National Weather Service United States Department of Commerce

 


000
FXUS62 KILM 271152
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
752 AM EST TUE JAN 27 2015

.SYNOPSIS...
STRONG LOW PRESSURE SOUTH OF NEW ENGLAND WILL CONTINUE TO SLOWLY
MOVE NORTH AS HIGH PRESSURE SLOWLY BUILDS INTO THE CAROLINAS THROUGH
THURSDAY. A COLD FRONT WILL MOVE ACROSS THE EASTERN CAROLINAS
THURSDAY NIGHT. MOISTURE SHOULD START FLOWING BACK INTO THE REGION
ON SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM TUESDAY...LIGHT RAIN AND PATCHY DRIZZLE WAS FALLING
ACROSS THE CAPE FEAR AREA AND THIS PRECIPITATION IS EXPECTED TO
PIVOT OFFSHORE THIS MORNING. THE COLUMN HAS SUFFICIENTLY DRIED OUT
IN THE DENDRITIC GROWTH ZONE MAKING THE PROSPECTS FOR ANY MIX WITH
FLURRIES ACROSS PENDER COUNTY REMOTE AS THE LIGHT PRECIPITATION
COMES TO AN END. SKIES HAVE FOR THE TIME BEING PARTIALLY CLEARED
FROM DILLON TO MYR AND WESTWARD.

WE WILL CONTINUE TO BE UNDER THE INFLUENCE OF A LONGWAVE TROUGH THIS
PERIOD AS IT VERY SLOWLY LIFTS NE THROUGH MID WEEK. SHORTWAVE ENERGY
WILL CONTINUE TO ROTATE AROUND THIS TROUGH. THE LAST OF THE
SIGNIFICANT MID-LEVEL SHORTWAVE TROUGHS TO EFFECT THE EASTERN
CAROLINAS WILL MOVE ACROSS THE AREA WED MORNING. EXAMINATION OF
MOISTURE PROFILES AND MODEL SOUNDINGS SHOW THE COLUMN WILL UNDERGO
SIGNIFICANT DRYING AND COOLING THIS PERIOD. THIS TREND IS ALREADY
UNDERWAY ACROSS OUR SOUTHERN AND WESTERN ZONES WITH PARTIAL CLEARING
UNDERWAY IN STRENGTHENING SUBSIDENT FLOW FROM BBP TO GGE WESTWARD.
HOWEVER...THIS TREND WILL BE SLOW TO PROGRESS ACROSS THE REMAINDER
OF THE FORECAST AREA GIVEN THE VERY LARGE AND STRONG NEGATIVELY
TILTED STORM SYSTEM SOUTH OF NEW ENGLAND WHICH WILL BE SLOW TO MOVE
N GIVEN IT HAS BEEN CAPTURED BY AN UPPER LOW. CLOUDS SHOULD BE
DECREASING ACROSS LUMBERTON AND THE GRAND STRAND THIS MORNING AND
THEN ACROSS EYF AND ILM BY/DURING THE AFTERNOON. HOWEVER...DO NOT
EXPECT A FULLY SUNNY DAY ANYWHERE AS CLOUDS WILL AT LEAST PARTIALLY
FILL IN AS UPSTREAM MID-LEVEL SHORTWAVE APPROACHES.

COLD AND DRY ADVECTION WILL DROP PRECIPITABLE WATER VALUES TO UNDER
ONE-QUARTER OF AN INCH TODAY. 850 MB TEMPS WILL DROP TO MINUS 4 TO
MINUS 6 DEG C. 500 MB TEMPS WILL DROP TO AROUND MINUS 30 DEG C.
EVEN WITH PARTIAL SUNSHINE...TEMPS WILL STRUGGLE TO GAIN UPWARD
MOMENTUM. IN FACT...WE EXPECT TEMPS TO STILL BE DROPPING THROUGH THE
FIRST PART OF THE MORNING IN SOME AREAS. HIGH TEMPS THIS AFTERNOON
WILL RECOVER INTO THE MID AND UPPER 40S...NORMAL FOR LATE JAN IS MID
AND UPPER 50S.

TONIGHT...EXPECT SKIES TO BE MAINLY CLEAR. WILL HAVE TO WATCH CLOUDS
SNEAKING DOWN THE COAST AROUND THE PERIPHERY OF A LARGE STORM SYSTEM
ACROSS NEW ENGLAND...HOWEVER AT THIS TIME...EXPECT THESE CLOUDS WILL
BE ROTATING BY TO OUR N AND NE AFTER DARK. TONIGHT...WE ARE
EXPECTING THE COLDEST NIGHT SINCE JAN 11TH. LOWS SHOULD BOTTOM OUT
AROUND SUNRISE WED IN THE MID AND UPPER 20S...LOWER 30S AT THE
BEACHES. A SURGE OF COLD AND DRY AIR OVERNIGHT SHOULD KEEP WINDS
FROM FULLY DECOUPLING...THUS LIMITING THE RADIATIONAL COOLING
COMPONENT. WAKE UP WIND CHILL VALUES FOR MOST OF US WED MORNING WILL
BE IN THE UPPER TEENS AND LOWER 20S. DEWPOINTS WILL FALL OUT OF THE
20S AND INTO THE TEENS TONIGHT.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...FINAL MID LEVEL IMPULSE ALREADY JUST OFFSHORE
BY THE START OF THE PERIOD WHILE SURFACE HIGH BUILDS INTO THE
COASTAL PLAIN BY AFTERNOON/EVENING. A CHILLY DAY WITH A BIT OF A
BREEZE TO START BUT WINDS WILL DECREASE AS THE DAY WEARS ON DUE TO
THE EASING PRESSURE GRADIENT. SKY SHOULD BE MOSTLY CLEAR AND THE
SENSE OF LOW LEVEL TEMPERATURE ADVECTION REMAINS COLD THROUGH THE
FIRST HALF OF THE NIGHT BEFORE WEAKLY REVERSING IN THE BACKING WIND
FIELD JUST OFF THE SURFACE. DAYTIME HIGHS ONLY IN THE 40S WILL
QUICKLY FALL WITH SUNSET DUE TO THE CLEAR SKIES AND LIGHT WINDS
THROUGH THE 30S AND SETTLE INTO MID 20S FOR LOWS CLOSE TO DAYBREAK.
THIS IS COOLER THAN PREVIOUSLY FORECAST AS RAD COOLING CONDITIONS
APPEAR BETTER IF NOT OPTIMIZED. PROGRESSION OF HIGH OFF THE COAST
PAIRED WITH THE APPROACH OF ANOTHER COOL FRONT SHOULD BOOST THURSDAY
TEMPS TO JUST SHY OF CLIMO AND CLOUDS MAY INCREASE SLOWLY. SURFACE
COOL FRONT MOVES THROUGH LATE THURSDAY NIGHT BUT THE UPPER LEVEL
ENERGY TRAILS CONSIDERABLY. THE DISCONNECTION BETWEEN THE TWO
PROBABLY PRECLUDES MEANINGFUL RAIN CHANCES.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...COOL ADVECTION ON FRIDAY MAY BE DELAYED A BIT
AS THE MAIN UPPER TROUGH AXIS SWINGS THROUGH BY EVENING OR
THEREAFTER. TOUGH TO SAY WHETHER MOS HIGHS TOO HIGH OR THAT TEMPS
MAY BEGIN FALLING IN THE AFTERNOON. FOR NOW WILL LEAVE INHERITED
HIGHS JUST SHY OF CLIMO. CHILLY AIRMASS SIMILAR TO WEDNESDAY`S
SETTLES IN FOR SATURDAY. SUNDAY STILL COOL BUT WITH OVERRUNNING
MOISTURE LEADING TO INCREASING CLOUDS AND PERHAPS SOME RAIN
SPREADING WEST TO EAST ACROSS THE AREA. THIS MOISTURE MAY BE WRUNG
OUT BY A COLD FRONT THAT SWEEPS THROUGH LATE MONDAY FOLLOWED BY SOME
MORE CHILLY BUT NOT ARTIC AIR. MEANWHILE INTERESTING SOUTHERN BRANCH
FEATURE HANGING BACK JUST WEST OF TEXAS.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 12Z...SATELLITE SHOWS WRAP AROUND STRATOCU THAT WILL AFFECT
LBT AND ILM FOR THE NEXT COUPLE OF HOURS...VFR CEILINGS
PREDOMINATELY. STRONG LOW PRESSURE DISHING IT OUT TO THE
NORTHEASTERN US WILL SLOWLY PULL OFF TO THE NORTHEAST. WE WILL SEE A
GUSTY NORTHWEST GRADIENT TODAY AS A RESULT...WITH GUSTS TO 20 KTS A
REASONABLE BET. WINDS LIGHTEN DIURNALLY THIS EVENING WITH NEARLY
CLEAR SKIES.

EXTENDED OUTLOOK...VFR WILL PREVAIL TUE THROUGH SAT.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM TUESDAY...SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED
FOR MUCH OF THE DAY. THESE CONDITIONS MAY PERSIST INTO TONIGHT FOR
PORTIONS OF THE WATERS. THE WATERS WILL BE UNDER THE PERIPHERAL
INFLUENCE OF A STRONG AREA OF LOW PRESSURE S OF NEW ENGLAND...MOVING
VERY SLOWLY TO THE N THROUGH THE PERIOD. AS A CONSEQUENCE...THE
PRESSURE GRADIENT WILL BE SLOW TO RELAX. IN FACT...THE GRADIENT MAY
TIGHTEN MORE SIGNIFICANTLY FOR A TIME OVERNIGHT AS A COLD/DRY SURGE
MOVES OUT ACROSS THE WATERS. ALSO...BACKSWELL FROM THIS LARGE STORM
SYSTEM WILL IMPACT THE WATERS...KEEPING SEAS ELEVATED EVEN WITH THE
STRONG OFFSHORE WIND COMPONENT. WIND SPEEDS THIS PERIOD WILL BE UP
TO 20 TO 25 KT. SEAS WILL BE UP TO 4 TO 6 FT WITHIN 20 NM...HIGHER
OFFSHORE. THE WIND DIRECTION WILL BE FROM THE NW...VEERING TO NNW
OVERNIGHT.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...WEDNESDAY BRINGS AN INITIALLY MODERATE
PRESSURE GRADIENT THAT WILL GRADUALLY EASE AS THE DAY WEARS ON.
NORTHERLY WINDS WILL SLOWLY ABATE AS HIGH PRESSURE BUILDS IN FROM
THE NORTHWEST. EVEN WITH THE EARLY DAY HIGHER WIND SPEEDS NO FLAGS
EXPECTED DUE TO THE OFFSHORE FLOW KEEPING THE LARGEST SEAS REMOVED
FROM THE COASTLINE. AS THE HIGH MOVES OVERHEAD AND EVENTUALLY OFF
THE COAST LATE THURSDAY A FURTHER DECREASE IN WIND SPEED EXPECTED
WHILE CONSIDERABLE VEERING IN DIRECTION OCCURS. SEAS SETTLE IN
HEIGHT EVEN IF THE PERIOD SHORTENS SLIGHTLY. SOUTHWESTERLY FLOW
PICKS UP THURSDAY NIGHT WITH APPROACH OF A COLD FRONT THAT SHOULD
CROSS THE REGION LATE IN THE PERIOD.

LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 AM TUESDAY...COOL AIR PUSH ON FRIDAY SHOULD KEEP
CONDITIONS BELOW ADVISORY OR HEADLINES THRESHOLDS WITH NWRLY FLOW
VEERING SLIGHTLY TO NE ON SEERN PERIPHERY OF LARGE HIGH OVER SRN
GREAT LAKES. THE LARGE ANTICYCLONE WILL BE SLOW TO PROGRESS EASTWARD
ON SATURDAY LEADING TO ONLY A MINOR ADDITIONAL VEER LOCALLY.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
AMZ250-252-254-256.

&&

$$

NEAR TERM...RJD
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43