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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 100723
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
223 AM EST WED FEB 10 2010

.SYNOPSIS...
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LOW PRESSURE NORTHEAST OF CAPE HATTERS WILL MOVE AWAY FROM THE
CAROLINAS AND RAPIDLY INTENSIFY TODAY. THIS WILL CREATE A VERY
TIGHT PRESSURE GRADIENT WITH STRONG OFFSHORE WINDS DEVELOPING. THE
NEXT IN THE PARADE OF LOW PRESSURE SYSTEMS WILL MOVE BY TO OUR
SOUTH FRIDAY NIGHT AND SATURDAY. HIGH PRESSURE WILL BUILD IN FOR
THE LATTER HALF OF THE WEEKEND...WITH BELOW NORMAL TEMPERATURES
CONTINUING.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
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AS OF 2 AM WEDNESDAY...BIG STORY FOR TODAY WILL BE THE WINDS. COLD
FRONT NOW ADVANCING ACROSS THE EASTERN CAROLINAS AS A LOW PRESSURE
SYSTEM CONSOLIDATES EAST OF HATTERAS. LOW WILL DEEPEN RAPIDLY AS
IT MOVES NORTHEAST...FOLLOWED BY A VERY STRONG COLD SURGE WHICH
WILL BLANKET THE EASTERN CAROLINAS. TIGHT GRADIENT AND STRONG
WINDS JUST OFF THE DECK WILL ALLOW WINDS OF UP TO AROUND 30
KTS...WITH HIGHER GUSTS...TO MIX DOWN TO THE SURFACE THIS
AFTERNOON. HAVE KEPT WIND ADVISORY IN EFFECT AS IS. MOS GUIDANCE
REAL CLOSE ON TEMPS TODAY AND TONIGHT. STRONG COLD ADVECTION WILL
KEEP DAYTIME TEMPERATURE READINGS ABOUT 10 TO 15 DEGREES BELOW
NORMAL...LOWER O MID 40S. CONTINUED MIXING OVERNIGHT WILL KEEP
TEMPS FROM DROPPING BELOW THE MID 20S...STILL CLOSE TO 10 DEGREES
BELOW NORMAL.
-- End Changed Discussion --

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
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AS OF 2 AM WEDNESDAY...MODIFYING ARCTIC HIGH CONTINUES TO BUILD IN
FROM THE NORTHWEST THU INTO FRI. DESPITE AN END TO COLD ADVECTION
TEMPERATURES WILL REMAIN BELOW CLIMO ON THU. LOW LEVEL COLD AIR
WILL KEEP HIGHS IN THE MID TO UPPER 40S. MODERATE RADIATIONAL
COOLING THU NIGHT WITH TEMPERATURES DROPPING INTO THE MID TO UPPER
20S.

HIGH PRESSURE REMAINS NORTH OF THE AREA FRI AS SHORTWAVE TROF MOVES
ACROSS THE GULF OF MEXICO. ALL OF THE GUIDANCE IS DEVELOPING A
SURFACE LOW ASSOCIATED WITH THE UPPER FEATURE. BOTH TRACK EAST
ACROSS FL AND THEN TURN NORTHEAST. STILL SEEING CONSIDERABLE TRACK
AND TIMING DIFFERENCES BUT ONLY THE 00Z GFS SOLUTION WOULD RESULT IN
A DRY END TO THE PERIOD. THE 12/00Z CANADIAN RUNS OFFER A VERY
INTERESTING SOLUTION...ONE WHICH WOULD RESULT IN CONSIDERABLE SNOW
FOR AT LEAST PART OF THE FORECAST AREA FRI NIGHT INTO SAT. HOWEVER
THIS SOLUTION IS AN OUTLIER WITH NO SUPPORT. FAVORED SCENARIO IS A
COMPROMISE BETWEEN THE 00Z GFS AND 12/00Z CANADIAN TRACKS WHICH IS
SIMILAR TO THE 00Z NAM/ECMWF AND RESULTS IN A BRUSH WITH FROZEN
PRECIP BUT NOTHING MORE. ADDED SLIGHT CHANCE POPS FOR FRI NIGHT BUT
THERE IS PLENTY OF LOW LEVEL DRY AIR THAT MUST BE OVERCOME BEFORE
PRECIP CAN REACH THE SURFACE. ONCE THE TRACK AND TIMING ISSUES ARE
RESOLVED POPS WILL MORE THAN LIKELY BE ADJUSTED. TEMPERATURES WILL
REMAIN BELOW CLIMO FRI AND FRI NIGHT.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
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AS OF 2 AM WEDNESDAY...LOW PRESSURE OFF THE SOUTHEAST COAST AT THE
START OF THE PERIOD WILL BE HAVING SOME IMPACT ON THE AREA...THE
QUESTION IS HOW MUCH. LATEST ECMWF HAS THE LOW 300-400 MILES OF
THE COAST WHILE THE GFS IS OVER 500 MILES AND THE CANADIAN IS
UNDER 200 MILES. SHORTWAVE RESPONSIBLE FOR THE SURFACE LOW IS JUST
ENTERING SOUTHERN CA...HOPEFULLY MORE SURFACE AND UPPER LEVEL
SAMPLING WILL HELP THE CANADIAN/ECMWF/GFS ZERO IN ON A SOLUTION.
UNTIL THEN WILL KEEP FORECAST FOR SAT CLOSE TO THE ECMWF WHICH IS
BETWEEN THE GFS/CANADIAN.

WEAK HIGH PRESSURE BUILDS IN FROM THE WEST LATER SAT AND SUN. SUN
EVENING CENTER OF SURFACE HIGH...OVER THE GULF COAST...IS PUSHED
FARTHER SOUTH AS NEXT SHORTWAVE/CLIPPER SYSTEM DROPS OUT OF THE
UPPER MIDWEST. SHORTWAVE HAS MOISTURE ASSOCIATED WITH IT BUT
FORECAST SOUNDINGS SHOW LOTS OF DRY AIR IN THE LOWER LEVELS. MAY END
UP WITH CLOUD COVER SUN NIGHT INTO MON WITH COLD FRONTAL PASSAGE
MONDAY MORNING FOLLOWED BY ANOTHER ROUND OF COLD ADVECTION MON INTO
TUE. TEMPERATURES WILL REMAIN BELOW TO WELL BELOW CLIMO THROUGH THE
PERIOD.
-- End Changed Discussion --

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... 
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COLD FRONT PASSING
THROUGH THE CWA WITH CONDITIONS IMPROVING. AROUND 08Z...COLD AIR
ADVECTION BEGINS WITH WINDS INCREASING RAPIDLY TO AROUND 15 KTS
WITH GUSTS OVER 20. BY 12Z...GOOD MIXING THROUGHOUT THE COLUMN
WILL BRING STRONG WINDS DOWN TO THE SURFACE...WITH GUSTS OVER 35
KTS POSSIBLE THROUGHOUT THE DAY...WITH LBT AND ILM IN THE
STRONGEST GRADIENT. EXPECTED ONLY A SLIGHT DECREASE IN THE WINDS
AT THE END OF THE FORECAST PERIOD WITH VFR CONDITIONS. THERE WILL
BE A SLIGHT CHANCE OF A MVFR/VFR STRATA CU CEILING AROUND MID
MORNING.

EXTENDED OUTLOOK...HIGH CONFIDENCE VFR WEDNESDAY EVENING THROUGH
FRIDAY. MEDIUM CONFIDENCE FOR PERIODS OF MVFR SATURDAY AS UPPER
LEVEL SHORT WAVE TROUGH BRINGS SHOWERS. SUNDAY STARTS VFR THEN AS
COLD FRONT APPROACHES FROM THE WEST...PERIODS OF MVFR/IFR WITH
SHOWERS.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
AS OF 2 AM WEDNESDAY...STRONG COLD SURGE OVER THE WATERS TODAY AS
A LOW PRESSURE SYSTEM DEEPENS RAPIDLY EAST OF HATTERAS. THIS WILL
GENERATE AND MAINTAIN WESTERLY TO NORTHWESTERLY GALE FORCE WINDS
OVER THE WATERS THRU ALMOST THE ENTIRE NEAR TERM. SEAS WILL BUILD
UP TO AROUND 10 FT WELL OFFSHORE AS A RESULT. WINDS ALREADY
REACHING 25 KTS OUT AT 41013...WITH SEAS OF 7 FT. DUE TO LIMITED
FETCH OF OFFSHORE WINDS...SEAS NEAR SHORE NOW AROUND 3 TO 5 FT.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 2 AM WEDNESDAY...OFFSHORE FLOW WILL CONTINUE THROUGH THE
PERIOD. ON THU HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE
NORTHWEST BUT WEAKENING GRADIENT THROUGHOUT THE DAY WILL LEAD TO A
STEADY DECREASE IN SPEEDS. WINDS WILL BE UNDER GALE FORCE AT THE
START OF THE PERIOD...BUT SCA WILL LIKELY BE NEEDED INTO THU
AFTERNOON. FLOW BECOMES MORE NORTHERLY THU NIGHT INTO FRI AS CENTER
OF HIGH MOVES INTO THE OH VALLEY. LOW PRESSURE DEVELOPING OVER THE
EASTERN GULF OF MEXICO WILL CROSS FL LATER FRI BEFORE TURNING
NORTHEAST. TIGHTENING GRADIENT WILL INCREASE NORTHERLY WINDS TO NEAR
15 KT LATE FRI NIGHT.

LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 2 AM WEDNESDAY...NORTH TO NORTHWEST FLOW AROUND 15 KT SAT WILL
BEGIN TO WEAKEN LATE SAT NIGHT AS SURFACE LOW OFF THE COAST MOVES
AWAY FROM THE AREA. WEAK HIGH PRESSURE BUILDING IN SAT NIGHT ENSURES
FLOW REMAINS OFFSHORE INTO SUN. SURFACE RIDGE AXIS SHIFTS SOUTH OF
THE WATERS SUN AFTERNOON WITH WEST TO SOUTHWEST WINDS DEVELOPING SUN
NIGHT. GRADIENT TIGHTENS UP AHEAD OF NEXT COLD FRONT...EXPECTED TO
CROSS THE WATERS AT THE END OF THE PERIOD. PINCHED GRADIENT MAY
PRODUCE 15 TO 20 KT WINDS LATE SUN NIGHT. DURATION WILL BE SHORT AND
HEADLINES ARE NOT ANTICIPATED AT THIS TIME.
-- End Changed Discussion --

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...WIND ADVISORY FROM 8 AM THIS MORNING TO 8 PM EST THIS EVENING
     FOR SCZ017-023-024-032>034-039-046.

NC...WIND ADVISORY FROM 8 AM THIS MORNING TO 8 PM EST THIS EVENING
     FOR NCZ087-096-097-099>101.

MARINE...GALE WARNING UNTIL 5 AM EST THURSDAY FOR AMZ250-252-254-256.

&&

$$

NEAR TERM...REK
SHORT TERM...III
LONG TERM...III
AVIATION...DL