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000
FXUS62 KILM 112003
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
303 PM EST WED DEC 11 2013

.SYNOPSIS...
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HIGH PRESSURE WILL CONTINUE TO DOMINATE OUR WEATHER THROUGH FRIDAY.
A DRY COLD FRONT WILL MOVE THROUGH TONIGHT WITH A REINFORCING SHOT
OF COLD AND DRY AIR. THE WEEKEND IS LOOKING TO BE UNSETTLED AS A
STORM SYSTEM TRACKS ACROSS THE SOUTHEAST BRINGING RAIN TO THE
REGION LATE SATURDAY INTO SUNDAY MORNING. COOLER AND DRIER
CONDITIONS ARE EXPECTED EARLY NEXT WEEK.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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AS OF 2 PM WEDNESDAY...HIGH PRESSURE ALMOST DIRECTLY OVERHEAD
WILL WEAKEN THROUGH TODAY BEFORE A REINFORCING SHOT OF COLD AIR
WILL ARRIVE OVERNIGHT AS CLIPPER SYSTEM MOVES ACROSS THE
NORTHEAST. THE CENTER OF THE HIGH IS ORIENTED FROM SW TO NE AND
THEREFORE WINDS WILL COME AROUND BECOMING MORE ON SHORE THROUGH
THIS AFTERNOON INTO THIS EVENING. THE ONLY REAL EFFECT THIS WILL
HAVE ON OUR WEATHER IS A SLIGHT PUSH OF HIGHER DEWPOINT AIR OVER
MAINLY COASTAL AREAS AS WINDS WILL LIGHTEN THROUGH TODAY. OVERALL
SUNNY AND COOL WEATHER WILL CONTINUE THROUGH TODAY. WITH A COLD
AIR MASS ALREADY IN PLACE...TEMP ADVECTION WILL REMAIN FAIRLY
NEUTRAL WITH TEMPS JUST MAKING IT INTO THE 50S FOR A FEW HOURS
THIS AFTERNOON UNDER FULL DECEMBER SUN...RUNNING OVER 5 DEGREES
BELOW NORMAL. A FEW CLOUDS MAY CREEP INTO THE GRAND STRAND AREA AS
WEAK LIFT BUILDS UP FROM THE SOUTH.

BY TONIGHT A STRONG AREA OF HIGH PRESSURE WILL BUILD EAST FROM THE
CENTRAL STATES AS A BROAD MID TO UPPER TROUGH EXTENDING DOWN FROM
THE GREAT LAKES PUSHES A DRY COLD FRONT EAST. THIS WILL MOVE
THROUGH AROUND MIDNIGHT TONIGHT WITH REINFORCING SHOT OF COOL AIR
BEHIND IT. THE SFC BOUNDARY WILL PROVIDE A SHALLOW PUSH OF COOLER
AIR AT FIRST BUT AS THE MID TO UPPER TROUGH AXIS REACHES THE
COASTAL CAROLINAS TOWARD MORNING...A DEEP N-NW FLOW OF COLD AND
DRY AIR WILL SET UP BEHIND IT. THEREFORE INITIALLY THERE WILL BE
MORE RADIATIONAL COOLING AS ATMOSPHERE DECOUPLES UNDER CALM WINDS
AND CLEAR SKIES THIS EVENING. EXPECT TEMPS TO DROP OUT AFTER
SUNSET...QUICKLY DROPPING INTO THE 30S BY MIDNIGHT. AS MID TO
UPPER TROUGH PUSHES DRY COLD FRONT THROUGH AFTER MIDNIGHT THE
WINDS WILL PICK UP WITH CAA TO FOLLOW. THIS WILL HELP TEMPS
STABILIZE AT FIRST BEFORE DEEPER COOLER AIR MAKES ITS WAY IN
TOWARD MORNING. AS MID TO UPPER TROUGH APPROACHES MAY SEE A FEW
MID TO HIGH CLOUDS AROUND THROUGH THE EARLY MORNING HOURS BUT
OVERALL EXPECT MOSTLY CLEAR SKIES AND CAA THROUGH THE EARLY
MORNING HOURS WITH LOW TEMPS SIMILAR TO THIS MORNING...30 TO 35
MOST PLACES WITH COOLER READINGS WELL INLAND AND IN TRADITIONALLY
COOLER PLACES.
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&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
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AS OF 3 PM WEDNESDAY...SURFACE HIGH WILL CONTINUE TO BUILD INTO
THE REGION FROM THE WEST THROUGH FRIDAY ADVECTING A COLDER AIR
MASS INTO THE REGION. DESPITE SUNNY CONDITIONS TEMPERATURE WILL
STRUGGLE TO CLIMB OUT OF THE 40S ACROSS THE INLAND AREAS AND WILL
STAY AROUND 50 ALONG THE COAST. THE HIGH SETTLES OVER THE EASTERN
PORTION OF NC AREA BY FRIDAY AFTERNOON BEFORE SHIFTING OFF THE
COAST FRIDAY NIGHT. WITH THE HIGH OVERHEAD FRIDAY MORNING AND
LIGHT SURFACE WINDS MORNING LOWS WILL DIP INTO THE LOWER TO MID
20S ACROSS MUCH OF THE AREA WITH ISOLATED LOCATIONS IN THE UPPER
TEENS.

CLOUDS START TO ROLL IN IN EARNEST ACROSS THE AREA LATE FRIDAY
MAINLY AFTER 00Z FROM THE SW. HAVE NO POPS IN THE FORECAST OR QPF
THROUGH 12Z. STAYED CLOSED TO ALL GUIDANCE WITH TEMPS AND POPS
THROUGH THE PERIOD.
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&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
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AS OF 3 PM WEDNESDAY...VERY WET TO START THE PERIOD AS A LOW
PRESSURE SYSTEM MOVES UP THE COAST JUST WEST OF THE LOCAL
AREA...BEFORE STRENGTHENING OFFSHORE THE MID-ATLANTIC INTO SUNDAY.

GUIDANCE IN DECENT AGREEMENT THAT THE SAT-SUN TIME FRAME WILL BE VERY
UNSETTLED HERE LOCALLY. SOUTHERN STREAM SHORTWAVE OVER TX AT THE
START OF THE PERIOD EJECTS A PIECE OF ENERGY INTO THE MID-ATLANTIC
DURING SATURDAY...HELPING TO SPAWN SURFACE CYCLOGENESIS ACROSS THE
CENTRAL CAROLINAS. THIS SURFACE LOW DEVELOPS INTO A RESIDUAL RIDGE
OF HIGH PRESSURE...THUS SOUTHERLY FLOW ABOVE THIS HIGH LEADS TO AN
ISENTROPIC UPGLIDE EVENT BEGINNING SATURDAY MORNING. STRENGTHENING
LOW-LEVEL SW FLOW (850MB V-WINDS INCREASE TO +2 SD`S) ADVECTS
TREMENDOUS MOISTURE INTO THE AREA...AND STRATIFORM RAIN WILL
OVERSPREAD THE AREA FROM SW TO NE SATURDAY. THIS RAIN WILL GRADUALLY
BECOME HEAVIER THROUGH THE DAY. THE HEAVIEST RAIN IS EXPECTED
SATURDAY NIGHT AS THETA-E ADVECTION PEAKS...DIFFLUENCE INCREASES
BENEATH A 160KT UPPER JET...AND WEAK INSTABILITY DEVELOPS (ALTHOUGH
IT IS CLEARLY NOT SURFACE BASED). THIS COULD SUPPORT A PERIOD OF
CONVECTIVE RAINFALL SAT NIGHT EMBEDDED WITHIN WHAT WILL OTHERWISE BE
STRATIFORM. AS THE MID-LEVEL TROUGH HANGS BACK INTO SUNDAY...700MB
FLOW REMAINS ORIENTED DIRECTLY FROM THE GULF OF MEXICO...AND PERIODS
OF RAIN MAY PERSIST INTO SUNDAY AFTN BEFORE RAPID DRYING OCCURS
BEHIND THE COLD FRONT. WPC PAINTS WIDESPREAD 1-1.5 INCHES OF
LIQUID...AND FEEL THIS IS PROBABLE AT THIS POINT...BUT WILL NOT
SETTLE ON DETAILS SINCE IT IS STILL SO FAR OUT. TEMPS THROUGH THE
WKND WILL HAVE LIMITED DIURNAL RANGE DUE TO CLOUDS AND RAIN...WITH
HIGHS SLIGHTLY ABOVE CLIMO...AND LOWS WELL ABOVE. MUCH COOLER TEMPS
BY SUNDAY NIGHT HOWEVER AS DRY AND COLD ADVECTION OCCURS.

MON-WED...MID-LEVEL FLOW FLATTENS AND CANADIAN HIGH PRESSURE SETTLES
SOUTH INTO THE CAROLINAS. THIS WILL CREATE A PERIOD OF TRANQUIL
EARLY-WINTER WEATHER WITH HIGHS AND LOWS NEAR CLIMATOLOGICAL NORMS
AND ABUNDANT SUNSHINE.
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&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...NO CLOUDS ON SATELLITE IMAGERY THIS AFTERNOON AS HIGH
PRESSURE DOMINATES OUR WEATHER. VFR WILL PERSIST THROUGH THE DAY
WITH NORTHEAST WINDS BECOMING MORE EASTERLY LATER THIS AFTN...
REMAINING AOB 10 KTS. EXPECT CLEAR AND CALM CONDITIONS TONIGHT WITH
A BIT OF MID/HIGH CLOUD COVER MOVING IN EARLY THURSDAY ASSOCIATED
WITH A DRY COLD FRONT. GUSTY NORTHERLY WINDS WILL ACCOMPANY THIS
SURGE OF COLD AIR...WITH SUSTAINED WINDS 8-12 KTS AND GUSTS OF 15-20
KTS AFTER 12Z THURSDAY.

EXTENDED OUTLOOK...VFR THROUGH FRIDAY. INCREASING CLOUDS SATURDAY
WITH SHOWERS AND MVFR/IFR SATURDAY INTO SUNDAY. VFR ON MONDAY.

&&

.MARINE...
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NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...HIGH PRESSURE WILL WEAKEN OVER THE WATERS
THROUGH TODAY BEFORE A STRONGER AREA OF HIGH PRESSURE BUILDS IN
FROM THE WEST BY THURS. EXPECT NORTHEASTERLY WINDS BECOMING MORE
ON SHORE THROUGH THIS AFTERNOON AS CENTER OF HIGH ORIENTS ITSELF
FROM SW TO NE ACROSS THE CAROLINAS. WINDS WILL REMAIN GENERALLY IN
THE 10 TO 15 KT RANGE...WITH A SLIGHT WEAKENING THROUGH THIS
EVENING. AS WINDS DIMINISH...SEAS WILL SUBSIDE TO 2 TO 3 FT
THROUGH THIS EVENING.

A MID TO UPPER TROUGH WILL PUSH A DRY COLD FRONT THROUGH JUST
AFTER MIDNIGHT. THIS WILL PRODUCE AN INCREASE IN N-NW WINDS UP TO
20 KTS INTO THE EARLY MORNING HOURS. SEAS WILL BEGIN A RISING
TREND AT THAT TIME MAKING THEIR WAY BACK UP TO TO 3 TO 4 FT IN
SURGE THROUGH THE MORNING. SEAS SOUTH OF CAPE FEAR WILL REMAIN
LOWER DUE TO THE NORTHERLY FLOW.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...BRISK NORTHWEST FLOW WILL OF 15 TO 20 KTS
WILL PREVAIL THURSDAY AND THURSDAY NIGHT WITH SEAS RUNNING ABOUT
2-4 FEET. WINDS GRADUALLY DECREASE THURSDAY NIGHT...DROPPING TO
10 KT BY FRIDAY MORNING AND LESS THAN 10 KTS BY FRIDAY AFTERNOON
AS THEY VEER AROUND TO THE NORTHEAST AS SURFACE HIGH MOVES TO THE
NC COAST. GRADIENT REMAINS WEAK INTO FRIDAY NIGHT WITH A MORE EAST
TO SE WIND COMPONENT AT 10 KT OR LESS THROUGH THE END OF THE
PERIOD. SEAS FALL TO 2 FT FRI AND FRI NIGHT.

LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...LOW PRESSURE DEVELOPING ACROSS THE
SOUTHEAST WILL MOVE WEST OF THE AREA SATURDAY...EXITING OFFSHORE
THE MID-ATLANTIC ON SUNDAY. THIS LEAVES INCREASING SOUTHERLY WINDS
THROUGH SATURDAY...BECOMING 15-20 KTS SAT NIGHT...AND THEN
REMAINING AT THOSE SPEEDS WHILE VEERING TO THE SW THEN W ON SUNDAY
AS THE LOW DEPARTS TO THE NE. THESE WINDS THEN SHIFT TO THE NORTH
LATE SUNDAY INTO MONDAY AND DECREASE TO 10-15 KTS AHEAD OF AN
ADVANCING HIGH PRESSURE. THROUGH THE PERIOD...SEAS WILL BE
PRIMARILY DRIVEN BY A 5-6 SEC WIND WAVE...SHIFTING FROM SOUTH TO
SOUTHWEST THROUGH THE WKND...AND RISING TO 4-7 FT LATE SAT AND
SUN...LIKELY PROMPTING A SMALL CRAFT ADVISORY. SEAS DROP BELOW SCA
THRESHOLDS SUNDAY NIGHT...AND FALL FURTHER TO 2-4 FT ON MONDAY.
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&&

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

&&

$$
SYNOPSIS...MAC
NEAR TERM...RGZ
SHORT TERM...MAC
LONG TERM...TRA
AVIATION...RGZ/BJR
MARINE...JDW/RGZ/MAC