Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 281938
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
338 PM EDT THU AUG 28 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL THROUGH TONIGHT. A BACKDOOR COLD
FRONT WILL DROP TO CENTRAL NORTH CAROLINA BEFORE STALLING LATE
TONIGHT AND FRIDAY. THE FRONT WILL MOVE BACK TO THE NORTH AS A
WARM FRONT DURING THIS WEEKEND. BERMUDA HIGH PRESSURE WILL
STRENGTHEN OVER THE WESTERN ATLANTIC...BRINGING TYPICAL LATE
SUMMER WEATHER TO THE CAROLINAS THROUGHOUT THE LABOR DAY WEEKEND
...AND CONTINUING WELL INTO NEXT WEEK. A LOW CHANCE FOR DAILY
AFTERNOON OR EARLY EVENING SHOWERS OR THUNDERSTORMS WILL RETURN
LATE THIS WEEKEND...AND CONTINUE INTO NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 300 PM THURSDAY...CLEAR SKIES AND INCREASINGLY LIGHT WINDS
EXPECTED ESPECIALLY AFTER SUNSET WITH PIEDMONT TROUGH WEAKENING
AND HIGH PRESSURE CENTERS BOTH TO OUR NORTH AND OUR EAST. WITH
RELATIVELY LOW DEWPOINTS IN PLACE FEEL THAT MOS GUIDANCE NUMBERS
ARE A FEW DEGREES TOO WARM. MOST PLACES WILL GET DOWN INTO THE MID
60S EXCEPT FOR ALONG THE IMMEDIATE COAST WHERE UPPER 60S WILL TEND
TO BE MORE THE RULE.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 300 PM THURSDAY...RIDGING ALOFT AND AT THE SFC WILL DOMINATE
THE SOUTHEAST U.S. COAST THIS PERIOD. MODELS SIMILAR WITH INCREASING
500MB HEIGHTS TO THE MID 590S ACROSS THE CAROLINAS WELL INTO THE
UPCOMING WEEKEND. AT THE SFC...A WEAK BACKDOOR COLD FRONT WILL
DROP AND TEMPORARILY STALL ACROSS CENTRAL NC FRIDAY...THEN MORE
OR LESS DISSIPATE AS IT LIFTS BACK TO THE NORTH THIS WEEKEND.
MODELS THEN HAVE A SFC RIDGE AXIS EXTEND SW FROM A 1025+ HIGH
CENTERED OFF THE NE STATES. THIS RIDGE AXIS WILL EXTEND ACROSS THE
CENTRAL CAROLINAS...RESULTING WITH AND KEEPING AN ONSHORE FLOW
ESE-SSW IN THE LOWER LEVELS ACROSS THE FA DURING THE MAJORITY OF
THIS PERIOD. THIS WILL HELP/AID IN KEEPING THE DAILY HIGHS/MAXES
FROM PUSHING TOO FAR INTO THE 90S. WITH SUBSIDENCE ACCOMPANYING
THE UPPER RIDGING...AND SOMEWHAT LIMITED MOISTURE VIA MODEL
SOUNDINGS AND MODEL TIME HEIGHT DISPLAYS FOR LOCATIONS ACROSS THE
FA...POPS WILL NEARLY BE NON-EXISTANT. EXCEPTION WILL BE ALONG THE
DIURNALLY DRIVEN SEA BREEZE WHERE JUST A 20 POP OR LESS WILL EXIST
DURING THE AFTN/EARLY EVENING...MAINLY STARTING ON SATURDAY. FOR
FRI/SAT MAXES...HAVE TWEAKED LOWER BY 1 TO 3 DEGREES FROM THE
PREVIOUS PACKAGE...MAINLY DUE TO PROGGED ONSHORE FLOW IN THE LOWER
LEVELS. AS FOR MINS...VARIOUS MODEL MOS GUIDANCE SIMILAR WITH ONE
ANOTHER AND SEE NO REASON TO DETOUR FROM THEIR NUMBERS...RANGING
FROM THE UPPER 60S WELL INLAND...TO THE LOW TO MID 70S AS YOU WORK
YOUR WAY EASTWARD TO THE IMMEDIATE COAST.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 300 PM THURSDAY...MID LEVEL RIDGE OFF THE COAST AT THE START OF
THE PERIOD WILL WEAKEN AND FLATTEN...EXPANDING WEST AS IT DOES SO.
THIS WILL LEAVE A RELATIVELY FLAT/PROGRESSIVE MID LEVEL PATTERN OVER
THE SOUTHERN STATES INTO THE END OF NEXT WEEK. SUN AND MON DEEP
SOUTHWEST FLOW ON THE WEST SIDE OF THE MID LEVEL RIDGE WILL PUMP
PLENTY OF GULF MOISTURE OVER THE REGION. PRECIPITABLE WATER VALUES
WILL EXCEED 2 INCHES MON AND HANGING AROUND 2 INCHES THROUGH THE END
OF THE PERIOD. DRY MID LEVELS AND WEAK SUBSIDENCE MAY LIMIT DEEP
CONVECTION ON SUN BUT STARTING MON COVERAGE SHOULD INCREASE WITH SEA
BREEZE AND PIEDMONT TROUGH BECOMING MAIN FEATURES. LATE IN THE
PERIOD A COLD FRONT WILL DROP IN FROM THE NORTH BUT TIMING REMAINS A
QUESTION. ONLY MINIMAL CHANGES PLANNED TO INHERITED GRIDS/FORECAST.
TEMPS WILL RUN NEAR TO ABOVE CLIMO.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...VFR CONDITIONS ARE EXPECTED THROUGH THIS EVENING.
HIGH PRESSURE WILL REMAIN IN CONTROL. SOME CLOUDS TO THE NORTH
ASSOCIATED WITH A WEAK FRONT THAT WILL UNSUCCESSFULLY TRY TO DROP
INTO THE REGION TONIGHT. NO WEATHER WILL BE ASSOCIATED WITH
IT...POSSIBLY A MID CLOUD CEILING. WESTERLY FLOW IS EXPECTED
TODAY...BECOMING SOUTHWEST ALONG THE COAST. LIGHT WINDS TONIGHT.
SOME FOG IS POSSIBLE TOWARD THE END OF THE FORECAST
PERIOD...HOWEVER WINDS AT THE BOUNDARY LAYER MAY BE TOO STRONG.
FRIDAY...MOSTLY SUNNY WITH A WEAK THERMAL TROUGH SETTING UP. THERE
MAY BE AN ISOLATED SHOWER IN THE AFTERNOON.

EXTENDED OUTLOOK...MORNING FOG POSSIBLE SATURDAY. A SLIGHT CHANCE OF
SHOWERS FOR OUR NORTHERN TERMINALS SAT. INCREASING CHANCES FOR
PRECIP SUNDAY THROUGH TUESDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300PM THURSDAY...WAVE PERIODS CONTINUE TO DECREASE AS THE
SWELL ENERGY FROM CRISTOBAL DOES THE SAME. EVEN SO...SEAS
SLIGHTLY HIGHER OVER PENDER/NEW HANOVER ZONES WHERE THE SWELL
ENERGY IS ACTING TO RETARD THE NEARSHORE/OFFSHORE GRADIENT IN WAVE
HEIGHT DESPITE THE OFFSHORE FLOW. IN THESE AREAS SEAS MAY HAVE
TROUBLE FALLING BELOW 3 FT THROUGH THE PERIOD. FARTHER SOUTH THERE
IS WAVE HEIGHT SHADOWING...MOST PRONOUNCED OFF OF BRUNSWICK
COUNTY. SOUTHERNMOST ZONES TO FALL TO JUST 2 FT. WIND-WISE...A
GENERAL SW AT 10 KNOTS EVERYWHERE.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 PM THURSDAY...SFC BACKDOOR COLD FRONT STALLED IN THE
VICINITY OF CAPE HATTERAS DURING FRIDAY...WILL BASICALLY DISSIPATE
AS IT LIFTS BACK TO THE NORTH THIS WEEKEND. SFC RIDGING FROM THE
HIGH CENTERED OFF THE NE STATES WILL BECOME THE DOMINATE FEATURE
TO AFFECT THE AREA WATERS FOR THE REMAINDER OF THIS PERIOD. THE
POSITIONING OF THE SFC RIDGE AXIS ACROSS THE CAROLINAS WILL RESULT
IN AN ONSHORE FLOW...ESE THRU S...ACROSS THE AREA WATERS DURING
THIS 2 DAY PERIOD. THE SFC PG WILL BE IN A RELAXED
MODE...RESULTING WITH WIND SPEEDS AROUND 10 KT...WITH 10-15 KT
DURING THE HEIGHT OF THE DAILY AFTN/EVENG SEA BREEZE CIRCULATION
EACH DAY OF THIS SHORT TERM PERIOD. SIGNIFICANT SEAS WILL RUN 2 TO
3 FT EACH DAY VIA WAVEWATCH3 AND SWAN MODELS...WITH A FEW 4
FOOTERS NOT OUT OF THE QUESTION FROM ANY ROGUE GROUND SWELL
LEFTOVER FROM CRISTOBAL.

LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 300 PM THURSDAY...ELONGATED BERMUDA HIGH AND PIEDMONT TROUGH
WILL MAINTAIN SOUTH TO SOUTHWEST FLOW THROUGH THE PERIOD. SPEEDS
WILL RANGE FROM AROUND 10 KT AT NIGHT TO A SOLID 15 KT IN THE
AFTERNOON WHEN THE TROUGH IS AT ITS STRONGEST. PROLONGED SOUTHERLY
FETCH WILL BUILD SEAS FROM AROUND 2 AT THE START OF THE PERIOD TO
A SOLID 3 FT TUE.

&&

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

&&

$$
SYNOPSIS...DCH
NEAR TERM...MBB
SHORT TERM...DCH
LONG TERM...III
AVIATION...MBB/DL



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