National Weather Service Raw Text Product

673 
FXUS62 KILM 241100
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
558 AM EST WED DEC 24 2014

.SYNOPSIS...
LOW PRESSURE TO THE WEST OF THE APPALACHIANS WILL DEEPEN AND LIFT
NORTH TOWARD THE GREAT LAKES PULLING A COASTAL FRONT FARTHER
INLAND AND NORTH THROUGH TODAY. THIS LOW PRESSURE SYSTEM WILL DRAG
A COLD FRONT THROUGH THE COASTAL CAROLINAS TONIGHT AS IT LIFTS OFF
TO THE NORTHEAST. DRY HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST
CHRISTMAS DAY INTO FRIDAY BEFORE MOVING OFF THE COAST BY SATURDAY.
A COLD FRONT WILL DROP INTO THE SOUTHEAST ON SUNDAY WITH A A FEW
WAVES OF LOW PRESSURE DEVELOPING EARLY TO MID WEEK NEXT WEEK
LEAVING UNSETTLED WEATHER ACROSS THE CAROLINAS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM WEDNESDAY...THE COASTAL FRONT/WARM FRONT THAT HAS SAT 
OFFSHORE FOR THE PAST FEW DAYS IS FINALLY PRESSING INLAND. THIS IS 
ALLOWING A TROPICAL AIRMASS INTO THE AREA WITH TEMPS AND DEWPOINTS 
ON THE WESTERN EDGE OF THE GULF STREAM NOW IN THE 70S. IN THE UPPER 
LEVELS A DEEP TROUGH JUST WEST OF THE MISSISSIPPI RIVER WILL MOVE 
INTO THE APPALACHIANS TONIGHT. EXCELLENT SYNOPTIC LIFT AIDED BY FLOW 
INTO THE RIGHT-ENTRANCE REGION OF A 140 KNOT 200 MB JET STREAK 
SHOULD BRING ANOTHER WAVE OF MODERATE TO HEAVY RAINFALL INTO THE 
AREA THIS MORNING THROUGH EARLY THIS AFTERNOON. EMBEDDED 
THUNDERSTORMS REMAIN POSSIBLE AS ELEVATED CAPE AROUND 500 J/KG (AND 
SURFACE-BASED CAPE OF 250-500 J/KG) IS EXPECTED TO DEVELOP LATER 
THIS MORNING. THE SEVERE WEATHER THREAT REMAINS LOW DUE TO LIMITED 
BOUNDARY LAYER INSTABILITY AND INCREASINGLY UNIDIRECTIONAL WINDS 
WITHIN THE LOWEST 3 KM.

850 MB TEMPS RISING TO +14C AND DEEP SOUTH FLOW WILL HELP PUSH 
TEMPERATURES IN THE 70S TODAY AWAY FROM THE BEACHES EVEN WITHOUT 
SIGNIFICANT INSOLATION. WHERE TEMPS CAN EXCEED 70 LOOK FOR ENOUGH 
MIXING TO DEVELOP TO TRANSPORT DOWN 35 MPH WIND GUSTS TO THE 
SURFACE. IF ENOUGH SUNSHINE COULD SOMEHOW DEVELOP TO PUSH 
TEMPERATURES INTO THE MID 70S (PRODUCING 2000 FEET OF VERTICAL 
MIXING) WIND GUSTS COULD CONCEIVABLY REACH 45 MPH!

NEAR THE BEACHES WINDS OFF THE COLD OCEAN WILL ADVECT A SHALLOW VERY 
STABLE BOUNDARY LAYER ONSHORE WITH TEMPERATURES LIKELY STUCK IN THE 
UPPER 50S AND 60S ALL DAY. DENSE SEA FOG COULD ADVECT ONSHORE AS 
WELL...HOWEVER ENOUGH WIND SHOULD EXIST TO MIX THIS FOG UPWARD INTO 
A RAGGED STRATUS DECK BY NOON.

PREFERRED MODELS TODAY INCLUDE THE 00Z NAM...00Z WRF-NMM...AND TO A 
LESSER EXTENT THE 00Z CANADIAN. A LULL IN PRECIPITATION IS EXPECTED 
DURING THE MID TO LATE AFTERNOON HOURS...WITH SHOWERS AND ISOLATED 
T-STORMS FIRING ALONG THE COAST THIS EVENING. THE ACTUAL SURFACE 
COLD FRONT SHOULD CROSS INTERSTATE 95 AROUND MIDNIGHT...POSSIBLY 
ACCOMPANIED BY ONE FINAL BAND OF SHOWERS. LOWS SHOULD RANGE FROM 
50-55...WARMEST AT THE NC BEACHES.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...A COLD FRONT WILL BE PUSHING FARTHER OFF
SHORE THROUGH THURS AS HIGH PRESSURE BUILDS UP FROM GULF COAST.
ANY LINGERING PCP OR MOISTURE WILL BE SCOURED OUT AS MID TO UPPER
TROUGH MOVES EAST LEAVING A DEEP DRY AND COOLER W-NW FLOW BEHIND
IT. EXPECT PCP WATER VALUES DOWN FROM UP NEAR 2 INCHES THE NIGHT
BEFORE TO A QUARTER OF INCH BY THURS AFTERNOON AS COLUMN DRIES
OUT. OVERALL EXPECT CLEARING SKIES ON CHRISTMAS DAY WITH SUNSHINE
MAKING AN APPEARANCE FOR THE FIRST TIME IN SEVERAL DAYS. TEMPS
SHOULD NOT MOVE MUCH ON THURS AS A WARM START TO THE DAY WILL BE
FOLLOWED BY GUSTY W-NW WINDS BRINGING IN RELATIVELY COOLER AIR.
MODELS HAVE BEEN CONSISTENTLY BACKING OFF ON CAA BEHIND THE FRONT
WITH 850 TEMPS ONLY FALLING ABOUT 6 C BEHIND FRONT BEFORE LEVELING
OFF AND RISING SLIGHTLY THROUGH FRI. TEMPS THURS NIGHT SHOULD BE
DOWN IN THE 30S AND BASICALLY EXPECT SEASONABLE TO ABOVE NORMAL
TEMPS IN THE FORECAST AS HIGH PRESSURE BUILDS UP FROM THE GULF
COAST OVER THE SOUTHEAST THROUGH FRI. 

THE CENTER OF THE HIGH ALMOST DIRECTLY OVERHEAD FRI AFTN WILL
SHIFT OFF SHORE BY FRI NIGHT LEAVING A LIGHT RETURN FLOW. THIS
WILL HELP TO CAUSE A SLIGHT RISE IN DEWPOINT TEMPS AND THEREFORE
WILL KEEP TEMP A BIT HIGHER THAN THE NIGHT BEFORE BUT THE WINDS
WILL BE LIGHT ENOUGH UNDER CLEAR SKIES TO PRODUCE DECENT
RADIATIONAL COOLING. THIS WILL BRING TEMPS DOWN CLOSER TO 40 FOR
FRI NIGHT. 

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 330 AM WEDNESDAY...RIDGE OF HIGH PRESSURE UP THE SOUTHEAST
COAST ON SATURDAY WILL SHIFT EAST THROUGH EARLY NEXT WEEK. THIS
WILL ALLOW A RETURN FLOW TO SET UP WITH SW-W WINDS THROUGH THE
LOW TO MID LEVELS OF THE ATMOSPHERE. INITIALLY SHOULD SEE A FAIR
AMOUNT OF SUNSHINE ON SATURDAY BUT A COLD FRONT WILL DROP SOUTH ON
SUNDAY LEAVING SHALLOW COOL AIR IN PLACE. SHOULD SEE CLOUDS AND
PCP SPREAD OVER THE CAROLINAS SAT NIGHT INTO SUNDAY AS COLD FRONT
DROPS SOUTH WITH SOME DECENT ISENTROPIC LIFT DEVELOPING. THE GFS
AND ECMWF SHOW A FEW WAVES OF LOW PRESSURE MOVING UP FROM THE
GULF COAST ALONG THIS FRONT THROUGH NEXT WEEK. MAY END UP WITH AN
EXTENDED PERIOD OF UNSETTLED WEATHER AS POSSIBLE WEDGE SETS UP.

TEMPS ON SAT INTO SUNDAY SHOULD REMAIN ON THE WARM SIDE WITH 60S
MOST PLACES. SOME UNCERTAINTY EXISTS WITH LOCATION OF COLD FRONT
AS ECMWF KEEPS IT NORTH AND SHOWS WAVES OF LOW PRESSURE MOVING
ALONG FRONT TO THE NORTH OF LOCAL AREA. THIS COULD KEEP LOCAL AREA
IN WARMER SW FLOW AT THE SURFACE WITH WEDGE HOLDING INLAND AND TO
OUR NORTH.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...MODERATE SHOWERS ARE TRAINING OVER THE WESTERN PORTION 
OF THE REGION...WITH ANOTHER SLUG OF PRECIP MOVING UP THE COAST. 
THIS BATCH WILL MOVE INTO THE MYRTLES IN ABOUT AN HOUR. THE HRRR 
MODEL INITIALIZED FAIRLY WELL AND SHOWS THE PRECIP WEAKENING LATER 
THIS MORNING. SOUTHERLY WINDS WILL INCREASE THIS MORNING...GUSTING 
NEAR 20 KTS AT TIMES. ANOTHER BATCH OF PRECIP WILL EMERGE JUST AHEAD 
OF THE COLD FRONT THIS AFTERNOON THROUGH THE EARLY EVENING HOURS. 
REALLY DIFFICULT TO TIME EVERYTHING...SAFE TO SAY AVIATION 
CONDITIONS TODAY WILL BE HIGHLY VARIABLE...WITH IFR CONDITIONS IN 
THE HEAVIER PRECIP. COULD NOT RULE OUT THUNDER TODAY...BUT COVERAGE 
WILL BE LIMITED AND EMBEDDED IN WIDESPREAD PRECIP. THERE WILL BE 
WIND SHIFT LATE TONIGHT AS THE FRONT PUSHES TO THE COAST.

EXTENDED OUTLOOK...PRECIP ENDING NEAR THE COAST LATE TONIGHT WITH 
THE COLD FRONT PUSHING TO THE COAST THURSDAY MORNING WITH GUSTY WEST 
WINDS. VFR FRIDAY AND SATURDAY. RAIN RETURNING SUNDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 AM WEDNESDAY...THE COASTAL FRONT/WARM FRONT HAS FINALLY 
PUSHED ONSHORE WITH SOUTHEASTERLY WINDS SHOWING UP AT MOST BEACHES 
AND BUOYS. THE AIRMASS PUSHING ONSHORE IS TROPICAL WITH DEWPOINTS 
AROUND 70 AND AIR TEMPERATURES IN THE MID 70S COMING OFF THE GULF 
STREAM. WITH NEARSHORE OCEAN WATER TEMPERATURES IN THE LOWER TO 
MIDDLE 50S...SIGNIFICANT COOLING OF THE THIN BOUNDARY LAYER WILL 
RESULT IN DENSE SEA FOG LASTING MOST OF THE DAY. FOG COULD CONTINUE 
INTO THIS EVENING BUT SHOULD END COMPLETELY AFTER MIDNIGHT AS WINDS 
VEER WESTERLY WITH AN APPROACHING COLD FRONT AND MUCH DRIER AIR 
ADVECTS OFFSHORE.

WE ARE CURRENTLY IN A LULL WITH SHOWER ACTIVITY...HOWEVER UPSTREAM 
RADARS AND MODEL DATA INDICATE SHOWERS AND EMBEDDED THUNDERSTORMS 
SHOULD REDEVELOP ACROSS THE AREA THIS MORNING. ACTIVITY MAY TAPER 
OFF AGAIN DURING THE MID TO LATE AFTERNOON HOURS...WITH A SECOND 
WAVE OF SHOWERS AND STORMS EXPECTED THIS EVENING. THE ACTUAL COLD 
FRONT ITSELF WILL PUSH ACROSS THE WATERS SHORTLY AFTER MIDNIGHT... 
PERHAPS ACCOMPANIED BY ONE FINAL LINE OF SHOWERS. 

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...COLD FRONT WILL SHIFT FARTHER OFF SHORE ON 
THURS AS HIGH PRESSURE BUILDS UP FROM THE GULF COAST. GUSTY W-SW 
WINDS EARLY THURS WILL VEER AROUND BECOMING WEST THROUGH THE DAY. 
SEAS UP AROUND 5 TO 7 FT SHOULD FALL BELOW SCA THRESHOLDS BY THURS 
AFTN WITH HIGHEST SEAS GETTING PUSHED FARTHER OFF SHORE IN STRONGER 
W-NW FLOW BEHIND FRONT. WINDS WILL VEER FURTHER TO THE NW AND 
LIGHTEN UP LATE THURS INTO FRI AS CENTER OF HIGH SHIFTS CLOSER 
OVERHEAD. SEAS WILL BE DOWN TO 2 TO 4 FT BY THURS NIGHT AND DOWN TO 
3 FT OR LESS THROUGH FRI AS HIGH PRESSURE MOVES OVERHEAD WITH MORE 
VARIABLE WINDS EXPECTED.

LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 330 AM WEDNESDAY...HIGH PRESSURE WILL SHIFT FARTHER OFF
SHORE ON SATURDAY WITH A RETURN FLOW S-SW 10 KTS OR LESS SETTING
UP. A COLD FRONT WILL DROP SOUTH SUN WITH POSSIBLE WEDGE
DEVELOPING WITH WINDS VEERING AROUND TO THE N-NE AS IT DROPS SOUTH
SUN NIGHT. THIS WILL PUSH SEAS UP A BIT BUT OVERALL BUT EXPECT
SEAS TO GENERALLY 3 FT OR LESS THROUGH THE PERIOD.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ250-252-
     254-256.

     SMALL CRAFT ADVISORY UNTIL NOON EST THURSDAY FOR AMZ250-252-
     254-256.

&&

$$

NEAR TERM...TRA
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...43