FXUS62 KILM 051122
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
620 AM EST SAT DEC 5 2009
.SYNOPSIS...
WET WEATHER CAN BE EXPECTED THIS MORNING AS A LOW PRESSURE SYSTEM
CONSOLIDATES NEAR THE OUTER BANKS. RAIN WILL COME TO AN END THIS
AFTERNOON AS THE LOW PULLS WELL NORTHEAST OF THE REGION. COOLER
AND DRIER AIR CAN BE EXPECTED SUNDAY AS HIGH PRESSURE BUILDS IN
FROM THE WEST. A COASTAL TROUGH COULD BRING A FEW SHOWERS TO THE
EASTERN CAROLINAS ON MONDAY. A DEEPENING LOW PRESSURE SYSTEM
APPROACHING FROM THE SOUTHWEST...COULD BRING SIGNIFICANT RAIN TO
THE REGION WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...SURFACE LOW PRESSURE OFF THE FLORIDA EAST
COAST WILL MOVE NORTHEAST TODAY...STRENGTHENING AS IT MOVES JUST OFF
THE CAROLINA COASTLINE. A VERY DEEP AND COLD UPPER TROUGH CENTERED
OVER THE LOWER MISSISSIPPI VALLEY. THIS SYSTEM WAS RESPONSIBLE FOR
PRODUCING THE EARLIEST SNOWFALL ON RECORD FOR PORTIONS OF COASTAL
TEXAS INCLUDING HOUSTON. EXCELLENT UPPER DIVERGENCE OVER THE EASTERN
CAROLINAS THIS MORNING WILL PRODUCE WIDESPREAD RAINFALL WITH TOTALS
POTENTIALLY REACHING 1 INCH NEAR THE COAST. THE BACK EDGE OF THE
RAIN WILL ACCOMPANY DRYING AT 700 MB AND SHOULD REACH OUR SOUTH
CAROLINA FORECAST AREA DURING THE MID MORNING HOURS...AND NORTH
CAROLINA AROUND NOON. SUFFICIENT LOW-LEVEL MOISTURE WILL LINGER FOR
PERHAPS SOME LIGHT DRIZZLE INTO THE EARLY AFTERNOON.
AFTER THE LOW SWINGS BY OFFSHORE LATE THIS MORNING...WINDS WILL TURN
NORTHWESTERLY WITH STRONG COLD ADVECTION BEGINNING. THE 850 MB ZERO
LINE WILL SWEEP EAST AND REACH THE COAST BY EVENING. EVEN THE
LOW-LEVEL MOISTURE WILL BE CLEARING OUT BY THAT TIME MEANING OUR
AREA WILL NOT DEAL WITH THE POTENTIAL FOR SNOW LIKE MUCH OF THE
SOUTHERN U.S. HAS IN THE PAST 24 HOURS. CLEARING SKIES WILL COINCIDE
WITH A WEAKENING BOUNDARY LAYER WIND FIELD BEFORE DAYBREAK AND
SUNDAY MORNING SHOULD BE THE COLDEST OF THE SEASON FOR MOST
LOCATIONS.
HIGHS TODAY ARE NOT STRAIGHTFORWARD. VERY WARM AIR /MID 60S!/ IS
SITTING LITERALLY JUST 10 MILES OFF COASTAL NORTH CAROLINA AND AN
HOUR OR TWO OF EASTERLY WINDS THIS MORNING COULD CREATE A HUGE
FORECAST BUST AT THE COAST. VIRTUALLY ALL GUIDANCE WE HAVE SHOWS THE
COOL AIRMASS WILL PERSIST EVEN DOWN INTO WILMINGTON...SO WE HAVE
FORECAST HIGHS RANGING FROM THE MID 50S AT THE COAST TO THE LOWER
50S INLAND. TONIGHT ASSUMING WINDS DIE AWAY ON SCHEDULE LOWS SHOULD
REACH AROUND 30 INLAND...AND LOWER 30S AT THE COAST. THIS SHOULD BE
THE FIRST FREEZE OF THE SEASON FOR THE WILMINGTON AND NORTH MYRTLE
BEACH AIRPORTS...BUT NO FREEZE WARNINGS WILL BE ISSUED GIVEN WE ARE
WELL PAST THE CLIMATOLOGICAL DATES FOR THE FIRST FREEZE.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...HIGH PRESSURE WILL MIGRATE EAST ACROSS
VIRGINIA SUNDAY AND SUNDAY NIGHT...RESULTING IN DRY BUT
UNSEASONABLY CHILLY WEATHER. BASED ON LOW-LEVEL THICKNESS PROGS
AND SHALLOW COLD NNE FLOW...EXPECT SUN AFTERNOON HIGHS JUST EITHER
SIDE OF 50 DEGREES...WHICH COMES IN A DEGREE OR TWO UNDER THE
COOLER NAM MOS. DEVELOPING COASTAL TROF ON SUNDAY NIGHT WILL
PROVIDE JUST ENOUGH CLOUD COVER TO KEEP TEMPS FROM BOTTOMING
OUT...BUT NOT MUCH IN THE WAY OF PRECIP OVER LAND BEFORE DAYBREAK
MONDAY.
THE COASTAL TROF WILL SHARPEN UP ENOUGH ON MONDAY TO MERIT LOW
CHANCE POPS FOR THE COASTAL ZONES. THINK THE GFS IS A BIT TOO
BULLISH IN SLINGING PRECIP INLAND AS THE ONSHORE FLOW IS QUITE
SHALLOW. WENT WITH SLIGHT CHANCE FOR THE INLAND ZONES.
DRY WX AND SEASONABLE TEMPS MONDAY NIGHT AS HIGH PRESSURE NOSES IN
FROM THE NORTHWEST...AND THE COASTAL TROF BECOMES ABSORBED INTO A
PROGRESSIVE NORTHERN STREAM SYSTEM.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...VIGOROUS LOW PRESSURE SYSTEM WILL IMPACT THE
AREA TUESDAY NIGHT AND WEDNESDAY...WITH SOME EVIDENCE OF PHASING
BETWEEN THE NORTHERN AND SOUTHERN STREAMS. RAMPED POPS TO HIGH
CHANCE FOR BOTH TUE NIGHT AND WED...WITH MENTION OF ISOLATED
THUNDER IN A POTENTIAL WARM SECTOR ON WEDNESDAY. UNSEASONABLY MILD
HIGHS WEDNESDAY...COULD GET CLOSE TO 70. FROPA WEDNESDAY NIGHT
WILL BE FOLLOWED BY SPRAWLING HIGH PRESSURE...WHICH WILL KNOCK
TEMPS BACK TO THE LOW SIDE OF CLIMO.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
FAIRLY STABLE SITUATION THIS MORNING...WITH MAINLY IFR CONDITIONS TO
CONTINUE THROUGH THE EARLY AFTERNOON. CRE AND MYR MAY OSCILLATE FROM
MVFR TO IFR IN THE MORNING HOURS. LIGHT TO MODERATE RAIN WILL HANG IN
THERE FOR THE NEXT 4-5 HOURS...WITH PRECIPITATION SLOWLY ENDING FROM
WEST TO EAST BY MID AFTERNOON. COLD AIR ADVECTION THIS AFTERNOON
WILL QUICKLY SCATTER OUT THE CEILINGS...AND THERE MAY BE A PERIOD OF
GUSTY WINDS AS THE MIXING BEGINS. WINDS WILL DIMINISH TONIGHT.
EXTENDED OUTLOOK...VFR SUNDAY UNDER HIGH PRESSURE AND MVFR MONDAY
AFTERNOON WITH RAIN POSSIBLE. IFR TUESDAY NIGHT THROUGH WEDNESDAY
MORNING IN RAIN.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...LOW PRESSURE DEEPENING OFF THE FLORIDA EAST
COAST WILL RACE NORTHEAST JUST OFF THE CAROLINA COAST LATER TODAY.
THE BOUNDARY THE FRONT IS MOVING ALONG IS SITTING OVER THE OUTER
EDGE OF THE COASTAL WATERS THIS MORNING. THE BAGGY GRADIENT
SURROUNDING THIS BOUNDARY IS PROVIDING GENERALLY LIGHT WINDS
CURRENTLY. WIND DIRECTIONS VARY FROM NORTHEAST NEAR THE COAST TO
EAST OR SOUTHEASTERLY IN THE OFFSHORE WATERS AS REPORTED BY THE
FRYING PAN SHOALS BUOY. AFTER THE SURFACE LOW PASSES BY DURING THE
LATE MORNING HOURS...WINDS WILL SHIFT OFFSHORE AND RAPIDLY
INCREASE THROUGH THE AFTERNOON AS STRONG COLD ADVECTION OVERSPREAD
THE AREA. FORECAST MODELS SHOW SUSTAINED WINDS INCREASING INTO THE
20-25 KT RANGE WITH 30 KT GUSTS EXPECTED. THE PERIOD OF STRONGEST
WINDS WILL OCCUR AROUND SUNSET THROUGH 10 PM...WITH A GRADUAL
IMPROVING TREND TOWARD MORNING.
SEAS ARE CURRENTLY RUNNING 3-4 FT NORTH OF CAPE FEAR...AND 2-3 FT TO
THE SOUTH. SEAS NEARSHORE WILL FALL THIS AFTERNOON WITH THE OFFSHORE
FETCH ALTHOUGH PERIODS WILL SHORTEN SUBSTANTIALLY. OUT BEYOND 10
MILES FROM SHORE SEAS WILL BUILD TO 4-5 FT LATE THIS AFTERNOON
THROUGH TONIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...HIGH PRESSURE JUST TO OUR NORTH AND WEST
WILL PROVIDE BENIGN N-NE WINDS FOR SUNDAY AND MOST OF SUNDAY
NIGHT. AS THE COASTAL TROF BECOMES MORE OF A PLAYER...WINDS WILL
VEER TO EAST BY DAYBREAK MONDAY. THE COASTAL TROF MAY ACTUALLY
IMPINGE ON THE WATERS FOR A PERIOD DURING THE DAY ON
MONDAY...BEFORE HIGH PRESSURE NOSING IN FROM THE NORTHWEST PUSHES
IT BACK OUT TO SEA AS MORE OF A COLD FRONT. COULD SEE A PERIOD OF
VARIABLE WINDS AS THIS HAPPENS...BUT I HAVE MORE CONFIDENCE IN NW
WINDS FOR MONDAY NIGHT. EITHER WAY...SPEEDS WILL BE 15 KT OR LESS
FOR MOST OF THE PERIOD...AND SEAS GENERALLY 2-3 FT.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...EXPECT STEADILY DETERIORATING CONDITIONS
FROM LATE TUESDAY THROUGH MOST OF WEDNESDAY. NORTH WINDS EARLY
TUESDAY WILL VEER TO EAST BY TUESDAY EVENING...AT WHICH POINT SEAS
CAN BEGIN TO BUILD. WARM FRONT WILL LIFT NORTH ACROSS THE WATERS
TUE NIGHT...AND EVEN IN THE STABLE WARM SECTOR ON WEDNESDAY THE
50-60 KT LOW-LEVEL JET SHOULD MIX DOWN 25 KT WINDS AT THE
SURFACE. PROLONGED AND OPEN FETCH WILL ALLOW SEAS TO REALLY CRANK
UP...POSSIBLY REACHING 8-9 FT ALONG FRYING PAN SHOALS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 3 AM EST
SUNDAY FOR AMZ254-256.
SMALL CRAFT ADVISORY FROM NOON TODAY TO 3 AM EST SUNDAY FOR
AMZ250-252.
&&
$$
NEAR TERM...TRA
SHORT TERM...RAS
LONG TERM...RAS
AVIATION...43
