FXUS62 KILM 260546
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1230 AM EST THU NOV 26 2009
.SYNOPSIS...
LOW PRESSURE OFFSHORE OF THE CAROLINAS OVERNIGHT...WILL MOVE
NORTHEAST AND AWAY FROM THE AREA TODAY...THANKSGIVING DAY. A STRONG
COLD FRONT WILL CROSS THE REGION LATE THURSDAY NIGHT...USHERING IN
DRY AND CHILLY AIR INTO THE WEEKEND. TEMPERATURES WILL REBOUND
SUNDAY AND MONDAY AS HIGH PRESSURE MOVES OFFSHORE. A COLD FRONT WILL
SWEEP ACROSS THE CAROLINAS TUESDAY BRINGING A CHANCE OF SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1215 AM TURKEY DAY...DECIDED TO RAISE A DENSE FOG ADVISORY
FOR THE INLAND COUNTIES...MAINLY ALONG AND WEST OF I-95 WHERE AREA
WILL BE SUBJECT TO THINNED CLOUDINESS...A SFC BASED INVERSION
KEEPING A DECOUPLED WIND REGIME ACROSS THE AREA AND PLENTY OF
TRAPPED LOW LEVEL MOISTURE WITHIN THIS LOW LEVEL INVERSION FOR THE
FOG. MIXING AROUND OR 1-2 HRS AFTER SUNRISE SHOULD
DISPERSE/DISSIPATE THE FOG. WILL HAVE TO MONITOR THE EASTERNMOST
COUNTIES ACROSS THE ILM CWA FOR POSSIBLE WIDESPREAD DENSE FOG WITH
MORE ATTETION PAID TO THE BACKEDGE OF THE MID-LEVEL AND HIGH LEVELS
CLOUDS TO WHERE THE FOG IS AT ITS WORST.
PREVIOUS DISCUSSION................................................
RAIN HAS COME TO AN END OVER LAND TONIGHT. CLOUDS SHOULD BEGIN
CLEARING OUT BETWEEN 06Z AND 12Z. MIN TEMPERATURES IN THE 40 TO 45
DEGREE RANGE LOOK TO BE ON TRACK. OBSERVATIONS INDICATE PATCHY FOG
ACROSS THE AREA SO WILL CONTINUE IN THE FORECAST. WIDESPREAD DENSE
FOG IS NOT EXPECTED THOUGH AS LOW PRESSURE INTENSIFIES AND WINDS
INCREASE A LITTLE OVERNIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 240 PM WEDNESDAY...DAYBREAK ON THANKSGIVING WILL FEATURE A
SURFACE LOW POSITIONED ROUGHLY 200 MILES OFFSHORE OF THE SC COAST
MOVING NNE. THIS SYSTEM WILL MOVE EAST OF VIRGINIA BEACH BY EARLY
THANKSGIVING EVE. CONSENSUS OF MODEL OUTPUT INDICATES ALL OF THE
RAIN ASSOCIATED WITH THIS SYSTEM WILL REMAIN WELL OFFSHORE
THURSDAY...BARELY INFLUENCING EVEN WINDS OVER THE AREA IN VERY LIGHT
NW FLOW. THUS WOULD EXPECT SUNSHINE TO MAKE A DEBUT TOMORROW WITH
AFTERNOON CUMULUS AS A COOL POOL ALOFT/TROUGH APPROACHES. HAVE
INTRODUCED ISOLATED SHOWERS THU EVENING AS THE NEGATIVELY TILTED
UPPER TROUGH AXIS CROSSES THE AREA BUT OVERALL THE COLUMN WILL
ALREADY BE FAIRLY DRY SO NOT EXPECTING VERY MUCH AT ALL IN THE WAY
OF QPF.
THE SHARP TROUGH WILL BRING AN ABRUPT CHANGE OF AIR MASS MORE TYPICAL
OF WINTER FRIDAY INTO SATURDAY. HAVE EVEN INTRODUCED PATCHY FROST
LATE FRIDAY INTO EARLY SATURDAY. FRIDAY MORNING WILL BE CHILLY BUT
THINK ENOUGH WIND WILL BE PRESENT IN THE BOUNDARY LAYER TO WARD OF
FROST DEVELOPMENT. LESS CLOUD COVER IN THE DAYS AHEAD BUT AT THE
EXPENSE OF SEASONABLY CHILLY AIR RUNNING 6-8 DEGREES BELOW NORMAL
READINGS FOR LATE NOVEMBER.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 240 PM WEDNESDAY...FAIRLY HIGH CONFIDENCE FORECAST FOR THE
FIRST PART OF THE EXTENDED WHICH WILL FEATURE PROGRESSIVE SURFACE
HIGH PRESSURE MOVING ACROSS UNDER A RELAXING MID LEVEL FLOW.
CONTINUED TO ADVERTISE A GRADUAL WARMING TREND FROM SATURDAY
THROUGH MONDAY AS THE HIGH MOVES OFFSHORE WITH A RETURN FLOW IN
FULL FORCE BY MONDAY. DRY CONDITIONS THROUGHOUT OF COURSE.
AN INTERESTING TURN OF EVENTS WITH THE LATEST OPERATIONAL GFS AS IT
IS NOW ADVERTISING TWO SEPARATE SYSTEMS FOR NEXT WEEK WITHOUT THE
PHASING. THE FIRST SYSTEM MOVES ACROSS WITHOUT MUCH FANFARE AS A
TYPICAL MOISTURE STARVED SYSTEM WITH THE USUAL BROKEN BAND OF
CONVECTION...MOST OF WHICH IS TO OUR NORTH...THIS FOR LATE MONDAY
INTO EARLY TUESDAY. THE SECOND SYSTEM DIGS INTO THE GULF OF MEXICO
AND IS MUCH STRONGER FOR WEDNESDAY. FOR NOW WILL CONTINUE TO
ADVERTISE POPS FROM MONDAY THROUGH WEDNESDAY TO ADDRESS THE
UNCERTAINTY WHILE TRENDING DOWN A BIT FOR OVERNIGHT TUESDAY. NO
CHANGES TO TEMPERATURE FORECAST.
&&
.AVIATION /06Z WEDNESDAY THROUGH MONDAY/...
SYSTEM FINALLY PULLING OUT TO THE NORTHEAST EARLY THIS MORNING.
HIGH AC THEN CIRRUS CEILINGS WILL PULL TO THE EAST AND NORTHEAST
EARLY THIS MORNING. ENOUGH RADIATIONAL COOLING UNDERNEATH THE
THINNED CI/CS AND FINALLY CLEAR SKIES IN GEN ERAL TO PRODUCE IFR AND
LIFR CONDITIONS FROM FOG/DENSE FOG AT TIMES ACROSS FLO AND POSSIBLY
LBT UP TO AND POSSIBLY A FEW HOURS AFTER DAYBREAK. THE COASTAL
TERMINALS WILL BE UNDER THE THICKER AC/CI FOR A LONGER PERIOD OF
TIME EARLY THIS MORNING...AND WILL ONLY SEE PROGGED TEMPO IFR/LIFR
FROM THE FOG TOWARD TO A FEW HOURS AFTER DAYBREAK. MIXING AND THE
SFC BASED INVERSION BREAKING...SHOULD DISSIPATE THE FOG ALTOGETHER
BY 1500Z WITH VFR CONDITIONS THE REMAINDER OF THE DAY. THE STRONG
ADVERTIZED COLD FRONT IS POISED TO PUSH ACROSS THE AREA TERMINALS
FROM WEST TO EAST BETWEEN 02Z THRU 05Z ON THE 27TH WITH MAINLY A
WIND SHIFT TO THE WEST OR NORTHWEST AND AN INCREASE TO 10 TO 20 KT
WITH HIER GUSTS.
EXTENDED OUTLOOK...VFR THROUGH MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
EXPECT N WINDS OF 10 TO 15 KIT OVERNIGHT WITH LOW PRESSURE PASSING
BY TO THE EAST. SEAS OF 2 TO 3 FEET ARE EXPECTED FOR THE OVERNIGHT
PERIOD.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 240 PM WEDNESDAY...OFFSHORE WINDS PRIMARILY DURING THIS
PERIOD AND INCREASING BY LATE THURSDAY NIGHT. STRONG COLD AIR
ADVECTION WILL LIKELY REQUIRE A SMALL CRAFT ADVISORY FOR WINDS
GUSTING NEAR AND IN EXCESS OF 25 KNOTS THURSDAY NIGHT THROUGH
FRIDAY...AS BLUSTERY LOW LEVEL WINDS MIX DOWN IN FREQUENT GUSTS
TO THE SEA SURFACE. WILL ALLOW ANOTHER MODEL RUN HOWEVER TO NAIL
DOWN TIMING AND EXTENT OF NW WINDS AND MARINE HEADLINES SINCE
WE AR STILL 3 PERIODS OUT. THE OFFSHORE FLOW WILL ALLOW FAIRLY
LOW SEA HEIGHTS NEAR SHORE...BUT BUILDING SIGNIFICANTLY OVER
THE FAR OUTER PORTION AND ESPECIALLY THE GULF STREAM. MARINERS
SHOULD CHECK THE LATEST FORECASTS BEFORE HEADING OUT THIS WEEKEND.
LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 240 PM WEDNESDAY...GRADIENT WILL BE QUICKLY RELAXING SATURDAY
AS SURFACE HIGH PRESSURE MOVES ACROSS THE AREA. WINDS WILL BEGIN THE
PERIOD IN A 15-20 KNOT RANGE DIPPING TO BELOW 10 KNOTS BY SATURDAY
EVENING. A RETURN FLOW OF 10-15 KNOTS FROM THE SOUTH DEVELOPS LATER
SUNDAY INTO MONDAY. SEAS SHOULD BE RATHER BENIGN THROUGHOUT WITH A
RANGE OF 2-3 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR SCZ017-023-
024-032-033-039.
NC...DENSE FOG ADVISORY UNTIL 8 AM EST THIS MORNING FOR NCZ087.
MARINE...NONE.
&&
$$
NEAR TERM....31/DOUGH
SHORT TERM...MIKE
LONG TERM....STEPHEN
AVIATION.....43/DOUGH
