BREAK...ITS LOOKING LIKE AFTER THE
LEAD VORT WED. SO...WED NGT WL BE A PINCH COOLER THAN TUE NGT.
SIMILARLY...CUD BE A LTL WAA AHD OF CFP THU AFTN...AND THAT/S
EVIDENT IN THU MAXT FCST.
H5 LOPRES OVR GRTLKS WL TRANSFER OFF THE ATLC CST THU NGT...AND
RSLTNT SFC CYCLONE WL RAPIDLY DEEPEN AS IT HEADS TWD NEW ENGLND FRI.
CAA WL ENSUE...BUT NOT AS COLD AS TYPICAL-- H8 DOWN TO ABT -5C/H10-8
TKNS TO ABT 1300M. FOR THIS PTTN PCPN VRY LKLY...AND SNW CERTAINLY
PSBL...SPCLY FOR THE MTNS. EACH SUCCESSIVE MDL RUN SUGGESTS UPR
LOW WL BE STRONGER...AND THIS BOLSTERING CONFIDENCE IN SYSTEM
EVOLUTION. ITS JUST THE DETAILS TO PIN DOWN NOW...WHICH INCL THE
EXTENT OF SNW/PSBL ACCUMS.
TROF AXIS PIVOTS ACRS FRI/FRI NGT...WHICH WL BE WHEN THE CORE OF THE
COLD AIR WL BE OHD. BASED ON THERMAL PROFILES...ANY APPRECIABLE PCPN
OR ANY S/WV SUPPORT WUD BE SUFFICIENT TO BRING SNW TO SFC ANYWHERE
IN CWFA. ONLY QSTN WL BE HOW MUCH MSTR WL BE LEFT...AS NW
FLOW/ADVECTIVE PROCESSES SHUD ALSO BE QUITE EFFICIENT AT SCOURING
OUT LLVL MSTR. IT MAY TAKE PVA TO DO IT. HIER POPS ACRS MTNS...BUT
20/30 POPS ACRS MUCH OF MD/NEIGHBORING VA.
HIPRES RDG FOR THE WKND STARTING TO LOOK MORE COMPRESSED AS STORM
SYSTEMS PICK UP PACE ACRS CONUS. NXT FROPA LURKING BY MON.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL HEAD TOWARDS NEW
ENGLAND TONIGHT. RAIN THIS AFTERNOON WILL TAPER OFF TO AREAS OF
DRIZZLE THIS EVENING INTO THE OVERNIGHT. HIGH PRESSURE WILL BUILD IN
BEHIND THIS SYSTEM LATE TONIGHT AND TUESDAY. HOWEVER...LOW-LEVEL
MOISTURE WILL REMAIN TRAPPED UNDERNEATH THE INVERSION BRINGING MORE
LOW CLOUDS THROUGH TUESDAY ALONG WITH AREAS OF DRIZZLE.
MVFR/IFR CIGS THIS AFTERNOON WILL LIKELY BECOME MAINLY IFR TONIGHT.
THERE IS SOME UNCERTAINTY IN THE VSBY FORECAST. VSBYS MAY FLUCTUATE
BETWEEN MVFR/IFR LEVELS THROUGH TONGIHT BEFORE TRENDING TOWARD VFR
LEVELS LATER TUESDAY.
XTNDD PD OF UNSTTLD WX CONDS TUE NGT AND INTO ELY WED. FLGT
RESTRICTIONS WL BE MOST PREVALENT IN TERMS OF CIGS...WHERE AOB IFR
XPCTD. VSBYS LKLY TO BE RESTRICTED AS WELL...MVFR IF NOT IFR.
PD OF SHRA W/ UPR DISTURBANCE CUD MIX LLVLS ENUF FOR RESTRICTIONS TO
LIFT SOMEWHAT WED AFTN-EVE...BUT MVFR STILL PROBABLE. WL HV TO WAIT
TIL STRONG CFP LT THU FOR VFR CONDS TO RTN...BUT GUSTY NW WNDS WL
ACCMPNY THAT PTTN CHG.
&&
.MARINE...
WILL CONTINUE WITH A SMALL CRAFT ADVISORY UNTIL 8 PM THIS EVENING
FOR THE CHESAPEAKE BAY NORTH OF POOLES ISLAND AS WELL AS THE
PATAPSCO RIVER AND THE PATUXENT RIVER. A SMALL CRAFT ADVISORY
REMAINS IN EFFECT UNTIL 5 AM FOR THE LOWER TIDAL POTOMAC AND THE
REST OF THE CHESAPEAKE BAY. A PRESSURE GRADIENT BETWEEN HIGH
PRESSURE OVER EASTERN CANADA AND LOW PRESSURE PASSING BY TO OUR EAST
WILL RESULT IN THE SCA WIND GUSTS.
WINDS WILL DIMINISH BELOW SCA LEVELS BY TUESDAY AS HIGH PRESSURE
BUILDS CLOSER.
RDG OF HIPRES AND SATD AMS THRU WED...WHICH WL INHIBIT WNDS FM
MIXING TO SFC. NO FLAGS XPCTD TIL LT THU...WHEN CFP CROSSES WATERS.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES ARE CURRENTLY RUNNING ABOUT ONE TO ONE AND ONE HALF
FEET ABOVE NORMAL THIS AFTERNOON. AS LOW PRESSURE TRACKS UP THE
MID-ATLANTIC COAST TONIGHT...A PERSISTENT ONSHORE FLOW WILL
CONTINUE...BRINGING MORE POSITIVE TIDAL ANOMALIES. HOWEVER...
ANOMALIES ARE NOT EXPECTED TO INCREASE MUCH TONIGHT WITH THE FLOW
TURNING MORE TOWARDS THE NORTH-NORTHEAST BEHIND THE SURFACE LOW.
LATEST CBOFS AS WELL AS EXTRA TROPICAL MODELS CONTINUE TO KEEP
WATER LEVELS JUST BELOW THRESHOLDS FOR MINOR COASTAL FLOODING.
WITH THE LUNAR CYCLE NEAR FIRST QUARTER...THE ASTRONOMICAL NORMS
ARE LOWER. WILL NOT ISSUE A COASTAL FLOOD ADVISORY FOR THOSE
REASONS...BUT WILL CONTINUE TO MONITOR THE TIDAL ANOMALIES THROUGH
TONIGHT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ531>534-537-
539>541-543.
SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR ANZ530-
538-542.
&&
$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...BJL
LONG TERM...HTS
AVIATION...BJL/HTS
MARINE...BJL/HTS
TIDES/COASTAL FLOODING...BJL
000
FXUS61 KLWX 231508
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1008 AM EST MON NOV 23 2009
.SYNOPSIS...
LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST THIS AFTERNOON AND
TOWARDS LONG ISLAND TONIGHT. HIGH PRESSURE WILL BUILD IN BEHIND THIS
SYSTEM TUESDAY AND TUESDAY NIGHT. A STORM SYSTEM WILL APPROACH FROM
THE NORTHWEST WEDNESDAY. A STRONGER SYSTEM WILL MOVE ACROSS THE AREA
THANKSGIVING AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CURRENT ANALYSIS SHOWS LOW PRESSURE OFF THE NORTH CAROLINA COAST
THIS MORNING. HIGH PRESSURE OVER EASTERN CANADA EXTENDS INTO NEW
ENGLAND. A SERIES OF WEAK UPPER-LEVEL DISTURBANCES EXTEND FROM NEW
JERSEY THROUGH THE MID-ATLANTIC AND INTO THE OHIO VALLEY.
THE SURFACE LOW OFF THE CAROLINA COAST WILL CONTINUE TO SLOWLY TRACK
UP THE MID-ATLANTIC COAST THIS AFTERNOON. WITH HIGH PRESSURE TO THE
NORTH...A LOW-LEVEL EASTERLY FLOW WILL USHER IN PLENTY OF MOISTURE
FROM THE ATLANTIC OCEAN. THE WARMER AND MORE MOIST AIR AT THE
LOW-LEVELS WILL OVERRUN THE COOL AIR AT THE SURFACE...RESULTING IN
PLENTY OF CLOUDS ALONG WITH PERIODS OF RAIN. WEAK MID-LEVEL FORCING
WILL KEEP THE STEADIEST RAIN ACROSS THE VIRGINIA PIEDMONT INTO LOWER
SOUTHERN MARYLAND...WHERE RAINFALL AMOUNTS AROUND ONE QUARTER TO ONE
HALF INCH ARE EXPECTED. FURTHER NORTH AND WEST...RAINFALL AMOUNTS
WILL BE CLOSER TO ONE TENTH OF AN INCH...WITH EVEN LIGHTER AMOUNTS
NEAR THE MASON DIXON LINE.
MAX TEMPERATURES THIS AFTERNOON WILL BE SEVERAL DEGREES COOLER
COMPARED TO RECENT DAYS DUE TO THE CLOUD COVER AND RAIN. MAX TEMPS
WILL 40S IN THE SHENANDOAH VALLEY TO THE LOWER 50S IN WASHINGTON AND
BALTIMORE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
TNGT THE LOW WL BE TRACKING NE OF THE AREA. WL HV CAT POPS IN THE
XTRM NE CORNER OF THE CWA FOR THE EVE HRS...DROPPING TO CHC
EVERYWHERE AFTR MDNGT. SKIES WL RMN CLDY. AGN LTL MODERATION W/
THE TEMPS - XPCT THE LOWS TNT TO RANGE FM A40 IN THE HIGHLANDS TO
A50 ALONG THE BAY.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
WEAK HIPRES WILL BUILD OVER THE AREA BEHIND THE DEPARTING LOW OFF
THE NEW ENGLAND COAST. DESPITE HIPRES OVRHD...CLDY CONDITIONS WILL
CONT MIDWEEK AS LLVL MOISTURE REMAINS TRAPPED BELOW SUBSIDENCE
INVERSION. CANNOT RULE OUT PATCHY DRIZZLE WITH LGT SLY FLOW AT LLVLS
SUPPORTING WEAK ISENTROPIC LIFT IN SHALLOW MOIST LAYER.
LEADING UPPER SHORTWAVE ENERGY EMBEDDED IN C CONUS LONGWAVE TROUGH
WILL TRACK OVER THE MIDWEST TUE AND THE GREAT LAKES WED. ALTHOUGH
THIS WEAKENING SYSTEM SHOULD TRACK WELL NW OF THE AREA...ENOUGH LIFT
AIDED BY DPVA/WAA WILL DEVELOP TO MENTION LOW CHANCES FOR SHOWERS
WED/WED NGT.
THE TRAILING SHORTWAVE TROUGH DROPS SEWD WHILE AMPLIFYING ACROSS THE
C CONUS THU. WITH STRENGTHENING HGT FALLS AHEAD OF THE CUTOFF
LOW...SFC DEVELOPMENT IS FCST TO OCCUR SOMEWHERE ALONG THE SE COAST.
BEST CWFA-WIDE CHANCE FOR RAIN OR SHOWERS APPEARS TO BE THU AFTN
INTO THU NGT WITH THE SFC LOW TRACKING THRU THE MID ATLANTIC REGION.
WITH THE THERMAL GRADIENT TIGHTENING...STRONG CAA WILL ENSUE BEHIND
THE SFC LOW ONCE THE ATTENDANT COLD FRONT CROSSES THE APPALACHIANS
LATE THU INTO FRI. 00Z GFS BUFKIT SOUNDINGS SUPPORT A RA/SN MIX FOR
THE HIGHER ELEVATIONS IN THE POTOMAC HIGHLANDS THU NGT AND FRI.
CYCLONIC WLY FLOW AROUND THE UPPER LOW WILL LEAD TO SEASONABLY COLD
TEMPERATURES ACROSS THE ENTIRE AREA WHILE PROLONGING THE CHANCES FOR
UPSLOPE SN SHOWERS ACROSS THE WRN SLOPES OF THE ALLEGHENY FRONT AND
POTOMAC HIGHLANDS THRU SAT. HIPRES BUILDS BACK INTO THE AREA SUN.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
LOW CLOUDS WILL CONTINUE TO AFFECT THE TERMINALS THROUGHOUT THE
AFTERNOON. RAIN WILL ALSO OVERSPREAD THE TERMINALS. MVFR CIGS ACROSS
MOST OF THE AIRPORTS THIS MORNING WILL DROP TO IFR LEVELS ONCE THE
RAIN BEGINS. MVFR/IFR VSBYS ARE ALSO EXPECTED IN AREAS OF RAIN. MORE
IFR CIGS ARE EXPECTED TONIGHT WITH MVFR/IFR VSBYS.
PERIODS OF SUB-VFR CIGS AND DZ POSSIBLE THRU MIDWEEK AS MARINE
MOISTURE REMAINS TRAPPED AT THE LLVLS. A STORM SYSTEM WILL TRACK NW
OF THE TERMINALS WED BUT CLOSE ENOUGH TO BRING CHANCES FOR SHRA. A
STRONGER DISTURBANCE IS EXPECTED TO MOVE THRU THU INTO ERY FRI.
&&
.MARINE...
WILL CONTINUE WITH A SMALL CRAFT ADVISORY THIS AFTERNOON FOR THE
CHESAPEAKE BAY AND LOWER TIDAL POTOMAC. THE PRESSURE GRADIENT WILL
STRENGTHEN A BIT RESULTING IN WIND GUSTS PAST SCA CRITERIA. ACROSS
THE UPPER TIDAL POTOMAC...WIND GUSTS AROUND 15 KNOTS ARE EXPECTED
THIS AFTERNOON. WINDS WILL TURN MORE TOWARD THE NORTH TONIGHT AS THE
LOW PRESSURE TRACKS TOWARD LONG ISLAND. MORE SCA WIND GUSTS ARE
EXPECTED ACROSS THE CHESAPEAKE BAY AND LOWER TIDAL POTOMAC.
WINDS WILL BE LGT DURING THE MIDDLE PART OF THE WEEK WITH HIPRES
OVRHD. THE PRESSURE GRADIENT WILL TIGHTEN LATE IN THE WEEK AS
DEVELOPING LOPRES TRACKS UP THE MID ATLANTIC COAST. SCA CONDITIONS
APPEARS POSSIBLE THU AFTN AND NGT AS THE LOW TRACKS OVER THE REGION.
STRONG CAA BEHIND THE LOW AND ASSOCIATED COLD FRONT WILL ALLOW FOR
WIDESPREAD SCA CONDITIONS TO CONT INTO THE FIRST HALF OF THE
WEEKEND.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES CURRENTLY ARE RUNNING ABOUT ONE HALF TO ONE FOOT
ABOVE NORMAL THIS MORNING. AS LOW PRESSURE TRACKS UP THE
MID-ATLANTIC COAST THIS AFTERNOON AND TOWARDS LONG ISLAND
TONIGHT...A PERSISTENT ONSHORE FLOW WILL CONTINUE. TIDAL ANOMALIES
MAY INCREASE AS THE LOW PRESSURE PASSES BY TO THE EAST LATE THIS
AFTERNOON INTO TONIGHT. LATEST CBOFS AS WELL AS EXTRA TROPICAL
MODELS CONTINUE TO KEEP WATER LEVELS BELOW THRESHOLDS FOR MINOR
COASTAL FLOODING. WILL CONTINUE TO MONITOR THE TIDAL ANOMALIES THIS
AFTERNOON...WITH MAX HIGH TIDE EXPECTED TONIGHT ANY INCREASE IN
TIDAL ANOMALIES MAY WARRANT A COASTAL FLOOD ADVISORY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ531>534-537-
539>541-543.
SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR ANZ530-
538-542.
&&
$$
PRODUCTS...LASORSA/WOODY!/JRK
000
FXUS61 KLWX 231059
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
559 AM EST MON NOV 23 2009
.SYNOPSIS...
LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST TODAY. THE LOW WILL
TRACK UP THE COAST AND SOUTHEAST OF LONG ISLAND TONIGHT. HIGH
PRESSURE WILL BUILD IN BEHIND THIS SYSTEM TUESDAY AND TUESDAY
NIGHT. A STORM SYSTEM WILL APPROACH FROM THE NORTHWEST WEDNESDAY.
A STRONGER SYSTEM WILL MOVE ACROSS THE AREA THANKSGIVING AND
FRIDAY.
&&
.NEAR TERM /TODAY/...
DID A QUICK UPDATE - TRAFFIC CAM ON AFTON MT SURE LOOKS LK SOME
WET SNOW AT THE EDGE OF THE RD...AND WINTERGREEN SKI AREA IS
34/34. CALLS TO EOC`S DID NOT REVEAL ANY SNOW REPS...BUT FOR NEXT
COUPLE OF HRS HV ADDED MENTION OF SNOW ABV 022 FT.
WITH HIGH PRES OVER NRN NEW ENGLAND AND MOISTURE TRACKING UP FM
THE SE MY FIRST IMPRESSION WAS "I`M GLAD IT`S NOT A LTL LATER IN
THE YR" OR ELSE I FEAR WE`D BE LOOKING AT A FZRA SITUATION. BUT
IT`S NOT COLD ENOUGH AT THE SFC FOR THAT TO BE A CONSIDERATION
TDA.
LOW PRES DVLPG OFF THE CAROLINA CST IS PUSHING MOISTURE INTO SRN
VA. THIS IS RUNNING INTO THE SFC HIGH...WHICH IN TURN IS SLOWING
THE NWD PROGRESSION.
MOISTURE WILL CONT TO WORK INTO THE CWA..AND BY THIS AFTN WE`LL HV
CAT POPS ACROSS THE ENTIRE AREA. HIGHEST QPF BTWN 1/4-1/2" E OF
I-95...ELSEWHERE UP TO 1/4". UNDER XTNSV CLD CVR AND NERLY WINDS
TEMPS WL DO LTL CLIMBING - RANGING FM THE M40S HIGHLANDS TO LM50S
ALONG THE BAY.
&&
.SHORT TERM / TUESDAY THROUGH 6 AM TUESDAY/...
TNGT THE LOW WL BE TRACKING NE OF THE AREA. WL HV CAT POPS IN THE
XTRM NE CORNER OF THE CWA FOR THE EVE HRS...DROPPING TO CHC
EVERYWHERE AFTR MDNGT. SKIES WL RMN CLDY. AGN LTL MODERATION W/
THE TEMPS - XPCT THE LOWS TNT TO RANGE FM A40 IN THE HIGHLANDS TO
A50 ALONG THE BAY.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
WEAK HIPRES WILL BUILD OVER THE AREA BEHIND THE DEPARTING LOW OFF
THE NEW ENGLAND COAST. DESPITE HIPRES OVRHD...CLDY CONDITIONS WILL
CONT MIDWEEK AS LLVL MOISTURE REMAINS TRAPPED BELOW SUBSIDENCE
INVERSION. CANNOT RULE OUT PATCHY DRIZZLE WITH LGT SLY FLOW AT LLVLS
SUPPORTING WEAK ISENTROPIC LIFT IN SHALLOW MOIST LAYER.
LEADING UPPER SHORTWAVE ENERGY EMBEDDED IN C CONUS LONGWAVE TROUGH
WILL TRACK OVER THE MIDWEST TUE AND THE GREAT LAKES WED. ALTHOUGH
THIS WEAKENING SYSTEM SHOULD TRACK WELL NW OF THE AREA...ENOUGH LIFT
AIDED BY DPVA/WAA WILL DEVELOP TO MENTION LOW CHANCES FOR SHOWERS
WED/WED NGT.
THE TRAILING SHORTWAVE TROUGH DROPS SEWD WHILE AMPLIFYING ACROSS THE
C CONUS THU. WITH STRENGTHENING HGT FALLS AHEAD OF THE CUTOFF
LOW...SFC DEVELOPMENT IS FCST TO OCCUR SOMEWHERE ALONG THE SE COAST.
BEST CWFA-WIDE CHANCE FOR RAIN OR SHOWERS APPEARS TO BE THU AFTN
INTO THU NGT WITH THE SFC LOW TRACKING THRU THE MID ATLANTIC REGION.
WITH THE THERMAL GRADIENT TIGHTENING...STRONG CAA WILL ENSUE BEHIND
THE SFC LOW ONCE THE ATTENDANT COLD FRONT CROSSES THE APPALACHIANS
LATE THU INTO FRI. 00Z GFS BUFKIT SOUNDINGS SUPPORT A RA/SN MIX FOR
THE HIGHER ELEVATIONS IN THE POTOMAC HIGHLANDS THU NGT AND FRI.
CYCLONIC WLY FLOW AROUND THE UPPER LOW WILL LEAD TO SEASONABLY COLD
TEMPERATURES ACROSS THE ENTIRE AREA WHILE PROLONGING THE CHANCES FOR
UPSLOPE SN SHOWERS ACROSS THE WRN SLOPES OF THE ALLEGHENY FRONT AND
POTOMAC HIGHLANDS THRU SAT. HIPRES BUILDS BACK INTO THE AREA SUN.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
CLDS HV BEEN INCRSG/LOWERING OVER THE PAST FEW HRS. AM XPCTG THE
CLDS TO CONTINUE TO LOWER THRU THE MRNG HRS AS THE LOW DVLPS OFF
THE NC CST...DROPPING INTO THE IFR RANGE AT MOST TAF SITES BY
SUNRISE AND THEN RMNG THRUT THE DAY AND INTO TNGT.
PERIODS OF SUB-VFR CIGS AND DZ POSSIBLE THRU MIDWEEK AS MARINE
MOISTURE REMAINS TRAPPED AT THE LLVLS. A STORM SYSTEM WILL TRACK NW
OF THE TERMINALS WED BUT CLOSE ENOUGH TO BRING CHANCES FOR SHRA. A
STRONGER DISTURBANCE IS EXPECTED TO MOVE THRU THU INTO ERY FRI.
&&
.MARINE...
WINDS ALREADY INTO MARGINAL SCA VALUES ON THE BAY AT 3 AM. AS THE
LOW DVLPS OFF THE CST THESE WL NO DOUBT CONT TDA AND TNGT OVR THE
BAY AND LOWER PART OF THE PTMC.
WINDS WILL BE LGT DURING THE MIDDLE PART OF THE WEEK WITH HIPRES
OVRHD. THE PRESSURE GRADIENT WILL TIGHTEN LATE IN THE WEEK AS
DEVELOPING LOPRES TRACKS UP THE MID ATLANTIC COAST. SCA CONDITIONS
APPEARS POSSIBLE THU AFTN AND NGT AS THE LOW TRACKS OVER THE REGION.
STRONG CAA BEHIND THE LOW AND ASSOCIATED COLD FRONT WILL ALLOW FOR
WIDESPREAD SCA CONDITIONS TO CONT INTO THE FIRST HALF OF THE
WEEKEND.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES RANGE FROM NEAR NORMAL TO ONE FOOT ABOVE NORMAL
TODAY AND TONIGHT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ531>534-537-
539>541-543.
SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR ANZ530-
538-542.
&&
$$
PRODUCTS...WOODY!/JRK
000
FXUS61 KLWX 230849
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
349 AM EST MON NOV 23 2009
.SYNOPSIS...
LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST TODAY. THE LOW WILL
TRACK UP THE COAST AND SOUTHEAST OF LONG ISLAND TONIGHT. HIGH
PRESSURE WILL BUILD IN BEHIND THIS SYSTEM TUESDAY AND TUESDAY
NIGHT. A STORM SYSTEM WILL APPROACH FROM THE NORTHWEST WEDNESDAY.
A STRONGER SYSTEM WILL MOVE ACROSS THE AREA THANKSGIVING AND
FRIDAY.
&&
.NEAR TERM /TODAY/...
WITH HIGH PRES OVER NRN NEW ENGLAND AND MOISTURE TRACKING UP FM
THE SE MY FIRST IMPRESSION WAS "I`M GLAD IT`S NOT A LTL LATER IN
THE YR" OR ELSE I FEAR WE`D BE LOOKING AT A FZRA SITUATION. BUT
IT`S NOT COLD ENOUGH AT THE SFC FOR THAT TO BE A CONSIDERATION TDA.
LOW PRES DVLPG OFF THE CAROLINA CST IS PUSHING MOISTURE INTO SRN
VA. THIS IS RUNNING INTO THE SFC HIGH...WHICH IN TURN IS SLOWING
THE NWD PROGRESSION. AS MENTIONED ABV - TEMPS ARE IN LM40S SO NO
FZRA WORRIES TDA. DWPTS ARE WELL ABV FRZG AS WELL SO NO EVAP
COOLING CONCERNS.
MOISTURE WILL CONT TO WORK INTO THE CWA..AND BY THIS AFTN WE`LL HV
CAT POPS ACROSS THE ENTIRE AREA. HIGHEST QPF BTWN 1/4-1/2" E OF
I-95...ELSEWHERE UP TO 1/4". UNDER XTNSV CLD CVR AND NERLY WINDS
TEMPS WL DO LTL CLIMBING - RANGING FM THE M40S HIGHLANDS TO LM50S
ALONG THE BAY.
&&
.SHORT TERM /TONIGHT/...
TNGT THE LOW WL BE TRACKING NE OF THE AREA. WL HV CAT POPS IN THE
XTRM NE CORNER OF THE CWA FOR THE EVE HRS...DROPPING TO CHC
EVERYWHERE AFTR MDNGT. SKIES WL RMN CLDY. AGN LTL MODERATION W/
THE TEMPS - XPCT THE LOWS TNT TO RANGE FM A40 IN THE HIGHLANDS TO
A50 ALONG THE BAY.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
WEAK HIPRES WILL BUILD OVER THE AREA BEHIND THE DEPARTING LOW OFF
THE NEW ENGLAND COAST. DESPITE HIPRES OVRHD...CLDY CONDITIONS WILL
CONT MIDWEEK AS LLVL MOISTURE REMAINS TRAPPED BELOW SUBSIDENCE
INVERSION. CANNOT RULE OUT PATCHY DRIZZLE WITH LGT SLY FLOW AT LLVLS
SUPPORTING WEAK ISENTROPIC LIFT IN SHALLOW MOIST LAYER.
LEADING UPPER SHORTWAVE ENERGY EMBEDDED IN C CONUS LONGWAVE TROUGH
WILL TRACK OVER THE MIDWEST TUE AND THE GREAT LAKES WED. ALTHOUGH
THIS WEAKENING SYSTEM SHOULD TRACK WELL NW OF THE AREA...ENOUGH LIFT
AIDED BY DPVA/WAA WILL DEVELOP TO MENTION LOW CHANCES FOR SHOWERS
WED/WED NGT.
THE TRAILING SHORTWAVE TROUGH DROPS SEWD WHILE AMPLIFYING ACROSS THE
C CONUS THU. WITH STRENGTHENING HGT FALLS AHEAD OF THE CUTOFF
LOW...SFC DEVELOPMENT IS FCST TO OCCUR SOMEWHERE ALONG THE SE COAST.
BEST CWFA-WIDE CHANCE FOR RAIN OR SHOWERS APPEARS TO BE THU AFTN
INTO THU NGT WITH THE SFC LOW TRACKING THRU THE MID ATLANTIC REGION.
WITH THE THERMAL GRADIENT TIGHTENING...STRONG CAA WILL ENSUE BEHIND
THE SFC LOW ONCE THE ATTENDANT COLD FRONT CROSSES THE APPALACHIANS
LATE THU INTO FRI. 00Z GFS BUFKIT SOUNDINGS SUPPORT A RA/SN MIX FOR
THE HIGHER ELEVATIONS IN THE POTOMAC HIGHLANDS THU NGT AND FRI.
CYCLONIC WLY FLOW AROUND THE UPPER LOW WILL LEAD TO SEASONABLY COLD
TEMPERATURES ACROSS THE ENTIRE AREA WHILE PROLONGING THE CHANCES FOR
UPSLOPE SN SHOWERS ACROSS THE WRN SLOPES OF THE ALLEGHENY FRONT AND
POTOMAC HIGHLANDS THRU SAT. HIPRES BUILDS BACK INTO THE AREA SUN.
&&
.AVIATION /TODAY THROUGH FRIDAY/...
CLDS HV BEEN INCRSG/LOWERING OVER THE PAST FEW HRS. AM XPCTG THE
CLDS TO CONTINUE TO LOWER THRU THE MRNG HRS AS THE LOW DVLPS OFF
THE NC CST...DROPPING INTO THE IFR RANGE AT MOST TAF SITES BY
SUNRISE AND THEN RMNG THRUT THE DAY AND INTO TNGT.
PERIODS OF SUB-VFR CIGS AND DZ POSSIBLE THRU MIDWEEK AS MARINE
MOISTURE REMAINS TRAPPED AT THE LLVLS. A STORM SYSTEM WILL TRACK NW
OF THE TERMINALS WED BUT CLOSE ENOUGH TO BRING CHANCES FOR SHRA. A
STRONGER DISTURBANCE IS EXPECTED TO MOVE THRU THU INTO ERY FRI.
&&
.MARINE...
WINDS ALREADY INTO MARGINAL SCA VALUES ON THE BAY AT 3 AM. AS THE
LOW DVLPS OFF THE CST THESE WL NO DOUBT CONT TDA AND TNGT OVR THE
BAY AND LOWER PART OF THE PTMC.
WINDS WILL BE LGT DURING THE MIDDLE PART OF THE WEEK WITH HIPRES
OVRHD. THE PRESSURE GRADIENT WILL TIGHTEN LATE IN THE WEEK AS
DEVELOPING LOPRES TRACKS UP THE MID ATLANTIC COAST. SCA CONDITIONS
APPEARS POSSIBLE THU AFTN AND NGT AS THE LOW TRACKS OVER THE REGION.
STRONG CAA BEHIND THE LOW AND ASSOCIATED COLD FRONT WILL ALLOW FOR
WIDESPREAD SCA CONDITIONS TO CONT INTO THE FIRST HALF OF THE
WEEKEND.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES RANGE FROM NEAR NORMAL TO ONE FOOT ABOVE NORMAL
TODAY AND TONIGHT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ531>534-537-
539>541-543.
SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR ANZ530-
538-542.
&&
$$
PRODUCTS...WOODY!/JRK
000
FXUS61 KLWX 230216 AAB
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
916 PM EST SUN NOV 22 2009
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO RETREAT TO THE NORTH TONIGHT WHILE AN
AREA OF LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST. THIS LOW WILL
TRACK UP THE MID-ATLANTIC COAST MONDAY AND TOWARDS NEW ENGLAND
MONDAY NIGHT INTO TUESDAY. HIGH PRESSURE WILL BUILD IN BEHIND THIS
SYSTEM LATER TUESDAY AND WEDNESDAY. A COLD FRONT WILL PASS THROUGH
THURSDAY BRINGING UNSETTLED CONDITIONS. AN UPPER-LEVEL LOW WILL
CONTINUE TO IMPACT THE REGION LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
OVERALL SYNOPTIC EVOLUTION STILL ON TRACK FROM PREV FCST.
ISENTROPIC LIFT INCRS TNGT...WITH LOW-LVL CLD CVR XPCD TO SPREAD
ACRS FCST AREA LATE. RAIN WILL CONT TO SPREAD NWD AS MID-LVL
SHRTWV TROF APRCHS...BUT WILL ONLY ENCROACH UPON SRN ZONES THRU
TNGT. MODEL TRENDS HAVE BEEN TO SLOW ARRIVAL OF PCPN...AND THIS
TREND WAS FOLLOWED FOR THE EVE UPDATE. HAVE TRIMMED NRN EDGE OF
POPS DOWNWARD THRU TNGT. PREV DISCUSSION FOLLOWS...
CURRENT ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER NEW ENGLAND THIS
AFTERNOON. A SURFACE LOW CONTINUES TO TRACK ALONG THE GULF COAST
STATES. THE UPPER-LEVEL LOW ASSOCIATED WITH THE SURFACE LOW IS
TRACKING TOWARD THE TENNESSEE VALLEY.
SURFACE HIGH WILL CONTINUE TO RETREAT TO THE NORTHEAST TONIGHT WHILE
THE SURFACE LOW REDEVELOPS ALONG THE SOUTHEAST COAST. THE
UPPER-LEVEL LOW ASSOCIATED WITH THIS SYSTEM WILL TRACK THROUGH THE
TENNESSEE VALLEY TONIGHT AND TOWARD SOUTHWESTERN VIRGINIA BY MONDAY
MORNING.
A LOW-LEVEL EAST-SOUTHEAST FLOW AROUND THE DEPARTING HIGH AND THE
LOW PRESSURE SYSTEM WILL BRING INCREASING AMOUNTS OF MOISTURE OFF
THE ATLANTIC OCEAN. THE MOISTURE INCREASE COMBINED WITH ISENTROPIC
LIFT WILL RESULT IN INCREASING LOW CLOUDS LATER THIS EVENING INTO
THE OVERNIGHT HOURS. WITH THE ACTUAL STORM SYSTEM REMAINING WELL TO
THE SOUTH...DRY CONDITIONS ARE EXPECTED THROUGH THIS EVENING.
HOWEVER...RAIN AHEAD OF THE STORM SYSTEM WILL BEGIN TO OVERSPREAD
THE REGION FROM SOUTH TO NORTH LATE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
RAIN WILL SPREAD NWD THRU FCST AREA DURG MID-LATE MRNG.
CATEGORICAL POPS LOOK REASONABLE STILL FOR TMW AFTN AND WERE
RETAINED...ALTHO IT APPEARS THAT ACCUMULATIONS WILL BE SLGTLY
HIGHER WITH EWD EXTENT CLOSER TO XPCD PATH OF SHRTWV TROF. PREV
DISCUSSION FOLLOWS...
THE SURFACE LOW WILL CONTINUE TO TRACK UP THE MID-
ATLANTIC COAST WHILE THE UPPER-LEVEL LOW SHEARS APART AS IT TRACKS
ACROSS OUR REGION. A LOW-LEVEL EASTERLY FLOW COMBINED WITH
ISENTROPIC LIFT WILL RESULT IN LOW CLOUDS ALONG WITH OCCASIONAL
RAIN. RAINFALL AMOUNTS SHOULD BE ON THE LIGHT SIDE DUE TO THE LACK
OF STRONG DYNAMICS WITH THIS SYSTEM. MAX TEMPS WILL BE SEVERAL
DEGREES COOLER THAN RECENT DAYS DUE TO THE RAINFALL...RANGING FROM
THE MID AND UPPER 40S ACROSS THE POTOMAC HIGHLANDS INTO THE
SHENANDOAH VALLEY...TO NEAR 50 IN WASHINGTON AND BALTIMORE...TO
THE LOWER AND MIDDLE 50S ACROSS LOWER SOUTHERN MARYLAND.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
ANY PCPN LINGERING MON NGT WUD BE AS A RSLT OF THE DEF AXIS ACRS
CWFA. HWVR...LOPRES RATHER WEAK...AND FAR OFFSHORE...SO DONT THINK
THAT PCPN WUD BE PLENTIFUL. WUD BE MORE CONCERNED ABT DZ...BUT SFC
WNDS NLY NOT NE/ELY.
HIPRES BRIEFLY BLDS TUE-TUE NGT. BUT IT SHUD BE A DIRTY RDG AS AMPLE
LLVL MSTR STILL LINGERS. SUNSHN SHUD BE LMTD...ASSUMING IT CAN BRK
THRU MARINE STRATUS. BASED ON TKNS OF MARINE DECK ON MDL
TIME-HGTS...THAT/LL BE A BIG ASSUMPTION. SUSPECT LLVL CLDS WL BE
SUFFICIENT FOR DZ TO DVLP TUE NGT...SPCLY SINCE SFC HIGH WEDGED A LA
CAD AND H9-8 FLOW BCMG SLY.
CMPLX SCENARIO SETTING UP FOR MID WK...AS S/WV ENERGY DROPS INTO
CNTRL PLAINS...CUTTING OFF H5 LOW BY TUE. ADDTL VORTS CARVE OUT A
2ND LOW...WHICH WL DEEPEN LOW OVR GRTLKS BY THU. LCLLY...CWFA WL
RECEIVE ISENT LIFT...THEN GLANCING BLOW OF PVA WED. THUS...CLDS
GOING NOWHERE...AND CHC SHRA RETURNS. SOME MIXING CUD PUNCH HOLES IN
THE CLD DECK BHD VORT LT WED-WED NGT.
TEMPS FAIRLY TEMPERATE THRU THE PD. NOT MUCH SPREAD IN MOS TEMPS
TMRW NGT-TUE...AND A SLGTLY LRGR SPREAD TUE NGT. CONSIDERING
CLDS...STAYED AWAY FM BIG DIURNAL SWINGS-- WARM SIDE OF MEAN FOR
MIN-T BUT COOLER SIDE FOR MAXT.
XTNDD...DP H5 TROF AXIS/CUTOFF LOW TO PIVOT ACRS CWFA THU-FRI. THIS
CYCLE...GDNC - SPCLY GFS - NOW TRANSFERRING ENERGY TO DVLPG CSTL
SYSTM LT THU NGT-ELY FRI MRNG. BUT EVEN THE MORE STBL ECMWF TRENDING
TWD GFS. EITHER WAY THE END RSLT WL BE SIMLR...FVRBL SUPPORT FOR
PCPN...AND SIGNALS THAT HIER ELEVS CUD RECEIVE SNW. WL INCR POPS
THU-THU NGT...AND STICK W/ MTN SNW/MIX ONCE CAA UPON US THU PM. NW
FLOW PTTN THRU SAT. WL ENHANCE UPSPL PCPN THRU THAT TIME.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
CIGS AOB 1.0 KFT XPCD TNGT AS ISENTROPIC LIFT INCRS ACRS RGN.
VSBYS ALSO XPCD TO DROP TO IFR-MVFR THRESHOLDS AS FOG DVLPS THIS
EVE. ONSET OF DRZL XPCD LATE TNGT...WITH RAIN MOVG NWD INTO SRN
PORTIONS OF FCST AREA BY 08-10 UTC. DRZL CONTS ACRS NRN TERMINALS
THRU MRNG UNTIL RAIN ARRIVES AT ALL TERMINALS DURG LATE MRNG.
RESTRICTIONS XPCD TO CONT THRU AT LEAST MON EVE.
FLGT RESTRICTIONS PSBL THRU MUCH OF WK AS UNSTTLD CONDS ABOUND. IF
THERE WERE A BRK IT WUD COME TUE AFTN/EVE...BUT LOW CLDS/DZ LKLY TO
RTN TUE NGT.
&&
.MARINE...
PRESSURE GRADIENT APPEARS TO BE SHARPENING SLGTLY EARLIER THAN
DEPICTED IN PREV GRIDS...MAINLY LWR PORTIONS OF MD CHSPK BAY AND
LWR TIDAL POTOMAC. HAVE ADJUSTED START TIME OF SMALL CRAFT ADZY TO
PRESENT TIME FOR THESE ZONES..WHERE 17-20 KT GUSTS COMMON AND XPCD
TO PERSIST. RMNDR OF ADZY WILL BGN AT MIDNIGHT AS PREVLY ISSUED.
PREV DISCUSSION FOLLOWS...
LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST COAST TONIGHT. A
STRENGTHENING PRESSURE GRADIENT DUE TO THE LOW WILL BRING SCA WIND
GUSTS ACROSS THE CHESAPEAKE BAY AND LOWER TIDAL POTOMAC OVERNIGHT.
AS LOW PRESSURE TRACKS UP THE MID- ATLANTIC COAST MONDAY...MORE
SCA CONDITIONS ARE EXPECTED ACROSS THE LOWER TIDAL POTOMAC AND
CHESAPEAKE BAY. HAVE CAPPED WIND GUSTS MONDAY AROUND 15 KNOTS
ACROSS THE UPPER TIDAL POTOMAC...BUT WITH FASTER WINDS LESS THAN A
THOUSAND FEET FROM THE SURFACE...ANY MIXING WOULD BRING STRONGER
WIND GUSTS LATER MONDAY MORNING/AFTERNOON. THIS WILL HAVE TO BE
MONITORED BY LATER SHIFTS.
G20KT LKLY TO CONT INTO TMRW NGT DUE TO NLY FLOW...SPCLY FOR MAIN
CHANNEL BAY BLO POOLES ISL AND FOR LWR PTMC. WL INCL BIG INLETS BUT
NOT BALT HARBOR/PAX RIVER. HIPRES RDG SHUD DECR WNDS TUE-WED...ALTHO
LOW CLDS SHUD BE PLENTIFUL AND RA A PSBLTY BY WED.
&&
.TIDES/COASTAL FLOODING...
WITH HIGH PRESSURE WELL TO OUR NORTH...AN ONSHORE FLOW HAS DEVELOPED
THIS AFTERNOON. THE FLOW IS WEAK AND TIDAL ANOMALIES RANGE FROM NEAR
NORMAL TO ABOUT ONE HALF FOOT ABOVE NORMAL. LOW PRESSURE IS EXPECTED
TO DEVELOP OFF THE SOUTHEAST COAST TONIGHT AND THE GRADIENT IS
EXPECTED TO TIGHTEN BETWEEN THESE TWO SYSTEMS OVERNIGHT AND MONDAY.
AS THE LOW TRACKS UP THE MID-ATLANTIC COAST MONDAY INTO MONDAY
NIGHT...THIS WILL CAUSE TIDAL ANOMALIES TO INCREASE DURING THIS
TIME. LATEST CBOFS AND EXTRATROPICAL MODELS CONTINUE TO INDICATE
THAT WATER LEVELS WILL REMAIN BELOW THRESHOLDS FOR MINOR COASTAL
FLOODING. THE ASTRONOMICAL NORMS FOR WATER LEVELS ARE ALSO ON THE
LOWER SIDE DUE TO THE LUNAR CYCLE APPROACHING THE FIRST QUARTER
PHASE. HAVE NOT ISSUED AN ADVISORY FOR THESE TWO REASONS...BUT THIS
WILL HAVE TO BE MONITORED BY LATER SHIFTS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 5 AM EST TUESDAY
FOR ANZ531>533-539>541.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 8 PM EST MONDAY
FOR ANZ530-538-542.
SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ534-537-543.
&&
$$
UPDATE...KRAMAR
PREV DISCUSSION...KRAMAR/LASORSA/HTS
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