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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 131727
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1227 PM EST FRI DEC 13 2013

.SYNOPSIS...
DRY HIGH PRESSURE WILL SHIFT OFFSHORE TODAY. THE WEEKEND WILL
BECOME UNSETTLED AS A STORM SYSTEM TRACKS ACROSS THE SOUTHEAST
AND INTO THE CAROLINAS...BRINGING RAIN ON SATURDAY INTO EARLY
SUNDAY. COOL AND DRY WEATHER IS EXPECTED MUCH OF NEXT WEEK AS
HIGH PRESSURE BECOMES REINFORCED OVER THE REGION. A STORM SYSTEM
MAY IMPACT THE CAROLINAS NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM FRIDAY...A DAY OF TRANSITION AS A DRY AND COOL AIR
MASS ASSOCIATED WITH CANADIAN HIGH PRESSURE SLIPS OFFSHORE TODAY.
THIS PROCESS WILL BOOST SFC DEWPOINTS THROUGH DAYBREAK SATURDAY.
ALTHOUGH TEMPERATURES WILL FALL INTO LATE AFTERNOON AND EVENING
BY DIURNAL COOLING...THE RETURN FLOW AND ENCROACHING CLOUD COVER
WILL CAUSE MINIMUMS TO BE REALIZED BETWEEN 3Z/10PM-6Z/1AM...MAINLY
DIPPING INTO 40S PERHAPS UPPER 30S WELL INLAND WITH EARLY TEMP-CURVE
DROPS.

RAIN CHANCES THROUGH DAYBREAK SATURDAY REMAIN BELOW MENTIONABLE
VALUES WITH THE EXCEPTION OF THE CAPE FEAR REGION DURING THE PRE
DAWN HOURS INTO SUNRISE AS A COASTAL TROUGH OFFSHORE GENERATING
LOW-LVL CONVERGENCE TRIPS OFF A FEW NORTHWARD MOVING SHOWERS THAT
MAY POTENTIALLY CLIP CAPE FEAR...THUS ISOLATED SHOWERS RETAINED
FOR THE COASTAL ZONES AND THE CAPE FEAR AREA VERY EARLY ON SAT.

NO CHANGES TO MAXIMUMS TODAY...MIDDLE AND UPPER 50S...MILDEST S.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...COASTAL TROUGH WILL BE POISED TO MOVE ONSHORE AS
THE PERIOD BEGINS. LOCATION OF SURFACE LOW UNDER SOUTHERN STREAM
SHORTWAVE THAT EJECTED FROM THE SOUTHWEST SUGGESTS THE TROUGH WILL
BE ABLE TO MAKE A DECENT PUSH INLAND SAT. AS THE TROUGH IS SLOWLY
MOVING INTO THE WEAKENING WEDGE DEEP SOUTHWEST FLOW ALOFT WILL PUMP
PLENTY OF GULF MOISTURE OVER THE SOUTHEAST. FORECAST SOUNDINGS
INCREASE PRECIPITABLE WATERS TO 1.6 INCH LATE SAT...WHICH IS ABOUT 2
STANDARD DEVIATIONS ABOVE NORMAL AND USUALLY AN INDICATOR OF HEAVY
RAIN POTENTIAL.

THE INCREASED MOISTURE SAT AFTERNOON AND SAT NIGHT WILL BE
ACCOMPANIED BY WEAK ISENTROPIC LIFT...A 50+ KT LOW LEVEL
JET...ELEVATED INSTABILITY...AND A 150 KT JET MOVING OVER THE
SOUTHEAST INCREASING DIFFLUENCE ALOFT. THERE WILL ALSO BE SOME LOW
LEVEL CONVERGENCE ALONG A COLD FRONT BEING DRAGGED ACROSS THE
SOUTHEAST LATE SAT NIGHT BY SURFACE LOW EXITING OFF TO THE
NORTHEAST. TOGETHER THESE FACTORS SHOULD LEAD TO LIGHT RAIN
DEVELOPING AROUND MIDDAY SAT THEN BECOMING WIDESPREAD SAT AFTERNOON
AND CONTINUING INTO SAT NIGHT. CANNOT RULE OUT THE POSSIBILITY OF AN
ISOLATED RUMBLE OF THUNDER SAT EVE BUT NOTHING WARRANTING INCLUSION
IN THE FORECAST.

TEMPERATURES SAT AND SAT NIGHT WILL BE TRICKY WITH THE TIMING OF THE
TROUGH MOVING INLAND AND THEN LIFTING NORTH AS WARM FRONT BEING THE
KEY. A WIDE RANGE OF TEMPERATURES ARE EXPECTED WITH MID 60S ALONG
THE COAST TO UPPER 50S INLAND. HOWEVER INLAND AREAS MAY END UP STUCK
IN THE LOW TO MID 40S FOR A GOOD PORTION OF THE DAY BEFORE WARMING
UP LATE. COLD FRONT MOVES ACROSS THE AREA LATE SAT NIGHT FOLLOWED BY
SOME VERY WEAK COLD ADVECTION. LOWS END UP ABOVE CLIMO WITH LOWER
40S WELL INLAND TO LOWER 50S ALONG THE COAST.

SOME LIGHT PRECIP MAY LINGER OVER THE AREA BEYOND 12Z SUN MORNING
BUT SIGNIFICANT RAIN WILL END AROUND DAYBREAK. WILL HOLD ONTO A
TOKEN LOW CHC POP FOR SUN MORNING BUT HAVE VERY LITTLE QPF. DEEP DRY
AIR ABOVE 850 MB WILL MOVE OVER THE AREA IN THE WAKE OF THE
FRONT...WHICH WILL PUSH WELL OFF THE COAST DURING THE DAY AS SURFACE
HIGH BUILDS IN FROM THE WEST. SKIES ARE NOT LIKELY TO CLEAR OUT
QUICKLY THOUGH. MOISTURE REMAINS TRAPPED IN THE LOW LEVELS...KEEPING
CLOUDS AROUND INTO THE AFTERNOON...ESPECIALLY ALONG THE COAST.
STRONGER COLD ADVECTION WILL DEVELOP DURING SUN CAUSING AFTERNOON
TEMPS TO DROP A LITTLE EARLIER THAN WOULD TYPICALLY BE EXPECTED.
HIGHS WILL END UP ABOVE CLIMO BUT LIKELY OCCUR SHORTLY AFTER MIDDAY.
WEAKENING COLD ADVECTION SUN NIGHT WILL DROP LOWS NEAR TO SLIGHTLY
BELOW CLIMO BY THE END OF THE PERIOD.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...PERIOD WILL BE DRY WITH BROAD MID LEVEL
TROUGHING BECOMING MORE PROGRESSIVE BY THE MIDDLE OF THE WEEK. DEEP
DRY AIR REMAINS IN PLACE THROUGH THE END OF THE PERIOD KEEPING
PRECIP CHANCES NEAR ZERO. MODIFYING HIGH PRESSURE IN THE REGION MON
AND TUE WILL BE REINFORCED BY A SECOND AREA OF HIGH PRESSURE WED
INTO THU. GENERALLY TEMPERATURES WILL BE AROUND CLIMO THROUGH THE
PERIOD.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
AS OF 18Z...HIGH CONFIDENCE FOR VFR TO CONTINUE THROUGH
TONIGHT...WITH CONDITIONS GRADUALLY DETERIORATING TO MVFR ON
SATURDAY.

VFR WILL PERSIST THIS AFTERNOON WITH LIGHT EAST-SOUTHEAST
WINDS...GRADUALLY BECOMING SOUTH-SOUTHEAST...AROUND 5 KTS OR
SLIGHTLY HIGHER...AS A HIGH PRESSURE OVERHEAD GRADUALLY PUSHES OFF
TO THE NORTHEAST TODAY. CLOUD COVERAGE WILL BEGIN TO INCREASE THIS
EVENING AS BOTH A COASTAL TROUGH JUST OFFSHORE AND A LOW PRESSURE
SYSTEM MOVING IN FROM THE WEST BEGIN TO AFFECT THE AREA. COULD NOT
ENTIRELY RULE OUT LOWERED CIGS TO CREATE MVFR EARLY SATURDAY
MORNING WITH VCSH...ESPECIALLY ALONG THE COAST...BUT ANTICIPATE
MVFR CIGS AND WIDESPREAD -RA TO OCCUR AFTER DAYBREAK AND CONTINUE
THROUGH THE END OF THE VALID TAF PERIOD. EXPECT EAST-SOUTHEAST
WINDS ON SATURDAY WITH SUSTAINED WINDS AOB 12 KTS.

EXTENDED OUTLOOK...SHOWERS LIKELY WITH PERIODS OF MVFR/IFR
CONDITIONS LATE SATURDAY INTO EARLY SUNDAY. VFR DEVELOPING SUNDAY
AND PERSISTING THROUGH MID-WEEK.
-- End Changed Discussion --

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM FRIDAY...FRIENDLY MARINE CONDITIONS WILL PREVAIL
OVER THE WATERS TODAY AND TONIGHT AS A HIGH PRESSURE SYSTEM OVER
SOUTHEASTERN CONUS MOVES EAST ACROSS THE FORECAST AREA. TONIGHT
A COASTAL TROUGH WILL TIGHTEN OVER THE WATERS ON THE WESTERN
PERIPHERY OF THE HIGH...BRINGING A CHANCE OF RAIN SHOWERS OVER THE
WATERS INTO EARLY SATURDAY. TODAY MARKS A DAY OF TRANSITION FOR
WINDS AS THE HIGH SLIPS OFFSHORE...BECOMING E-SE THIS AFTERNOON
AND SE TONIGHT...PICKING UP TO 15 KT BY DAWN SATURDAY.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...COASTAL TROUGH WILL MOVE ONSHORE SAT MORNING
WITH SOUTHERLY FLOW DEVELOPING ACROSS THE WATERS. GRADIENT
TIGHTENS UP LATER SAT AND SAT NIGHT WITH WIND SPEEDS INCREASING
FROM 15 TO 20 KT SAT TO 20 TO 25 KT SAT NIGHT. FAIRLY CONFIDENT
CONDITIONS WILL REQUIRE SCA FOR AT LEAST SAT NIGHT BUT UNSURE HOW
QUICKLY SCA CONDITIONS WILL DEVELOP SAT AFTERNOON. HAVE LOW
CONFIDENCE FOR TIMING DEVELOPMENT OF SCA CONDITIONS SAT SO AFTER
COORDINATION WITH NEIGHBORING OFFICES WILL HOLD OFF ON ISSUANCE OF
SCA FOR NOW.

COLD FRONT NEAR THE COAST SUN MORNING WILL PUSH EAST OF THE WATERS
BY MIDDAY WITH OFFSHORE FLOW DEVELOPING. GRADIENT BEHIND THE FRONT
IS INITIALLY WEAK WITH SPEEDS DROPPING TO 10 TO 15 KT BY NOON. WEAK
COLD SURGE DEVELOPS SUN NIGHT AND ALONG WITH A MORE DEFINED GRADIENT
WILL PUSH SPEEDS BACK TO 15 TO 20 KT FOR THE END OF THE PERIOD. SEAS
BUILD FROM 2 TO 3 FT SAT MORNING TO 5 TO 8 FT SAT EVENING AND
CONTINUE RUNNING 5 TO 8 FT INTO EARLY SUN. DEVELOPMENT OF WEST AND
THEN NORTHWEST FLOW SUN WILL KNOCK SEAS UNDER 6 FT BY EARLY
AFTERNOON. PERIOD ENDS WITH SEAS 2 TO 4 FT.

LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...NORTHERLY FLOW WILL DECREASE DURING MON AS HIGH
PRESSURE BUILDS IN FROM THE WEST AND GRADIENT WEAKENS. SPEEDS AROUND
15 KT AT THE START OF THE PERIOD WILL DROP TO 10 TO 15 KT BY MON
AFTERNOON. WINDS WILL VEER TO NORTHEAST LATER MON INTO MON NIGHT AS
THE SURFACE RIDGE AXIS ELONGATES AND MOVES EAST. WINDS WILL BECOME
LIGHT AND VARIABLE LATE MON NIGHT WITH SURFACE RIDGE AXIS SHIFTING
OFF THE COAST. LIGHT WEST-SOUTHWEST FLOW ON TUE...AROUND 10
KT...INCREASES TO 10 TO 15 KT TUE NIGHT WITH GRADIENT BECOMING A
LITTLE MORE DEFINED. SEAS WILL DROP FROM 2 TO 4 FT MON TO 2 TO 4 FT
TUE.

&&

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

&&

$$

SYNOPSIS...8
NEAR TERM...8
SHORT TERM...III
LONG TERM...III
AVIATION...SGL