Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 220819
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
419 AM EDT FRI AUG 22 2014

.SYNOPSIS...
TODAY WILL BRING YET ANOTHER DAY OF UNSEASONABLE HEAT AND HUMIDITY.
SOME RELIEF MAY COME WITH A COLD FRONT ON SATURDAY BUT THE RETURN
OF TRUE SEASONABLE WEATHER PROBABLY WON`T BE UNTIL SUNDAY. MUCH
OF THE UPCOMING WEEK LOOKS SEASONABLE AND RAIN-FREE.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM FRIDAY...PLENTY OF MID AND UPPER LEVEL CLOUDS ACROSS
THE FA AT THE MOMENT. THIS WILL LIKELY KEEP MINIMAL FOG DEVELOPMENT
AND COVERAGE FOR EARLY THIS MORNING.

AMPLIFYING MID-UPPER RIDGE TO OCCUR THIS PERIOD...WITH ITS AXIS
EXTENDING FROM THE CENTRAL GULF COAST STATES TO THE WESTERN GREAT
LAKES...BASICALLY ALONG THE MISSISSIPPI RIVER VALLEY. AT THE SAME
TIME...A MID-LEVEL S/W TROF WILL DROP NEARLY DUE SOUTH FROM THE NE
STATES AS THE FLOW ALOFT AMPLIFIES. THIS WILL HELP DRIVE A SFC COLD
FRONT...AKA BACKDOOR COLD FRONT...TO THE DOORSTEPS OF THE ILM CWA
BY DAYBREAK SATURDAY.

WILL BE DEALING WITH PLENTY OF DEBRIS CLOUDS FROM CONVECTION NORTH
OF THE FA OVERNIGHT AND THIS MORNING. AS THE FLOW ALOFT
AMPLIFIES...THOSE MID-LEVEL IMPULSES IE. VORTS...WILL TAKE AIM AT
THE ILM CWA ESPECIALLY TONIGHT. AS FAR AS POPS THIS PERIOD...WILL
INDICATE A 20-30 POP FROM SEA BREEZE INDUCED CONVECTION THIS
AFTERNOON. FOR LATER TONIGHT ASSOCIATED WITH AN UPPER VORT AND THE
SFC COLD FRONT DROPPING SOUTH...WILL INDICATE A LOW CHANCE POP.

HAVE STAYED CLOSER TO A HIGHER MAX TEMP FORECAST FOR TODAY...WITH
THE GFS MOS GUIDANCE HEAVILY LEANED ON. WITH LOW TO MID 70S
DEWPOINTS...HEAT INDICES WILL REACH 105+ THIS AFTERNOON ACROSS A
SELECT ILM SC COUNTIES. WILL ISSUE AN AFTERNOON HEAT ADVISORY FOR
THOSE COUNTIES. ELSEWHERE...A SPS WILL BE UTILIZED TO CONVEY THE
HEAT THAT DOES NOT MEET HEAT ADV CRITERIA BUT NEVERTHELESS COULD
STILL BE EXTREMELY DANGEROUS IF ONE DOES NOT TAKE THE PROPER
PRECAUTIONS OR STEPS WHEN VENTURING OUTSIDE.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...BACKDOOR COLD FRONT PUSHES THROUGH ON SATURDAY.
MOS NUMBERS ARE GENERALLY SPREAD BY 5 DEGREES WITH THE MAV WARMER OF
THE TWO. HAVE BASICALLY SPLIT THE DIFFERENCE...THE ACTUAL CAA LAGS
AND THE `COOLING` MAY BE MORE A FUNCTION OF FAIRLY EXTENSIVE CLOUD
COVER ASSOC WITH FROPA. MOS POPS ARE SURPRISINGLY LOW
AREA-WIDE...GENERALLY SLIGHT CHANCE TO LOWEST CHANCE RANGE. GIVEN
THE ANTECEDENT WARM AND HUMID AIRMASS IN PLACE PREFER THE 40-ISH
POPS CLOSE TO PREVIOUS FORECAST. MORE SEASONABLE AND LESS HUMID AIR
STARTS CREEPING IN SATURDAY NIGHT INTO SUNDAY. THE MOISTURE HOWEVER
IS SLOWER TO ADVECT OFF TO THE SOUTH. CLOUDS MAY THUS HANG IN ON
SUNDAY AND SOME SLIGHT CHANCE POPS WILL REMAIN IN THE
FORECAST...SLIGHTLY FAVORING COASTAL AND SOUTHERN LOCALES WHICH ARE
CLOSER TO THE BOUNDARY.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...DRYING BECOMES PRONOUNCED ON MONDAY AS HIGH
PRESSURE WEDGE PUSHES FRONT AND ITS ASSOC MOISTURE EVEN FURTHER TO
THE SOUTH. MEANWHILE BUILDING UPPER RIDGE EXPANDS ACROSS MS AND OH
VALLEY REGIONS BRINGING A NORTHERLY FLOW LOCALLY. THIS WILL BE IN
PLACE THROUGH WEDNESDAY AND SOME VERY PLEASANT WEATHER IS EXPECTED.
BOTH RIDGES WEAKEN ON WEDNESDAY WHICH MAY ALLOW SOME LOW LEVEL
MOISTURE RETURN IN THE FORM OF NOTICEABLY MORE HUMID AIR...BUT STILL
TOO SHALLOW TO SUPPORT ANY MEANINGFUL PRECIP CHANCES.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...VFR CONDITIONS MAY GIVE WAY TO PATCHES OF MVFR VSBYS
OVERNIGHT AS CALM AND HUMID CONDITIONS SUPPORT SOME PATCHY MVFR BR.
ELSEWHERE...EXPECT THICKENING MID/HIGH CLOUDS TO KEEP VSBYS FROM
DROPPING BELOW MVFR. VSBYS WILL IMPROVE TO VFR SOON AFTER 12Z WITH
WNW WINDS AROUND 5 KTS THIS MORNING. AS THE SEA BREEZE MOVES
ONSHORE...WINDS ALONG THE COAST WILL BECOME S-SW AROUND 10 KT. NOT
EXPECTING MUCH IN THE WAY OF AFTN CONVECTION OTHER THAN SOME
ISOLATED SEA BREEZE STORMS POSSIBLY DEVELOPING AFTER 18Z. WILL
INCLUDE VCTS FOR THE COASTAL SITES ATTM...EVENTHOUGH CONFIDENCE
IS NOT AS HIGH LIKE PREVIOUS DAYS. THIS MAINLY DUE TO THE
INFLUENCE OF THE UPPER HIGH PRESSURE RIDGE WHICH TENDS TO SUPPRESS
CONVECTION.

EXTENDED OUTLOOK...CHC AFTERNOON/EVENING SHRA/TSRA THROUGH SUNDAY.
EXPECT VFR MON/TUE WITH HIGH PRESSURE OVER THE EAST COAST.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM FRIDAY...A SFC TROF WILL EXTEND N-S ACROSS THE
EASTERN CAROLINAS INTO TONIGHT. RIDGING FROM HIGH PRESSURE
CENTERED WELL OFFSHORE WILL EXTEND TO THE SE STATES...SOUTH OF
THE AREA WATERS. THE 2 COMBINED WILL PRODUCE SW WINDS ACROSS THE
LOCAL WATERS TODAY. FOR TONIGHT...A BACKDOOR COLD FRONT WILL DROP
SOUTH REACHING THE DOORSTEPS AT SURF CITY TOWARD DAYBREAK SAT.
THIS WILL RESULT IN WINDS VEERING TO THE WEST ACROSS THE ILM NC
WATERS LATE TONIGHT. THE SFC PG WILL YIELD A 10 TO OCCASIONALLY 15
KT WIND SPEED. SIGNIFICANT SEAS WILL RANGE BETWEEN 2 AND 3 FT.
SHORT PERIOD WIND DRIVEN WAVES FROM THE SEA BREEZE CIRCULATION
WILL DRIVE THE SIGNIFICANT SEAS. AN UNDERLYING 1 FOOT ESE GROUND
SWELL AT 9 SECOND PERIODS WILL REMAIN IDENTIFIABLE.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...THE COMBINATION OF A SURFACE TROUGH RIGHT ALONG
THE COAST EARLY SATURDAY AND A COLD FRONT SLIDING NORTH TO SOUTH
ACROSS THE REGION WILL LEAD TO A LIGHT WEST WIND THAT SHOULD START
VEERING FIRST OVER NORTHERN ZONES IN THE EVENING AND THEN FARTHER
SOUTH OVERNIGHT. THIS SENSE OF TIMING MAY NEED TWEAKING HOWEVER AS
MODELS ARE HAVING A LITTLE TROUBLE RESOLVING THE TWO BOUNDARIES. AT
LEAST A TURN TO THE NORTH LOOKS CERTAIN BY SATURDAY NIGHT AND A
GRADUAL INCREASE IN WIND SPEED AND THUS WAVE HEIGHTS SHOULD GET
UNDERWAY. SUNDAY WILL BRING A RATHER ATYPICAL NORTHEASTERLY FLOW
WITH A LITTLE BIT OF GUSTINESS AS HIGH PRESSURE BUILDS IN FROM THE
NORTH. SCEC TOUGH TO RULE OUT OVER NORTHERN ZONES.

LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...RATHER UNUSUAL NORTHEASTERLY SURGE OF HIGH
PRESSURE TO CONTINUE THROUGH THE PERIOD WITH LITTLE CHANGE. THE
PERSISTENCE OF THE FETCH IN BOTH TIME AND SPACE COULD LEAD TO SOME
ADVISORY-WORTHY 6 FT SEAS BUT WIND SPEEDS WILL TEND TO STAY
SUB-ADVISORY. ALSO INTERESTING BUT HIGHLY UNCERTAIN IS THE
POSSIBILITY OF TROPICAL SYSTEM WELL OFFSHORE. NO DIRECT IMPACTS
EXPECTED AT THIS POINT BUT ITS RELATED SWELLS COULD BE RADIATING
THIS WAY BY THE END OF THE PERIOD OR JUST BEYOND.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY FROM NOON TODAY TO 6 PM EDT THIS EVENING FOR
     SCZ032-033-039-053>056.

NC...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH/BJR
MARINE...





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