-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 042353
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
653 PM EST WED DEC 4 2013

.SYNOPSIS...
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A WARM AND HUMID AIRMASS WILL BEGIN TO MOVE INTO THE
AREA...ALLOWING FOR DENSE FOG TO DEVELOP OVERNIGHT. ABOVE NORMAL
TEMPERATURES ARE EXPECTED THURSDAY AND FRIDAY. UNSETTLED WEATHER
IS EXPECTED THIS WEEKEND AND INTO EARLY NEXT WEEK BEHIND A COLD
FRONT MOVING THROUGH ON SATURDAY.
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&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
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AS OF 7 PM WEDNESDAY...STRONGLY CONSIDERING THE ISSUANCE OF A
DENSE FOG ADVISORY AS VISIBILITIES ARE ALREADY DROPPING THROUGHOUT
THE FORECAST AREA AND THERE HAS ALREADY BEEN ONE RELIABLE REPORT
OF DENSE FOG. WILL MAKE DECISION WITHIN NEXT COUPLE OF HOURS AFTER
MONITORING TRENDS FOR A BIT MORE. PREVIOUS DISCUSSION FOLLOWS:

A SOUPY NIGHT IN STORE ACROSS THE EASTERN CAROLINAS AS DIURNAL
COOLING...ABUNDANT LOW-LVL MOISTURE...LIGHT ONSHORE WINDS AND
PARTIAL SKY CLEARING TEAM UP TO BOOST THE FOG POTENTIAL IN THE
HIGH CATEGORY OVERNIGHT. ELEVATED DEWPOINTS OVER THE COOLER SHELF
WATERS MAY ALSO SERVE TO INDUCE SEA-FOG ALONG OR NEAR OUR COASTAL
ZONES INTO EARLY THURSDAY IN A LIGHT S-SSW FLOW. A DENSE FOG
ADVISORY MAY BE NEEDED OVERNIGHT FOR SEVERELY REDUCED
VISIBILITIES.

OTHER THAN VISIBILITY ISSUES AND POTENTIALLY TREACHEROUS DRIVING
CONDITIONS OVERNIGHT INTO DAYBREAK THURSDAY DUE TO THICKENING AND
EXPANDING FOG DEVELOPMENT...THE WEATHER WILL REMAIN TEPID AND
SOPPY BUT OVERALL QUIET TONIGHT...WITH NO MENTIONABLE POP VALUES.
LOW CLOUD CEILINGS AND FOG LATE TONIGHT SHOULD BRING THE
EQUIVALENT OF MOSTLY CLOUDY CONDITIONS AFTER 6Z MOST AREAS.

LOFTY MINIMUM TEMPERATURES ARE EXPECTED OVERNIGHT IN THE BALMY
REGIME...RUNNING ONLY A FEW DEGREES BELOW THE AVERAGE HIGH FOR
EARLY DECEMBER...WITH READINGS SETTLING IN THE MIDDLE AND UPPER
50S BY DAYBREAK THURSDAY AND AROUND 60 AT THE IMMEDIATE COAST.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...WARM AND HUMID CONDITIONS WILL OVERTAKE THE
AREA THURSDAY THROUGH FRIDAY NIGHT AS THE AREA BECOMES WELL
SITUATED IN THE WARM SECTOR BETWEEN BERMUDA HIGH...ATYPICAL FOR
THIS TIME OF YEAR...TO THE EAST AND AN APPROACHING COLD FRONT
PROGGED TO STALL ACROSS THE APPALACHIAN MOUNTAINS TO THE WEST.
WITH AN ELONGATED UPPER LEVEL TROUGH ON THE WEST
COAST...DOWNSTREAM WE HAVE A STRONG RIDGE IN PLACE...AND IT IS
THIS FEATURE THAT WILL INHIBIT THE FORWARD PROPAGATION OF THE COLD
FRONT DURING THE PERIOD.

AS SOUTHWEST RETURN FLOW CONTINUES...LATEST GUIDANCE AND FCST
SOUNDINGS ARE IN GOOD AGREEMENT OF THE PROJECTED WARM AND MOIST
AIRMASS TO BE IN PLACE AS PWAT VALUES CLIMB TO NEAR 1.50 INCHES ON
THURSDAY. THOUGH MOISTURE WILL BE IN PLACE...NECESSARY LIFTING
MECHANISMS WILL FALL JUST SHORT OF THE AREA AND LATEST FCST
SOUNDINGS ILLUSTRATE DRY MID-LEVELS IN PLACE AS WELL...THUS HAVE NOT
INTRODUCED ANY MENTIONABLE POP FOR THIS PACKAGE. DO NOT EXPECT MUCH
IN THE WAY OF SUNSHINE AS CIRRUS WILL OVERSPREAD THE AREA THROUGH
THE PERIOD. WINDS WILL REMAIN AOB 10 KTS...INCREASING SLIGHTLY INTO
FRIDAY AS THE PRESSURE GRADIENTS TIGHTENS AHEAD OF THE FRONT.

AFTER A FEW WEEKS OF BACK AND FORTH ABOVE/BELOW AVERAGE
TEMPERATURES...WE WILL SHIFT INTO ABOVE NORMAL TEMPERATURES
CATEGORY FOR EARLY DECEMBER. AVERAGE LOW AND HIGH TEMPERATURES FOR
DEC 5TH/6TH IS UPPER 30S/LOW 60S RESPECTIVELY. ON
THURSDAY...TEMPERATURES IN THE MORNING WILL START AROUND
AVERAGE...QUICKLY CLIMBING INTO THE MID/UPPER 70S...WITH LOWS ONLY
DROPPING APPROXIMATELY 10 DEGREES TO LOW TO MID 60S. THIS WOULD MAKE
THURSDAY NIGHT LOWS REMAINING ABOVE AVERAGE HIGH TEMPERATURES.
FRIDAY...WE WILL WARM UP EVEN MORE WITH HIGHS IN THE UPPER 70S
INLAND...POSSIBLY NEAR 80...AND SLIGHTLY COOLER ALONG THE COAST IN
THE MID 70S.

THE BIGGEST WEATHER PHENOMENA OF INTEREST IN THIS FORECAST
PERIOD WILL BE THE ANTICIPATION OF SEA FOG. WITH THE COMBINATION OF
COOLER WATER TEMPERATURES /MID TO UPPER 50S/...DEWPOINTS IN THE
60S...HIGH TEMPS IN THE 70S...AND SOUTH-SOUTHWEST/ONSHORE
FLOW...WOULD ANTICIPATE SEA FOG TO ADVECT ACROSS THE WATERS AND
POSSIBLY ONSHORE. CONFIDENCE IS FAIRLY MODERATE ATTM.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...THE EXTENDED FORECAST LOOKS MOSTLY INTACT
WITH THE LATEST GUIDANCE AS THE CHALLENGES WILL BE MANY WITH A
LITANY OF FACTORS AT PLAY.

FIRST THE BROAD MID LEVEL TROUGHING WILL LEAD TO A COLD AIR DAMMING
EVENT STARTING SATURDAY AND CONTINUING THROUGH SOMETIME MONDAY. THE
FORCING FOR QPF FOR THIS SCENARIO LOOKS WEAK AND SHALLOW AND WOULD
EXPECT MORE OF A LOW CEILING SCENARIO WITH INTERVALS OF DRIZZLE AND
LIGHT RAIN. THE WEDGE BREAKS MONDAY AND DEPENDING ON THE TIMING...A
NON DIURNAL TEMPERATURE CURVE COULD BE IN ORDER SUNDAY NIGHT INTO
MONDAY MORNING. THE MAIN FRONT...WITH A WEAK WAVE DEVELOPING ALONG
IT EARLY TUESDAY SLOWING ITS PROGRESS MOVES ACROSS LATER TUESDAY.

THE HIGHEST POPS...ALTHOUGH NOT EXPECTED TO PRODUCE MUCH IN THE WAY
OF QPF ARE NOW SLATED FOR SATURDAY. THE FRONT TUESDAY WITH THE
BROADNESS OF THE TROUGH DOESN/T GET THE GOOD ATLANTIC TAP AND I
WOULD ENVISION A SOMEWHAT BROKEN LINE OF SHOWERS.

TEMPERATURE FORECAST REMAINS ALMOST UNCHANGED WITH A COOL RAW DAY
SUNDAY WARMING UP MONDAY AND PART OF THE DAY TUESDAY COOLING ONCE
AGAIN IN THE WAKE OF THE FRONT WEDNESDAY.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
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AS OF 00Z...CALM WINDS COMBINED WITH DEWPOINTS IN THE UPPER 50S AND
CLEARING SKIES FAVOR FOG ACROSS OUR CWA TONIGHT. VFR/MVFR THIS
EVENING WILL DETERIORATE TO IFR/LIFR OVERNIGHT AS WIDESPREAD FOG AND
STRATUS PLAGUE ALL TERMS. VSBYS ARE ALREADY FLUCTUATING AT KILM AS
THE SKIES CLEAR ALONG THE COAST...WHILE THE MVFR CIGS INLAND MAY
DELAY THE ONSET OF DENSE FOG A BIT AT KFLO/KLBT. TIMING IS ALWAYS A
CHALLENGE WITH THESE FOG EVENTS...BUT IT APPEARS KILM/KCRE WILL BE
THE FIRST SITES TO SEE IFR VSBYS GIVEN THE PARTIAL CLEARING WE SAW
EARLIER THIS EVENING. AFTER MIDNIGHT...EXPECT IFR/LIFR VSBYS TO
PREVAIL AT ALL SITES WITH 200-400FT CIGS DEVELOPING AS WELL. VSBYS
COULD CERTAINLY DROP BELOW 1/4SM AT TIMES...MOST LIKELY IN THE
08-12Z RANGE. FOG/STRATUS MAY LINGER UNTIL 14-15Z...BUT ONCE IT
DISSIPATES VFR SHOULD PREVAIL ACROSS THE AREA WITH S-SW WINDS AOB 10
KTS.

EXTENDED OUTLOOK...IFR FOG/STRATUS FRIDAY MORNING. RAIN AND MVFR/IFR
CONDITIONS POSSIBLE SATURDAY AND SUNDAY WITH A COLD FRONT. CHANCE OF
RAIN ON MONDAY.
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&&

.MARINE...
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NEAR TERM /THROUGH TONIGHT/...
AS OF 7 PM WEDNESDAY...LATEST OBS SHOW BENIGN CONDITIONS CONTINUE
ACROSS THE WATERS...WITH 2 TO 3 FT SEAS AND LIGHT SW WINDS. NO
CHANGES TO THE FORECAST WITH THE LATEST UPDATE. PREVIOUS
DISCUSSION FOLLOWS:

RELATIVELY FRIENDLY CONDITIONS EXPECTED ON THE 0-20 NM WATERS
THROUGH DAYBREAK THURSDAY WITH LIGHT S-SW WINDS OVERNIGHT AND SEAS
3 FEET OR LESS. THE SEA SPECTRUM WILL BE MADE UP OF S WAVES 1-2
FEET IN 5-6 SECOND INTERVALS COMBINED WITH E WAVES 1 FOOT IN 9-10
SECOND WAVE PERIODS. NO TSTMS ARE ANTICIPATED ON THE 0-20 NM
WATERS...BUT POCKETS OF THICK SEA FOG MAY PLAGUE OUR WATERS INTO
EARLY THURSDAY AS MILD AND MOIST AIR PUSHES NORTHWARD OVER OUR
COOL SHELF AND INSHORE WATERS. VSBYS MAY BE REDUCED AT TIMES TO
BELOW A HALF MILE. A DENSE FOG ADVY MAY BE NEEDED LATE TONIGHT FOR
THE COASTAL WATERS.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...WITH AN ATYPICAL BERMUDA HIGH FOR THIS
TIME OF YEAR PERSISTING...SOUTHWEST FLOW WILL CONTINUE TO PUSH ACROSS
THE WATERS THROUGH THE PERIOD...WITH SUSTAINED WINDS 10-15 KTS ON
THURSDAY WITH SEAS 2-3 FT...BECOMING 15 TO 20 KTS THROUGHOUT THE
DAY ON FRIDAY WITH SEAS INCREASING 3-5 FT.

MAIN CONCERN FOR THIS PERIOD WILL BE THE POTENTIAL FOR SEA FOG GIVEN
THE FAVORABLE CONDITIONS DUE TO WATER AND AIR TEMPERATURES,
SOUTHWEST FLOW AND WARM/HUMID AIRMASS SET TO BE IN PLACE. WOULD NOT
RULE OUT DEVELOPMENT OF DENSE FOG...ESPECIALLY ALONG NEAR-SHORE
PORTIONS OF AMZ252 AND AMZ254.

LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...WIND SHIFT FROM THE SOUTHWEST TO THE
NORTH/NORTHEAST WILL OCCUR MIDDAY SATURDAY...PRETTY MUCH UNCHANGED
FROM THIS TIME YESTERDAY. THE NORTHEASTERLY FLOW WILL CONTINUE
THROUGH MUCH OF THE DAY SUNDAY AND START TO TURN MORE FROM THE
SOUTHEAST LATE AS A COASTAL TROUGH DEVELOPS AND THE WEDGE RELENTS.
SPEEDS DURING THIS TIME WILL BE HOVERING AROUND 15 KNOTS. A
SOUTHWEST FLOW WILL BE FIRMLY BACK IN PLACE BY MIDDAY MONDAY WITH
SPEEDS OF 15-20 KNOTS. SEAS WILL GENERALLY AVERAGE 2-4 FEET
THROUGHOUT THE PERIOD.
-- End Changed Discussion --

&&

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

&&

$$

SYNOPSIS...SGL
NEAR TERM...MJC/REK
SHORT TERM...SGL
LONG TERM...SHK
AVIATION...BJR
MARINE...MJC/REK/SHK/SGL