Area Forecast Discussion
Issued by NWS Wilmington, NC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KILM 210520
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1220 AM EST SUN DEC 21 2014

.SYNOPSIS...
WEAK HIGH PRESSURE ALONG WITH A FRONT JUST OFFSHORE WILL KEEP CLOUDY
AND COOL CONDITIONS IN PLACE THROUGH SUNDAY. ANOTHER ROUND OF RAIN
IS EXPECTED...ESPECIALLY LATE SUNDAY INTO MONDAY WHEN A STORM MOVES
UP THE COAST. SHOWERS AND THUNDERSTORMS RETURN TUESDAY NIGHT INTO
WEDNESDAY WITH A COLD FRONT. BREEZY BUT CLEAR WEATHER IS EXPECTED
FOR CHRISTMAS DAY. DRY CONDITIONS WILL PERSIST INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1230 AM SUNDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:

SHORTWAVE ACROSS WEST TEXAS IS ENABLING THE SOUTHERN STREAM TO
BUCKLE INTO THE SOUTHERN STATES THIS EVENING. THUS THE SWATH OF
MID LEVEL DRY AIR CURRENTLY ACROSS THE CAROLINAS WILL BE SHORT-
LIVED. REGIONAL RADAR SHOWS LIGHT RAIN ACROSS PORTIONS OF SOUTHERN
SC AND SOUTHEASTERN GA...MOVING E-NE. THINK MOST OF THIS VERY LOW
QPF RAINFALL WILL REMAIN TO OUR SOUTH TONIGHT. ISENTROPIC LIFT
DOESN`T RETURN IN EARNEST ACROSS OUR AREA UNTIL SUNDAY. HAVE HEDGE
POPS UPWARD ACROSS THE SOUTHERN ZONES BY 1200 UTC SUN. OTHERWISE
WITH WEAK COLD AIR ADVECTION AT THE SURFACE AND AMPLE CLOUD COVER
TEMPS WILL ONLY SLOWLY DROP THROUGH THE EARLY MORNING HOURS.
BUMPED UP MINS A FEW DEGREES GIVEN THIS TREND... ESPECIALLY ACROSS
THE PEE DEE AND LBT AREA WHERE TEMPS ARE STILL HANGING ON IN THE
LOWER 40S. PATCHY FOG IS ALSO A GOOD BET THROUGH THE OVERNIGHT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
AS OF 330 PM SATURDAY...DREARY CONDITIONS WILL CONTINUE FOR THE
SHORT TERM PERIOD. A BROAD SOUTHWEST FLOW ALOFT WILL INTERACT WITH A
PERSISTENT BAROCLINIC ZONE JUST OFFSHORE AND A WEDGE OF HIGH
PRESSURE INLAND. THE MODELS ARE IN GENERAL AGREEMENT ON SUNDAY
REMAINING DRY FOR THE MOST PART. THERE COULD BE THE ISOLATED
SPRINKLE OR MORE LIKELY PATCH OF DRIZZLE BUT OVERCAST SKIES AND COOL
CONDITIONS SHOULD DO IT.

A 300MB JET STREAK BRINGS ANOTHER ROUND OF RAIN FOR LATE SUNDAY INTO
MONDAY MORNING. THE NAM AND GFS PAINT MOST OF THE HEAVIER QPF
OFFSHORE WHERE THE BEST DIVERGENCE ALOFT RESIDES. THE BEST
ISENTROPIC LIFT ON THE 300K SURFACE RESIDES WEST OF I-95 AND THE
COAST IS LEFT IN BETWEEN WITH WEAK FORCING. HOWEVER THE QPF AMOUNTS
WEST OF THE INTERSTATE ARE CERTAINLY NOT IMPRESSIVE MAKING THE
OVERALL QPF AMOUNTS FAIRLY PALTRY. BEYOND MONDAY MORNING THE BEST
FORCING MOVES OFF QUICKLY LEAVING OVERCAST/DRIZZLY SKIES.

TEMPERATURE GUIDANCE IS IN GENERAL AGREEMENT OTHER THAN MONDAYS
HIGHS WHEN THE GFS/MAV NUMBERS ARE MUCH WARMER. HARD TO TRUST THESE
HOWEVER AS SURFACE PRESSURE PLOTS SHOW THE WEDGE...ALTHOUGH
WEAKENING REMAINING IN PLACE. I DID USE A BLEND BUT WOULD NOT BE
SURPRISED TO SEE SUBSEQUENT BULLETINS FROM THE GFS COOL.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 330 PM SATURDAY...WEDGE WILL BE ERODED ON TUES AS A WAVE OF
LOW PRESSURE MOVES NORTH ALONG THE CAROLINA COAST. AT THE SAME TIME
A HIGH AMPLITUDE MID TO UPPER TROUGH WILL DIG DOWN FROM THE UPPER
GREAT LAKES INTO TEXAS PUSHING A COLD FRONT EAST. A DEEP S-SW FLOW
WILL BRING PLENTY OF WARM AIR AND MOISTURE INTO THE SOUTHEAST AHEAD
OF THE FRONT. INITIALLY ON TUES SHALLOW COOLER AIR WILL BE IN PLACE
AS THE WARMER AIR OVERRIDES IT PRODUCING INCREASED ISENTROPIC LIFT
AND INCREASED RAIN CHANCES. AS THE DAY WEARS ON...THE WINDS WILL
COME AROUND WITH WARMER AND MOISTER AIR FLOWING IN. ALWAYS TOUGH TO
TIME THIS AS COLD DENSE AIR HOLDS ON LONGER THAN MODELS USUALLY
PREDICT. FOR NOW WILL KEEP WITH TEMPS WARMING THROUGH LATE DAY WITH
WARMER AND MORE HUMID AIR MASS IN PLACE TUES NIGHT INTO WED.

UNSETTLED WEATHER WILL REMAIN AHEAD THE COLD FRONT THROUGH TUES
NIGHT INTO WED BEFORE COLD FRONT MOVES THROUGH LATE WED. INCREASING
LOW LEVEL JET UP TO 40 KTS WILL COMBINE WITH BETTER UPPER LEVEL
FORCING TO PRODUCE MORE WIDESPREAD SHOWERS THROUGH TUES NIGHT INTO
WED. KEPT ISOLATED THUNDERSTORMS IN FORECAST TUES NIGHT INTO WED AS
WARM FRONT LIFTS NORTH AND LOCAL AREA GETS INTO BEST MOISTURE AND
LIFT. PCP WATER VALUES REACH UP TO 2 INCHES ALONG THE COAST WED AFTN

THE DIGGING MID TO UPPER TROUGH WILL PUSH THE COLD FRONT THROUGH WED
NIGHT BEFORE FINALLY MOVE OFF SHORE BY THURS MORNING LEAVING DRIER
AND COOLER WEATHER FOR CHRISTMAS DAY. OVERALL EXPECT CLOUDY AND DAMP
TO WET WEATHER THROUGH THE FIRST HALF OF THE PERIOD WITH COOLER MORE
SEASONABLE WEATHER THURS INTO FRI AS HIGH PRESSURE BUILDS ACROSS THE
SOUTH. THE HIGH WILL SHIFT OFF SHORE THROUGH FRI LEAVING A LIGHT
RETURN FLOW AND WARMER TEMPS FRI INTO SATURDAY WITH A GOOD DEAL OF
SUNSHINE. NEXT COLD FRONT SHOULD MOVE THROUGH SAT NIGHT BUT LOOKS
LIKE IT MAY BE LACKING ANY DEEP MOISTURE.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...EXPECT CIGS TO FLUCTUATE BETWEEN MVFR/VFR OVERNIGHT
WITH BRIEF PERIODS OF TEMPO IFR POSSIBLE EARLY THIS MORNING. THE
3-6KFT LAYER REMAINS SATURATED THROUGH THE PERIOD...SO STRATOCU
WILL PERSIST AS A COASTAL TROUGH SHARPENS OFFSHORE. ALTHOUGH THERE
ARE A FEW PATCHES OF 800-1000 FT STRATUS OUT THERE TONIGHT...DO
NOT ANTICIPATE PERSISTENT CIGS AT THESE LEVELS BASED ON THE
FORECAST SOUNDINGS AND SREF PROBS. CIGS MAY BRIEFLY IMPROVE TO VFR
IN THE MORNING BEFORE ANOTHER ROUND OF MOIST ISENTROPIC LIFT
BRINGS MORE -RA AND LOWERS THEM BACK DOWN TO MVFR AGAIN. PRECIP
SHOULD BEGIN AROUND 15Z AT THE SOUTHERN TERMINALS AND AFTER 18Z AT
KILM/KLBT. NORTHEAST WINDS AOB 10 KT WILL PERSIST THROUGH THE DAY.
AFTER 00Z MON...CIGS WILL DROP FURTHER AS RAIN CONTINUES TO FALL.
WOULD NOT BE SURPRISED TO SEE IFR CIGS BY THE END OF THE PERIOD
ESPECIALLY ALONG THE COAST...BUT FOR NOW WILL KEEP ALL SITES MVFR.

EXTENDED OUTLOOK...RAIN LIKELY MON WITH MVFR/IFR CIGS AS A COASTAL
TROUGH DEVELOPS OFFSHORE. SHOWERS/TEMPO MVFR EXPECTED TUE/WED
AHEAD OF A STRONG COLD FRONT. GUSTY WINDS WED/THU BEFORE AND AFTER
FROPA. THU WILL BE VFR AT ALL TERMINALS.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM SUNDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:

NORTH TO NORTHEAST FETCH WITH LOW PRESSURE TO THE SOUTH AND
RIDGING FROM THE NORTH HAS RESULTED IN STEEP 3 TO 5 FT. THE
DOMINANT PERIOD IS AROUND 5 SECONDS THIS EVENING...AND A SIMILAR
SEA STATE IS EXPECTED OVERNIGHT. FIRST BATCH OF LIGHT RAIN IS
EXITING THE CAPE FEAR COASTAL WATERS. TRENDS FOR INCREASING LIGHT
RAIN...ESPECIALLY SOUTHERN WATERS...DURING THE EARLY MORNING
HOURS.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 330 PM SATURDAY...A FAIRLY BRISK NORTHEAST FLOW WILL PERSIST
ACROSS THE COASTAL WATERS SUNDAY IN BETWEEN A BAROCLINIC ZONE TO THE
EAST AND HIGH PRESSURE INLAND. AS LOW PRESSURE DEVELOPS AND MOVES UP
ALONG THIS FRONT SUNDAY NIGHT...THE FLOW WILL TURN MORE EASTERLY.
SPEEDS THROUGHOUT WILL BE 15-20 KNOTS. SOME HIGHER SEAS CAN BE
EXPECTED WITH THE SOMEWHAT PROLONGED NATURE OF THE WINDS...3-5 FEET.
CANT RULE OUT A FEW SIX FOOTERS BUT THINK A SMALL CRAFT HEADLINE CAN
BE AVOIDED. LIGHTER WINDS AND SEAS CAN BE EXPECTED MONDAY ALTHOUGH
THE FLOW WILL GENERALLY BE THE SAME.

LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 330 PM SATURDAY...WAVE OF LOW PRESSURE WILL MOVE UP THE
CAROLINA COAST ON TUES WITH WINDS COMING AROUND THROUGH THE DAY.
LIGHT NORTHERLY WINDS WILL SHIFT AROUND BECOMING MORE ON SHORE
THROUGH THE DAY AND EVENTUALLY SOUTHERLY BY TUES EVENING.

A LARGE AND POTENT STORM SYSTEM WILL PUSH A COLD FRONT EAST WITH
INCREASING SOUTHERLY WINDS IN A TIGHTENING GRADIENT FLOW TUES NIGHT
INTO WED. WINDS WILL INCREASE UP TO 15 TO 25 KTS TUES NIGHT INTO WED
AHEAD OF THE COLD FRONT. THIS WILL PUSH SEAS UP FROM 2 TO 4 FT EARLY
TUES TO 3 TO 5 FT BY LATE TUES. WNA SHOWS SEAS RAMPING UP ABOVE 6 FT
BY WED MORNING AND POSSIBLE UP TO 7 TO 9 FT IN OUTER WATERS IN
STRONGER SW TO W FLOW AS FRONT MOVES THROUGH THE WATERS LATE WED
INTO WED NIGHT. EXPECT SMALL CRAFT CONDITIONS WED AND LASTING INTO
THURS WITH HIGHEST SEAS GETTING PUSHED FARTHER OFF SHORE IN STRONGER
W-NW FLOW BEHIND FRONT.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...SHK
NEAR TERM...REK/III
SHORT TERM...SHK
LONG TERM...RGZ
AVIATION...BJR
MARINE...REK/III/RGZ/SHK



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.