Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 301529
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1130 AM EDT SUN AUG 30 2015

.SYNOPSIS...
MOISTURE FROM THE GULF OF MEXICO WILL BRING INCREASING
COVERAGE OF SHOWERS AND ISOLATED THUNDERSTORMS FOR THE UPCOMING
WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...

AS OF 1030 AM SUNDAY...TODAY`S FORECAST HAS SOME TEMPERATURE BUST
POTENTIAL. NOT ONLY IS IT QUITE CLOUDY BUT 12Z AREA RAOBS SHOW THIS
MOISTURE TO BE THICK AND THEREFORE HARD-PRESSED FOR MANY BREAKS. AS
SUCH TEMPS HAVE BEEN SLOW TO RISE. LOWERED HIGHS BY 2 DEGREES AND
WOULD NOT BE SURPRISED TO HAVE TO DO SO AGAIN. SIMILARLY WE WILL
HAVE DIFFICULTY DESTABILIZING SO REMOVED THUNDER FOR THE NEXT
SEVERAL HOURS.

AS OF 630 AM SUNDAY...MID TO UPPER SOUTHERLY FLOW WILL STRENGTHEN
ACROSS THE FA DURING THIS NEAR TERM PERIOD. THIS IN RESPONSE TO
THE UPPER BERMUDA HIGH CENTERED OFFSHORE FROM THE SOUTHEAST U.S.
COAST...AND THE UPPER LOW OVER THE FLORIDA PANHANDLE THIS MORNING
THAT IS PROGGED TO LIFT TO THE NNE ALONG THE SPINE OF THE
APPALACHIAN MOUNTAINS...REACHING THE NC MOUNTAINS BY DAYBREAK
MONDAY. THE SOUTHERLY FLOW ALOFT FROM THE 2 COMBINED WX
PHENOMENA...WILL BRING COPIOUS AMOUNTS OF GULF OF MEXICO AND
ATLANTIC MOISTURE TO AND ACROSS THE ILM CWA THIS AFTN THRU
TONIGHT. VARIOUS MODEL SOUNDINGS HAVE PWS INCREASING FROM 1.00 TO
1.50 INCHES EARLY THIS MORNING...TO 2.00 TO 2.25 INCHES BY THIS
EVENING THRU MONDAY DAYBREAK. AT THE SFC...THE OLD FRONTAL
BOUNDARY OR NOW JUST A SFC TROF OF LOW PRESSURE...WILL GET DRAWN
BACK TO THE WEST TO THE IMMEDIATE ILM COASTLINE BY TONIGHT. WITH
PCPN CONVECTIVE TRIGGERS NOW AVBL ACROSS THE ILM CWA FROM SFC
CONVERGENCE AND DYNAMICS ALOFT FROM THE UPPER LOW...THE FA WILL BE
LOOKING AT INCREASING POPS TODAY THRU TONIGHT. WILL PEAK IN THE
GOOD CHANCE TO POSSIBLY LIKELY BY LATE THIS AFTN THRU TONIGHT.
WILL ASSIGN THE ATTRIBUTE...HEAVY RAIN POSSIBLE FOR CONVECTION
MAINLY DURING LATE THIS EVENING AND OVERNIGHT. STAYED ON THE LOWER
SIDE FOR MAX TEMPS TODAY DUE TO WIDESPREAD CLOUDINESS AND PCPN
SLOWLY OVERSPREADING THE FA FROM SOUTH TO NORTH. AS FOR TONIGHTS
MINS...STAYED CLOSER TO A WARM/MILD BIAS.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 315 AM SUNDAY...SHAPING UP TO BE A RATHER UNSETTLED COUPLE OF
DAYS AS THE STREAM OF MOISTURE AS SEEN ON INFRARED IMAGERY
EXTENDING DEEP INTO THE TROPICS CONTINUES TO MOVE ACROSS. I HAVE
ELEVATED POPS MAINLY FOR MONDAY TO LIKELY ALONG THE COAST WHERE
THE DEEPEST MOISTURE WILL RESIDE. SOME DRYING IS NOTED IN THE
PROFILES FOR TUESDAY MAINLY IN THE GFS BUT THE NAM REMAINS BULLISH
ON POPS. TO COMPROMISE I DID DECREASE THE POPS SOMEWHAT TUESDAY
BUT STILL ADVERTISING CHANCE VALUES AREA WIDE. I TRIMMED BACK
EXPECTED HIGHS A DEGREE OR TWO MONDAY AND INCREASED THE MORNING
LOWS THE SAME DUE TO THE EXPECTED MOISTURE.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 315 AM SUNDAY...MEDIUM RANGE GUIDANCE CONTINUES TO DEPICT A WEAK
PATTERN BOTH AT THE SURFACE AND ALOFT. THERE REMAINS AMPLE MOISTURE
TO GENERATE CONVECTION AND WITH A SUBTLE PIEDMONT TROUGH AND COASTAL
TROUGH FROM TIME TO TIME...PRUDENT TO KEEP GOOD CHANCE POPS IN THE
FORECAST THROUGH FRIDAY. MODELS DO HINT AT A BACKDOOR FRONT SLIDING
THROUGH SATURDAY WHICH WOULD DRY THINGS OUT. THIS TREND IS REFLECTED
IN THE FORECAST WITH LOWER POPS AND SLIGHTLY LOWER TEMPERATURES.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 12Z...NEEDLESS TO SAY THE NEXT SEVERAL DAYS WILL BE UNSETTLED.
RADAR SHOWS A WAVE OF SHOWERS MOVING UP FROM THE SOUTH. THE HRRR
MODEL HAS THIS DEPICTED...BUT NOT AS STRONG AS IT SHOULD HAVE
INITIALIZED. LOOK FOR PRECIP TO GET INTO THE MYRTLES AND FLO IN A
COUPLE OF HOURS WITH MVFR CEILINGS EXPECTED LATER TODAY. THE COLUMN
BECOMES FAIRLY SATURATED THIS AFTERNOON...WITH INTERMITTENT LIGHT TO
MODERATE RAIN EXPECTED THROUGH THE END OF THE FORECAST PERIOD. IFR
CONDITIONS ARE POSSIBLE THIS EVENING AND THROUGH THE OVERNIGHT
HOURS...HOWEVER MODELS ARE NOT IN AGREEMENT AT THIS TIME.

EXTENDED OUTLOOK...PREDOMINATELY VFR WITH MVFR/IFR CONDITIONS
FROM ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE
EXTENDED. BRIEF MVFR/IFR MORNING FOG/STRATUS IS ALSO EXPECTED EACH
DAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/... AS OF 1030 AM SUNDAY...NO CHANGES TO
THE FORECAST. THE PREVIOUS DISCUSSION STILL APPLICABLE:

AS OF 630 AM SUNDAY...SOUTHEAST GROUND SWELL AROUND 3 FT...UP TO
4 FT CURRENTLY ACROSS 41013...EXHIBITING 11 SECOND PERIODS...WILL
DOMINATE THE SIGNIFICANT SEAS THRUOUT THIS NEAR TERM PERIOD. THIS
IS THE SWELL CREATED BY ERIKA AS SEEN BY LOOPS OF WAVEWATCH3 MODEL
WAVE DATA.

THE SFC PRESSURE PATTERN AND GRADIENT FROM THE HIGH CENTERED
NORTH OF THE AREA WATERS...WILL RELINQUISH ITS HOLD ACROSS THE
LOCAL WATERS EARLY THIS PERIOD. THIS WILL ALLOW THE OLD FRONTAL
BOUNDARY...NOW JUST A SFC TROF OF LOW PRESSURE...TO PUSH BACK
TOWARD THE WEST INTO THE LOCAL WATERS TONIGHT. WIND DIRECTIONS
WILL RUN NE-E TODAY...E TO SE...TO POSSIBLY S DURING TONIGHT.
WITH A RELAXED SFC PG...WIND SPEEDS WILL RUN 10 KT OR LESS.

HAVE STAYED CLOSER TO THE DRIER GFS BIAS FOR LOWER PCPN CHANCES
AND COVERAGE...AND ALSO A SLOWER LOWERING OF CEILINGS DURING
THE DAYTIME AND EVENING SUN HOURS. THUS...WILL INDICATE VCNTY
SHRA AND HOLD OFF WITH THUNDER FOR THIS 06Z PACKAGE AT ALL SITES.
WINDS AT THE 06Z INITIAL TIME WILL EITHER START OUT WITH CALM
INLAND...TO NE 2 TO 4 KT AT THE COAST...BECOMING NE 4 TO 8 KT
DURING DAYTIME SUN MORNING AT ALL SITES. LOOK FOR FURTHER
VEERING TO E-SE AT 5 TO 10 KT DURING SUN AFTN AND EARLY
EVENING...DROPPING TO LESS THAN 5 KT BY MID TO LATE SUN EVENING.
THUS NEARLY NEGLIGIBLE WHEN COMPUTING THE SIGNIFICANT SEAS FOR
THIS PERIOD.

WILL HAVE TO MONITOR THIS SE GROUND SWELL FOR ANY FLUCTUATIONS
HIGHER THAT COULD RESULT IN THRESHOLDS BEING REACHED FOR A
SCEC...OR POSSIBLY EVEN A SCA.

WIDELY SCATTERED CONVECTION ACROSS THE AREA WATERS THIS
MORNING...IS PROGGED TO BECOME MORE WIDESPREAD THIS AFTERNOON AND
ESPECIALLY TONIGHT.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 325 AM SUNDAY...IT APPEARS THE STRONGEST WINDS WILL OCCUR EARLY
MONDAY AS GOOD MID LEVEL FORCING LEADS TO THE DEVELOPMENT OF A
COASTAL TROUGH. SHOULD SEE SOUTHEAST WINDS OF 10-15 KNOTS FOR A FEW
HOURS. THIS TROUGH MOVES INLAND WITH THE SEA BREEZE AND BASICALLY
DISSIPATES EARLY TUESDAY. IN ITS WAKE WEAK WINDS OF TEN KNOTS OR
LESS DEVELOP WITH THE DIRECTIONS MAINLY DICTATED BY THE LAND AND SEA
BREEZES. SEAS WILL SEE A BRIEF PERIOD OF 2-4 FEET MONDAY MORNING
AND TREND DOWNWARD SLIGHTLY THEREAFTER.

LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 325 AM SUNDAY...VERY LITTLE IN THE WAY SYNOPTICALLY TO SHOW ANY
DEVIATION FROM THE STANDARD SUMMERTIME PATTERN OF WEAK SOUTHEAST
WINDS AND SEAS OF 2-4 FEET. SOME CONVECTION COULD BRIEFLY DISTORT
THESE FIELDS OCCASIONALLY BUT THESE SHOULD HOLD FOR THE MOST PART.

&&

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

&&

$$
SYNOPSIS...SHK
NEAR TERM...MBB/DCH
SHORT TERM...SHK
LONG TERM...JDW/SHK
AVIATION...43


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