Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 270554
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1254 AM EST SAT DEC 27 2014

.SYNOPSIS...
DRY HIGH PRESSURE WILL MOVE OVERHEAD BEFORE PUSHING OFFSHORE
SATURDAY. RETURN WINDS BEHIND THE HIGH WILL BRING INCREASING
ATLANTIC MOISTURE FOR THE WEEKEND WITH RAIN RETURNING BY SUNDAY.
RAIN CHANCES WILL CONTINUE THROUGH EARLY NEXT WEEK. A COLD FRONT
WILL CROSS THE COAST TUESDAY...FOLLOWED BY DRY HIGH PRESSURE FOR
THE BEGINNING OF THE NEW YEAR.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1253 AM SATURDAY...DEWPOINT DEPRESSION SLOWLY DECREASING
AND PATCHY FOG WITH AREAS OF MIST IN PLACE. CALM WINDS THROUGHOUT
AT THE SURFACE ACCOMPANIED BY VERY WET GROUND MAY RESULT IN THICK
FOG POCKETS INTO THE PRE-DAWN OF SATURDAY. CURRENT FORECAST/GRIDS
ACCOUNTS FOR THIS AND NO CHANGES TO AREAL COVERAGE OF VSBY
RESTRICTIONS AT THIS TIME NEEDED. PREVIOUS DISCUSSION FOLLOWS.


OTHER THAN SOME PASSING THIN CIRRUS AND VERY SHALLOW MOISTURE NEAR
THE SURFACE THE COLUMN IS DRY. HIGH PRESSURE OVER EASTERN NC WILL
SLOWLY SHIFT OFF THE COAST OVERNIGHT. RADIATIONAL COOLING WILL
ALLOW TEMPS TO DROP TO NEAR FREEZING ACROSS THE NORTHERN TIER
ZONES. MINIMAL T-TD SPREAD WILL ALSO SUPPORT PATCHY FOG. NO MAJOR
CHANGES FROM THE AFTERNOON FORECAST.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...BEAUTIFUL LATE-DECEMBER WEATHER TO START THE
WEEKEND...BUT MORE UNSETTLED WEATHER WILL DEVELOP ON SUNDAY.

LARGE UPPER RIDGE CENTERED OFF THE SE FLORIDA COAST WILL MAINTAIN
ITS PRESENCE ON SATURDAY...WITH ABOVE NORMAL THICKNESSES IN PLACE
INTO THE CAROLINAS. SLOW-MOVING SURFACE HIGH PRESSURE BENEATH THIS
FEATURE WILL DRIFT OFFSHORE THROUGH SUNDAY...SETTING UP WARM/MOIST
RETURN FLOW THE SECOND HALF OF THE PERIOD. SATURDAY STILL LOOKS LIKE
A VERY NICE DAY LOCALLY WITH LOTS OF SUNSHINE AND TEMPS WARMING
TOWARDS 65 AWAY FROM THE BEACHES. LATE SATURDAY CLOUD COVER WILL
BEGIN TO OVERSPREAD THE REGION FROM THE WEST...FIRST IN THE FORM OF
CIRRUS DEBRIS...AND THEN LOWERING THANKS TO DEEP SW FLOW SATURATING
THE COLUMN. AT THE SAME TIME...A WEAK SHORTWAVE WILL MOVE JUST WEST
OF THE AREA...CAUSING AN INCREASE IN PRECIP CHANCES...AND SHOWERS
ARE POSSIBLE SATURDAY NIGHT...ESPECIALLY ACROSS THE WESTERN HALF OF
THE CWA. THETA-E RIDGE NUDGES TOWARDS THE AREA SATURDAY NIGHT...BUT
IT IS WEAK...AND TOTAL FORCING IS PRETTY WEAK...SO QPF WILL BE
MINIMAL...AND LOW-CHC POP IS ALL THAT IS WARRANTED. MINS SATURDAY
NIGHT WILL STAY ELEVATED DUE TO CLOUDS AND WARM SURFACE
FLOW...DROPPING ONLY INTO THE UPPER 40S TO AROUND 50.

SUNDAY IS AN INTERESTING DAY AS PRECIP MAY BE ONGOING FIRST THING IN
THE MORNING...AND THEN SHUT OFF FOR A TIME IN THE AFTN. THE MORNING
PRECIP WILL BE RESIDUAL RAINFALL ASSOCIATED WITH THE AFOREMENTIONED
SHORTWAVE AND DEEP SW FLOW...BUT THIS WILL LIKELY SHUT OFF IN THE
AFTN AS SUBSIDENCE PROMOTES DRYING THROUGH A GOOD PORTION OF THE
COLUMN. LATE SUNDAY HOWEVER...PRECIP IS EXPECTED TO RE-DEVELOP AS A
COLD FRONT APPROACHES FROM THE WEST...DRIVEN BY A DAMPENING SOUTHERN
STREAM VORT IMPULSE. ONCE AGAIN...THE THETA-E RIDGE REMAINS
WEAK...AND JET-LEVEL DIFFLUENCE STAYS DISPLACES WEST OF THE
CWA...BUT THE BEST SHOT FOR PRECIP APPEARS TO BE SUNDAY NIGHT WHEN
PWATS RISE TO 1.25 INCHES. WILL BUMP POP TO LOW-END LIKELY IN THE
FAR NW ZONES...AND MAINTAIN INHERITED HIGH-CHC ELSEWHERE. TEMPS ON
SUNDAY WILL BE QUITE WARM AFTER A WARM MORNING LOW AND CONTINUED
WARM ADVECTION. HIGHS WILL RISE TO NEAR 70 IN THE AFTN...WITH LOWS
SUNDAY NIGHT FALLING ONLY INTO THE MID/UPR 50S.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...MONDAY STARTS OUT WITH A COLD FRONTAL BOUNDARY
DRAPED OVER THE CAROLINAS. AMAZINGLY BOTH EXTENDED MODELS GFS AND
EUROPEAN DROP THIS FRONT ACROSS THE FA DURING MONDAY...TO SOUTH AND
EAST OF THE FA BY TUESDAY B4 STALLING. MODELS DO EYE A WEAK
MID-LEVEL S/W TROF THAT SWINGS ACROSS THE SE STATES WITHIN WSW-ENE
FLOW ALOFT. THE 2 MODELS THINK THAT DURING THIS TIME FRAME A WEAK
SFC LOW COULD DEVELOP FROM THIS S/W ON THE FRONT PRIOR TO EXITING
OUT OVER THE ATLANTIC. DYNAMICS REMAIN UNIMPRESSIVE WITH THIS UPPER
S/W TROF...AND NO REAL TAPPING OF GULF OF MEXICO MOISTURE JUST LOW
LEVEL ATLANTIC MOISTURE. THUS WILL KEEP POPS ON THE LOW CHANCE SIDE
THRU TUESDAY PRIOR TO THE COLD FRONT SINKING SOUTH OF THE FA.
MAX/MIN TEMPS PRIOR TO THE CFP ON TUE WILL RUN UP TO 10+ DEGREES
ABOVE NORMAL.

FOR TUE THROUGH THU...MID TO UPPER LEVEL FLOW TO REMAIN SPLIT...WITH
ARCTIC FLOW COMING OUT OF CENTRAL CANADA ACROSS THE GREAT LAKES TO
THE NE STATES. AND FOR THE ILM CWA...MID TO UPPER FLOW WILL MAINLY
BE FROM THE WSW-WNW. HOWEVER...A 1050+ MB HIGH WILL SLIDE OUT OF
CANADA MON TO THE TX GULF COAST BY WED. LOW LEVEL FLOW WILL ENABLE
SOME OF THIS MODIFIED COLD AIR TO FILTER ACROSS THE FA BY WED THRU
THU. MAX/MIN TEMPS FOR WED AND THU WILL ACTUALLY BE RIGHT AT THE
CLIMO NORMS. IT WILL SEEM COLDER DUE TO WELL ABOVE NORMAL TEMPS
LEADING UP TO THE MID-WEEK COLD AIR. NO POPS DURING THIS PERIOD.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...PATCHY MVFR/IFR DUE TO FOG/MIST OVERNIGHT INTO EARLY
DAYBREAK. VFR AFT 13Z AS DRY HIGH PRESSURE REMAINS OVER THE AREA.

CLEAR SKIES AND LIGHT WIND TO PREVAIL THROUGH THE VALID TAF PERIOD
AS HIGH PRESSURE REMAINS ACROSS THE AREA. VFR AND LIGHT WIND INTO
SATURDAY EVENING.

EXTENDED OUTLOOK...PATCHES OF LIGHT RAIN RETURNING SUNDAY THEN
RAIN ON MONDAY VFR AFTERWARD.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1253 AM SATURDAY...LIGHT AND VARIABLE CONDITIONS WILL
PREVAIL AS THE CENTER OF HIGH PRESSURE SLOWLY MIGRATES OVERHEAD
DURING THE OVERNIGHT. SEAS WILL BE AROUND 2 FT ACROSS MOST OF THE
WATERS IN THIS VERY WEAK PRESSURE GRADIENT ENVIRONMENT.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...HIGH PRESSURE OVERHEAD TO START THE PERIOD
WILL MIGRATE OFFSHORE SATURDAY...AND THEN PUSH FURTHER EAST DURING
SUNDAY. THIS ALL OCCURS WHILE A COLD FRONT SLOWLY APPROACHES FROM
THE WEST...SO WHILE THE GRADIENT WILL BE WEAK MOST OF THE WKND...IT
WILL BEGIN TO PINCH LATE ON SUNDAY. NE WINDS THE FIRST PART OF
SATURDAY WILL TRANSITION TO BE LIGHT AND VARIABLE...BEFORE TAKING UP
A SW DIRECTION SATURDAY NIGHT AND ALL OF SUNDAY. SPEEDS WILL BE JUST
5-10 KTS SATURDAY AND SUNDAY...RISING TO 10 KTS OR A BIT HIGHER
SUNDAY NIGHT. SEAS OF 2-3 FT WILL BE COMMON THROUGH THE PERIOD
REGARDLESS OF WIND DIRECTION...BUT WILL BE CHOPPIEST LATE SUNDAY AS
THE WINDS INCREASE.

LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...MONDAY TO START OUT WITH SW-W FLOW AT 10 TO 15
KT AHEAD OF THE COLD FRONT. THE FRONT SHOULD DROP FROM NORTH TO
SOUTH ACROSS THE AREA WATERS LATE MONDAY NIGHT THROUGH TUE. SCEC TO
POSSIBLY SCA CONDITIONS TO DEVELOP AFTER ITS PASSAGE...WITH
NORTHERLY WINDS AT 15 TO POSSIBLY 25 KT THRU THE REMAINDER OF TUE.
SIGNIFICANT SEAS WILL MAINLY BE A COMBINATION OF A 1-3 FOOT NE
GROUND SWELL AT 11-13 SECOND PERIODS...AND LOCALLY PRODUCED 2 TO 4
FT WIND WAVES AT 4 TO 6 SECOND PERIODS. PCPN REMAINS POSSIBLY AHEAD
AND DURING THE COLD FRONTAL PASSAGE.

&&

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

&&

$$

NEAR TERM...SRP/8
SHORT TERM...JDW
LONG TERM...DCH
AVIATION...SGL/8







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