Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 150223
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1023 PM EDT SUN SEP 14 2014

.SYNOPSIS...
A FRONT STALLED ACROSS SOUTHERN GEORGIA WILL RETURN NORTH
MONDAY...ONLY TO BE PUSHED SOUTH AGAIN TUESDAY AS HIGH PRESSURE
BUILDS EASTWARD ACROSS THE PLAINS STATES. THIS HIGH WILL MOVE ACROSS
THE MID-ATLANTIC STATES LATE IN THE WEEK...PROVIDING FALL-LIKE
WEATHER WEDNESDAY THROUGH SATURDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM SUNDAY...IT CERTAINLY FEELS LIKE THE BEGINNING OF FALL.
A FEW MINUTES RECENTLY SPENT OUT IN THE NWS OFFICE PARKING LOT
REVEALS LOW CLOUDS...A COOL NE BREEZE...AND THE FREQUENT CHIRPS AND
"TSEEPS" OF MIGRATING WARBLERS OVERHEAD. THE LATEST FORECAST UPDATE
REMAINS IN GOOD SHAPE AND NO SIGNIFICANT CHANGES ARE PLANNED. I DID
ADD SOME PATCHY DRIZZLE AS SURFACE RELATIVE HUMIDITY CLIMBS BEYOND
90 PERCENT AND CLOUD BASES FALL BELOW 1500 FEET OVERNIGHT. PREVIOUS
DISCUSSION FROM 730 PM FOLLOWS...

CLOUDS WILL PERSIST THROUGH THE NIGHT AS MOISTURE CONTINUES
THROUGHOUT THE 1500-7000 FOOT LAYER. WEAK WARM ADVECTION EXTENDING
DOWN AS LOW AS 925 MB LATE WILL CREATE TRANSITORY PATCHES OF
ISENTROPIC LIFT ALONG THE 300K THETA SURFACE WITH PATCHY LIGHT RAIN
OR SHOWERS POSSIBLE...MAINLY LATE FOR AREAS NORTH OF THE SANTEE
RIVER. BESIDES LOWERING POPS BEFORE MIDNIGHT FOR ALL AREAS MOST
OTHER CHANGES TO THE FORECAST WERE MINOR. PREVIOUS DISCUSSION FROM
300 PM FOLLOWS...

NE SURGE ON THE LEADING EDGE OF CANADIAN HIGH PRESSURE HAS BROUGHT
LOW-LEVEL COOLING AND SUBSTANTIALLY LOWERED DEWPOINT VALUES ACROSS
THE AREA WHILE STABILIZING A COLUMN FROM THE GROUND FLOOR...STILL
CHALKED FULL OF VAPOR CONTENT PER LATEST SATELLITE DERIVED PWAT
SCANS. OVER- RUNNING AND WEAK WAVES OF ISENTROPIC OMEGA WILL LIKELY
BRING -RA/-DZ OR ISOLATED SHOWERS OVERNIGHT TO THE AREA BUT NO REAL
FLOOD THREAT APPEARS TO EXIST DESPITE VERY WET GROUND AND A WET AIR
MASS.

CLOUDS ARE EXPECTED TO REMAIN PLENTIFUL OVERNIGHT IN THIS REGIME
AND TIME HEIGHT DEPICTIONS SHOW MID-LEVEL DRYING LATE TONIGHT WILL
FURTHER LOWER THE PROBABILITIES OF DEEP CONVECTION FOR LARGE
RAINFALL ACCUMULATIONS...THUS PRIMARILY LIGHT PRECIPITATION THROUGH
DAYBREAK MONDAY AND LOW-END CHANCES. HIGHEST POP VALUES TO RESIDE
EXTREME SOUTH AND OFFSHORE. MIN TEMPS WITH CLOUD COVER AND COOL
AIR ADVECTION SHOULD YIELD LOW TO MIDDLE 60S ACROSS MOST OF THE
FORECAST AREA WITH UPPER 60S TO NEAR 70 CLOSER TO THE SEA.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...COLD FRONT TO OUR SOUTH LIFTS BACK TO THE NORTH
WHILE WASHING OUT CONSIDERABLY. THE END RESULT LOCALLY WILL BE A
REBOUNDING OF TEMPERATURES DESPITE A CONTINUATION OF CONSIDERABLE
CLOUDINESS. THE RISE IN HUMIDITY WILL ALSO BE NOTICEABLE. SOME LIGHT
PRECIP MAY ALSO WASH BACK INTO THE REGION FROM SOUTH TO NORTH.
HOWEVER THE COVERAGE AND AMOUNTS MAY BE OVERDONE IN MODEL GUIDANCE
GIVEN THE WEAK NATURE OF ANY FORCING NOT TO MENTION THE LACK OF
APPRECIABLE RADAR RETURNS ACROSS MOST OF THE SOUTHEASTERN U.S. THIS
AFTERNOON. COLD FRONT PREVIOUSLY SLATED FOR A TUESDAY PASSAGE NOW
LOOKS SLOWER DUE IN PART TO A FLAT WAVE OF LOW PRESSURE BUT ALSO DUE
TO THE LOW AMPLITUDE OF THE UPPER TROUGH DRIVING THE BOUNDARY. EVEN
SO THE BEST CHANCE FOR RAIN WILL COME DURING THE DAY IN THE HUMID
PREFRONTAL AIRMASS AND THE COAST SHOULD BE SLIGHTLY FAVORED WHERE
MOISTURE WILL BE A BIT DEEPER. THERE DOES NOT SEEM TO BE A HEAVY
RAIN THREAT GIVEN SOMEWHAT WEAK FORCING AND LARGER STORM MOTION
VALUES THAN THOSE OF RECENT DAYS.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...FRONT WILL BE WELL OFF THE COAST AT THE START OF
THE PERIOD WITH HIGH PRESSURE WEAKLY BUILDING IN FROM THE NORTH.
ALOFT THE 5H TROUGH RESPONSIBLE FOR PUSHING THE FRONT OFFSHORE WILL
STRENGTHEN A BIT...EXTENDING FARTHER SOUTH. LOW LEVEL NORTHEAST FLOW
WED WILL BE REINFORCED THU AS WEAK LOW DEVELOPS ALONG THE STALLED
FRONT AND THEN LIFTS NORTHEAST. ALTHOUGH THE SETUP IS NOT IDEAL THE
NORTHEAST LOW LEVEL FLOW...WEST TO NORTHWEST FLOW ALOFT...AND
LINGERING MOISTURE WILL LEAD TO A WEDGE LIKE SCENARIO. THIS COULD
LEAD TO A PERIOD OF LOW CLOUD AND POSSIBLY LIGHT RAIN IN THE AREA
MID WEEK. THE HIGH SHIFTS TO EASTERN CANADA AND NEW ENGLAND FRI/SAT
SETTING UP A MORE CLASSIC WEDGE PATTERN BUT THE LOW LEVEL MOISTURE
DECREASES AND CLOUDS DECREASE. THE PARENT HIGH MOVES OFF THE NEW
ENGLAND COAST EARLY SUN BUT AN ELONGATED PORTION OF THE HIGH REMAINS
OVER THE CENTRAL CAROLINAS...MAINTAINING NORTHEAST FLOW THROUGH THE
END OF THE PERIOD. CONFIDENCE IN THE MID TO LATE WEEK FORECAST IS
INCREASING AS THE GFS/ECMWF COME INTO BETTER AGREEMENT.

TEMPERATURES WILL BE NEAR TO SLIGHTLY BELOW CLIMO THROUGH THE PERIOD
WITH HIGHS IN THE MID TO UPPER 70S TO LOWER 80S AND LOWS IN THE LOW
TO MID 60S.

BEST PRECIP CHANCES WILL BE EARLY IN THE PERIOD...THOUGH EVEN HERE
PRECIP CHANCES WILL BE LOW. LINGERING LOW LEVEL MOISTURE WED/THU
COULD LEAD TO AN OCCASIONAL PERIOD OF LIGHT RAIN OR DRIZZLE BUT
MEASURABLE PRECIP IS GOING TO BE HARD TO COME BY. THE STALLED FRONT
AND ASSOCIATED LOW ARE LIKELY TO BE TOO FAR OFF THE COAST TO
DIRECTLY IMPACT THE REGION. DO NOT PLAN MUCH IN THE WAY OF CHANGES
TO INHERITED POP FORECAST OF SLIGHT CHC LOW CHC ALONG THE COAST TO
DRY INLAND.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...1-3KFT MVFR CIGS BLANKET OUR CWA THIS EVENING AS LIGHT
N-NE FLOW REINFORCES A SHALLOW LAYER OF COOLER AIR BEHIND THE COLD
FRONT TO OUR SOUTH. THIS PATTERN WILL CONTINUE OVERNIGHT WITH MVFR
CIGS LOWERING TO IFR...ESPECIALLY OVER THE SOUTHERN TERMINALS WHERE
LOWEST CIGS ARE EXPECTED DUE TO THEIR CLOSE PROXIMITY TO THE FRONT.
KFLO AND KCRE/KMYR WILL LIKELY SEE CIGS DROP BELOW 1KFT AFTER 06Z
AND PERSIST THROUGH DAYBREAK MON. TEMPO IFR CIGS CANNOT BE RULED OUT
AT KILM/KLBT...BUT GUIDANCE SUGGESTS 1-2KFT CIGS WILL PREVAIL ACROSS
OUR NORTHERN TAF SITES. WILL NOT INCLUDE ANY IFR FOR KILM/KLBT ATTM.
OTHER THAN A SLIGHT CHANCE OF -RA/DZ...DO NOT ANTICIPATE ANY PCPN
OVERNIGHT. MVFR CIGS MAY PERSIST THROUGH MUCH OF MON MORNING... BUT
CIGS SHOULD IMPROVE TO VFR LEVELS AFTER MIDDAY AS WINDS BECOME MORE
EASTERLY...REMAINING LESS THAN 10 KT.

EXTENDED OUTLOOK...CHANCE OF SHOWERS/TEMPO MVFR TUES AHEAD OF A COLD
FRONT. POST-FRONTAL MVFR CIGS MAY DEVELOP WED AS COOLER AIR WEDGES
INTO THE REGION. OTHERWISE EXPECT VFR THROUGH FRIDAY.

&&

.MARINE...

NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SUNDAY...WIND SPEEDS AND SEAS ARE SIMILAR TO WHAT WAS
OBSERVED THREE HOURS AGO. THIS LATEST FORECAST UPDATE DELAYS THE
IMPROVING TREND BY A FEW HOURS BUT OTHERWISE TRENDS ARE INTACT.
PREVIOUS DISCUSSION FROM 730 PM FOLLOWS...

THE NE SURGE IS ON ITS LAST LEGS WITH RECENT GUSTS STILL REPORTED AS
HIGH AS 14 KNOTS AT BALD HEAD ISLAND AND 19 KNOTS AT THE OFFSHORE
LEJEUNE BUOY. I HAVE ADJUSTED SEAS UPWARD BY ABOUT A FOOT THROUGH
MIDNIGHT FOR AREAS NEAR AND EAST OF CAPE FEAR BASED ON BUOY
OBSERVATIONS...OTHERWISE NO SIGNIFICANT CHANGES. PREVIOUS DISCUSSION
FROM 300 PM FOLLOWS...

NE WIND-SPEEDS SHOULD ABATE SEVERAL KNOTS AS THE SURGE PLAYS OUT BUT
COUNT ON 15 KT OF WIND OVERNIGHT POSSIBLY GOING MORE TO THE N INTO
EARLY MONDAY. SEAS MAINLY 2-3 FEET EXCEPT 3-4 FT NORTH OF CAPE FEAR.
SEAS A MIX OF ENE WAVES 2-2.5 FT EVERY 4-5 SECONDS AND SE WAVES
1-1.5 FT EVERY 8 SECONDS. PATCHY DRIZZLE AND MIST COULD LIMIT VSBYS
EARLY MONDAY...ESPECIALLY NC WATERS. NO ADVISORIES OR CAUTION
STATEMENTS ARE NEEDED FOR TONIGHT.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...WEAKENING/DISSOLVING FRONT TO MAKE FOR SOME VERY
LIGHT WINDS ON MONDAY. INITIALLY NORTH TO NORTHEASTERLY, THEY WILL
THEN TEND TO VEER AS THE DAY WEARS ON, WITH THIS VEER MOST
PRONOUNCED OVER SOUTHERN WATERS. SEAS WILL AVERAGE 2 TO 3 FT HIGHEST
AWAY FROM SHORE. A LIGHT PREFRONTAL SOUTHERLY FLOW WILL GET
ESTABLISHED BY MONDAY NIGHT. THIS FRONT WAS ORIGINALLY SLATED FOR
TUESDAY BUT NOW LOOKS A LITTLE SLOWER AND ALSO TO BE ACCOMPANIED BY
A FLAT WAVE OF LOW PRESSURE DURING ITS TUESDAY NIGHT PASSAGE. BOTH
FACTORS WILL LEAD TO AN OVERALL SLOWER SENSE OF VEERING. A
NORTHEASTERLY FLOW WILL BE ESTABLISHED IT SEEMS BY THE END OF THE
PERIOD. LOCAL SWAN IMPLIED A NEAR ADVISORY LEVEL NE WIND WAVE LATE
IN THE PERIOD. MUCH PREFER THE SUB-SCEC SEAS ADVERTISED IN EARLIER
FORECAST GIVEN THAT POST FRONTAL WINDS SHOULD HAVE TROUBLE EXCEEDING
15KT.

LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY....ANTICIPATE SCA HEADLINES FOR ALL WATERS THROUGH
MUCH OF THE PERIOD. NORTHEAST FLOW IN THE WAKE OF AN EXITING COLD
FRONT WILL STEADILY INCREASE WED AS HIGH PRESSURE BUILDS SOUTH.
WINDS START OUT 10 TO 15 KT BUT BY MIDDAY SHOULD BE A SOLID 15 KT.
WEAK LOW DEVELOPING ON STALLED FRONT COMBINED WITH THE HIGH BUILDING
SOUTH WILL FURTHER PINCH THE GRADIENT LATE WED NIGHT AND THU.
NORTHEAST FLOW WILL INCREASE TO 15 TO 20 KT WITH POTENTIAL FOR A
SOLID 20 KT THU NIGHT. GRADIENT REMAINS TIGHT ON FRI AS HIGH
CONTINUES TO RIDGE DOWN THE COAST WITH NORTHEAST FLOW APPROACHING 25
KT. SEAS START OUT 3 TO 6 FT BUT COULD BUILD TO 7 FT IN PLACES AS
NORTHEAST WINDS INCREASE AND SWELL FROM HURRICANE EDOUARD REACHES
THE WATERS.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR
     NCZ107.

MARINE...NONE.

&&

$$

SYNOPSIS...TRA
NEAR TERM...MJC/TRA
SHORT TERM...MBB
LONG TERM...III
AVIATION...BJR





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