Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 200302
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1102 PM EDT SAT APR 19 2014

.SYNOPSIS...
WET WEATHER ASSOCIATED WITH AN OFFSHORE STORM SYSTEM WILL LAST
THROUGH TONIGHT AND INTO AT LEAST EARLY SUNDAY ALONG THE COAST.
AFTER A BRIEF PERIOD OF DRY WEATHER ON MONDAY...THE NEXT CHANCE
FOR RAIN WILL COME ON TUESDAY WITH A WEAK COLD FRONT. WARMING
TEMPERATURES ARE EXPECTED FOR THE LATTER PART OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1045 PM SATURDAY...VERTICALLY STACKED LOW PRESSURE OFF THE
NORTH FLORIDA COAST LATE THIS EVENING...WILL MEANDER TOWARD THE
EAST-NORTHEAST OVERNIGHT INTO SUNDAY...AND REMAIN OVER THE
OFFSHORE WATERS OFF THE SE U.S. COAST. WEAK VORTS/IMPULSES
ROTATING COUNTER-CLOCKWISE AROUND THE UPPER LOW OVERNIGHT INTO
SUNDAY...WILL OCCASIONALLY MOVE ONSHORE AND AFFECT THE CAROLINAS.
THE MODELS INDICATE THE BEST UVVS ASSOCIATED WITH THESE VORTS TO
OCCUR ACROSS SE NORTH CAROLINA THEN WEAKEN AS THEY MOVE FURTHER
INLAND. AS A RESULT...HAVE CONTINUED TO UPDATE OR RE-ALIGN
THE OVERNIGHT PERIOD INTO DAYLIGHT SUNDAY POPS TAKING INTO
CONSIDERATION THE CURRENT 88-D MOSAIC TRENDS AND APPLYING OR
MESHING IT WITH THE BEST UVVS ASSOCIATED WITH THE ONSHORE
MOVEMENT OF THESE VORTS. WITH THE COASTAL TROF REMAINING AND
DRIFTING FURTHER OFFSHORE...HAVE INDICATED MAINLY STRATIFORM PCPN
TYPE OVER LAND AREAS WITH SOME CONVECTIVELY ENHANCED RW+ FROM THE
DAMPENING CONVECTION MOVING ONSHORE WHICH DEVELOPED ALONG OR
JUST SOUTH AND EAST OF THE OFFSHORE COASTAL TROF. QPF HAS ALSO
BEEN RE-APPLIED WITH THE GENERAL CONSENSUS OF THE HIGHER AMOUNTS
ACROSS THE COASTAL COUNTIES. CURRENT MIN TEMP FORECAST CONTINUES
TO REMAIN IN LINE AND SEE NO REASON TO TEMPER WITH.

WIND GUSTS ALONG THE IMMEDIATE COAST WILL RANGE BETWEEN 30 AND 40
MPH LATER TONIGHT INTO SUNDAY. THIS REMAINS BELOW WIND ADVISORY
CRITERIA AND THUS WILL LIKELY HANDLE THEM WITH SPECIAL WEATHER
STATEMENTS IF NEED BE.

PREVIOUS DISCUSSION............................................
AS OF 3:00 PM SATURDAY...BEAUTIFUL SATELLITE IMAGERY THIS AFTN AS
AN AREA OF LOW PRESSURE SPINS SLOWLY OFF THE NORTH-FLORIDA
ATLANTIC COAST. A TROUGH/COASTAL FRONT EXTENDING NE FROM THIS LOW
PRESSURE TO UP ALONG THE NC COAST...IS STRENGTHENING THIS
AFTN...WHICH WILL HELP ONCE AGAIN INCREASE RAINFALL ACROSS THE
AREA. ADDITIONALLY...A RIDGE OF HIGH PRESSURE ITS TRYING TO PUSH
DOWN INTO THE SOUTHEAST...DRIVING A PINCHED PRESSURE GRADIENT
WHICH WILL SUPPORT STRONG NE WINDS TONIGHT.

WELL RAINFALL THIS AFTN HAS NOT BE AS IMPRESSIVE AS ANY OF THE HIGH
RES GUIDANCE HAS BEEN SUGGESTING...MAKING IT DIFFICULT TO TRUST ANY
OF IT FOR THE REMAINDER OF THE NEAR TERM. BELIEVE THE RAIN HAS NOT
BEEN AS SIGNIFICANT DUE TO DRIER AIR ALOFT SW OF THE LOCAL
AREA...FROM WHICH THE BEST "MOIST" LIFT IS ORIGINATING. DRY
ISENTROPIC LIFT WILL NEVER CREATE SHOWERS...AND THUS ONLY CLOUDS AND
DRIZZLE HAVE BEEN ABLE TO PERSIST TODAY...DEVELOPING FROM THE
SATURATED NEAR-SURFACE LAYERS. THE GFS FORECAST SOUNDINGS BEST MATCH
THE OBSERVED SOUNDINGS FROM KCHS AND KFFC THIS MORNING...AND THUS IS
USED PREFERENTIALLY. LATEST KLTX RADAR DOES SHOW SHOWER ACTIVITY
REDEVELOPING ALONG THE COASTAL TROUGH JUST OFFSHORE...AND EXPECT
THIS TO BECOME MORE WIDESPREAD THIS EVENING AND TONIGHT...AND ADVECT
BACK TOWARDS THE COAST...ESPECIALLY THE CAPE FEAR REGION. HAVE
DECREASED POP FROM EARLIER...BUT STILL SHOW LIKELY POP ALONG THE
IMMEDIATE COAST TONIGHT...WITH LOW-CHC INLAND. AS THE NOCTURNAL
INVERSION DEVELOPS AND MOISTURE DOES WRAP BACK INTO THE AREA AROUND
THE LOW MOVING UP THE COAST...DRIZZLE/MIST MAY BECOME WIDESPREAD
ONCE AGAIN...AND COULD BE THE PREDOMINANT PRECIP MODE INLAND. AT THE
SAME TIME...THE INTERACTION OF THE LOW MOVING UP THE COAST AND THE
HIGH RIDGING DOWN FROM THE NORTH WILL DRIVE A TIGHTENING GRADIENT.
LLJ IS PROGGED TO RISE TO 40 KTS TONIGHT AT ONLY 1500 FT AGL...THUS
WIND GUSTS OF 25 TO 35 MPH WILL BECOME COMMON ACROSS THE
AREA...HIGHEST AT THE COAST.

TONIGHT...TEMPS WILL STRUGGLE TO FALL EVEN ON THE COOL NE FLOW. LOW
CLOUDS AND SHOWERS WILL KEEP DIURNAL RANGES LIMITED TO ONLY AROUND
10 DEGREES. THUS...EXPECT LOWS TONIGHT JUST ABOVE 50 AT THE
COAST...AND JUST BELOW 50 TOWARDS I-95.

&&

.SHORT TERM /6 AM SUNDAY THROUGH 6 AM SUNDAY/...
AS OF 3:00 PM SATURDAY...GUIDANCE CONSISTENT IN DRIFTING A
VERTICALLY STACKED SYSTEM CURRENTLY MOVING OFFSHORE NORTHERN
FLORIDA TO THE NORTHEAST AND EVENTUALLY AWAY FROM THE EASTERN
CAROLINAS DURING THE SHORT TERM. MOISTURE PULLS AWAY WITH THE
SYSTEM...ALLOWING PRECIPITATION CHANCES TO GRADUALLY FADE FROM NW
TO SE DURING THE DAY ON SUNDAY. HIGHEST PRECIPITATION CHANCES WILL
BE SUNDAY MORNING AND ALONG THE COAST WHEN AND WHERE WE CAN EXPECT
LINGERING LIGHT RAIN OR DRIZZLE TO HANG ON BEFORE FADING DURING
THE AFTERNOON HOURS. OVERNIGHT SUNDAY AND MONDAY WILL BE DRY AS
RIDGING AT THE SURFACE AND ALOFT TRANSITS THE REGION FROM WEST TO
EAST.

GRADIENT ALONG BACKSIDE OF OFFSHORE SYSTEM WILL MAKE FOR A BREEZY
COUPLE OF DAYS...ESPECIALLY ON SUNDAY...WHEN WE WILL SEE NORTH TO
NORTHEASTERLY WINDS IN THE 15 TO 20 KT RANGE...IN ADDITION TO THE
HIGHER GUSTS.

COOL NORTHEASTERLY FLOW AND EXTENSIVE CLOUD COVER WILL KEEP SUNDAY
DAYTIME TEMPERATURES WELL BELOW NORMAL WITH HIGHS ONLY IN THE MID
60S. MONDAY WILL BE WARMER AS MORE SUNSHINE CAN BE EXPECTED...WITH
HIGHS OF RIGHT AROUND 70.

&&

.LONG TERM /SUNDAY THROUGH SATURDAY/...
AS OF 3:00 PM SATURDAY...A SURFACE RIDGE AXIS OVER THE EASTERN
CAROLINAS ON TUESDAY WILL FADE AND SHIFT OFF THE COAST AHEAD OF A
COLD FRONT. MODELS HAVE BEEN CONSISTENT IN TIMING FROPA FOR TUESDAY
NIGHT. PREDOMINANTLY WESTERLY FLOW THROUGHOUT THE COLUMN IN ADVANCE
OF THE FRONT WILL SIGNIFICANTLY LIMIT MOISTURE AND THE COVERAGE OF
ANY ASSOCIATED CONVECTION IS EXPECTED TO REMAIN SCATTERED. SURFACE
HIGH PRESSURE WILL SHIFT OFFSHORE BY THE END OF THE WEEK AND A 500
MB RIDGE AXIS WILL TRAVERSE THE AREA FRIDAY. ALTHOUGH TEMPS
WON`T COOL DOWN MUCH BEHIND THE FRONT...THERE WILL BE A MODEST
UPWARD TREND IN TEMPS THU-SAT. WILL INTRODUCE A SMALL POP FRI-SAT
DUE TO MOISTURE RETURN AHEAD OF A WEAK SURFACE TROUGH APPROACHING
FROM THE WEST.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
AS OF 00Z...EXPECT MVFR/IFR CONDITIONS TO PERSIST OVERNIGHT AND WELL
INTO THE MORNING HOURS AS A COASTAL SURFACE LOW CONTINUES TO MOVE
EAST-NORTHEAST OFFSHORE. CONDITIONS WILL GRADUALLY IMPROVE TO
WIDESPREAD MVFR ON SUNDAY...WITH IMPROVEMENT TO VFR POSSIBLE BEFORE
THE END OF THE VALID TAF PERIOD.

LATEST RADAR IMAGERY ILLUSTRATES RAINFALL PUSHING INLAND MAINLY
AFFECTING KILM...THOUGH KCRE/KMYR HAVE ALSO REPORTED -DZ/-RA...ALONG
WITH VCSH INLAND. LOW CIGS AND PATCHY AREAS OF FOG ARE CREATING
MVFR/IFR CONDITIONS. EXPECT THESE CONDITIONS ALONG WITH VCSH/-RA TO
CONTINUE INTO THE MORNING HOURS. COULD NOT ENTIRELY RULE OUT BRIEF
PERIODS OF IMPROVEMENT TO VFR...BUT GIVEN LOWERED CONFIDENCE ON
TIMING HAVE NOT INTRODUCED IN GOING FORECAST. SUNDAY...EXPECT
IMPROVEMENT TO WIDESPREAD MVFR WITH PRECIPITATION TAPERING OFF BY
THE EARLY AFTERNOON HOURS. COULD SEE IMPROVEMENT TO VFR TOWARDS THE
END OF THE PERIOD...BUT AGAIN GIVEN LOWERED CONFIDENCE HAVE NOT
INTRODUCED ATTM.

EXTENDED OUTLOOK...VFR ON MONDAY. CHANCE OF SHOWERS/TEMPO MVFR ON
TUESDAY WITH A COLD FRONT. VFR WEDNESDAY AND THURSDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 PM SATURDAY...GALE WARNING REMAINS IN EFFECT TONIGHT
THROUGH LATE SUNDAY AFTERNOON.

THE NE-SW ORIENTED COASTAL TROF NOW LOCATED OVER THE OFFSHORE
WATERS OF THE CAROLINAS...WILL DRIFT FURTHER OFFSHORE OVERNIGHT.
WITH THE VERTICALLY STACKED LOW PRESSURE SYSTEM MOVING ENE AND
FURTHER OFFSHORE...IT WILL BE AT ITS CLOSEST APPROACH TO THE ILM
COASTAL WATERS OVERNIGHT THRU SUNDAY. THE SFC PRESSURE PATTERN
AND A TIGHTENING SFC PG OVERNIGHT INTO SUNDAY...WILL YIELD NE
WINDS AT 20 TO 30 KT SUSTAINED WITH OCCASIONAL GUSTS OVER 35
KT...ALONG WITH POSSIBLE GUSTS PEAKING AROUND 40+ KT FROM ANY
DAMPENING CONVECTION THAT MOVES ACROSS THE LOCAL WATERS. KLTX
INDICATES 30 TO 40 KT WINDS JUST OFF THE DECK AND UP THRU 3K FT.
THE LOW TOPPED AND DAMPENING CONVECTION MOVING ACROSS THE WATERS
MAY ACCESS THESE HIGHER WINDS AND BRING THEM DOWN TO THE OCEAN SFC
AS GUSTS.

SIGNIFICANT SEAS HAVE BEEN ADJUSTED SLIGHTLY HIGHER ACROSS THE
AREA WATERS...THIS BASED ON LOCAL BUOY REPORTS AND TRENDS...IE.
41013 HAVING ALREADY TOPPED 11+ FEET THIS EVENING. IN GENERAL
...BUILDING SIG. SEAS UP TO 6 TO 10 FT OVERNIGHT AND CONTINUING
AT THESE LEVELS INTO SUNDAY. NO SWELL TO SPEAK OF...JUST MAINLY
WIND INDUCED WAVES GOVERNING THE SIG. SEAS WITH DOMINANT PERIODS
RUNNING 7 TO 8 SECONDS.

PREVIOUS DISCUSSION.............................................
AS OF 3:00 PM SATURDAY...GALE WARNING REMAINS IN EFFECT THROUGH
THE PERIOD. SLOW MOVING LOW PRESSURE NOW CENTERED JUST OFF THE
N-FL ATLANTIC COAST WILL GRADUALLY LIFT NE TONIGHT. AT THE SAME
TIME...A COASTAL TROUGH EXTENDING NE FROM THE PARENT LOW IS
STRENGTHENING OFF THE NC COAST...AND HAS DRIFTED SLIGHTLY EAST
SUCH THAT ALL COASTAL WATERS ARE NOW EXPERIENCING STRONG NE
WINDS...EVEN OUT TO FRYING PAN SHOALS. AS THIS LOW PRESSURE MOVES
CLOSER TONIGHT...AND HIGH PRESSURE TO THE NORTH CONTINUES TO RIDGE
INTO THE VICINITY...THE PRESSURE GRADIENT WILL ONLY STRENGTHEN.
THEREFORE...WINDS ARE EXPECTED TO RISE SIGNIFICANTLY
TONIGHT...BECOMING NE AT 20-30 KTS WITH GUSTS APPROACHING 40 KTS
TOWARDS SUNDAY MORNING. SEAS WILL RISE QUICKLY AS WELL...BECOMING
7-11 FT WITH A SHORT PERIOD NE WIND WAVE PREDOMINANT...FORCING
STEEP WAVE FACES. THE EXCEPTION WILL BE WITHIN THE WAVE SHADOWED
REGION SW OF BRUNSWICK COUNTY...WHERE WAVE HEIGHTS WILL REMAIN 2-4
FT.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 PM SATURDAY...PERIOD BEGINS WITH GALE WARNING FLAGS
FLYING AS THE TIGHT GRADIENT AROUND THE BACKSIDE OF AN OFFSHORE
SYSTEM WILL CRATE STRONG NORTHEASTERLY WINDS THROUGH AT LEAST THE
DAYLIGHT HOURS. SEAS MAY REACH AS HIGH AS 9 FT OVER THE OUTER
FRINGES OF OUR WATERS ON SUNDAY. CONDITIONS WILL GRADUALLY IMPROVE
SUNDAY NIGHT AND MONDAY AS THE OFFSHORE SYSTEM PULLS NORTHEAST AND
AWAY FROM THE COAST.

LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3:00 PM SATURDAY...WINDS WILL BECOME SW ON TUESDAY AHEAD OF A
COLD FRONT EXPECTED TO MOVE ACROSS THE WATERS LATE TUESDAY NIGHT.
NORTHERLY WINDS BEHIND THE FRONT WILL SURGE TO PERHAPS LOW-END SMALL
CRAFT ADVISORY LEVELS BEFORE THE GRADIENT WEAKENS BY MIDDAY.
DIRECTION WILL VEER TO THE SOUTHEAST BY THURSDAY AS THE CENTER OF
HIGH PRESSURE SLIDES OFFSHORE.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HIGH RIP CURRENT RISK FROM 8 AM EDT SUNDAY THROUGH SUNDAY
     EVENING FOR SCZ056.

NC...HIGH RIP CURRENT RISK FROM 8 AM EDT SUNDAY THROUGH SUNDAY
     EVENING FOR NCZ106-108.

MARINE...GALE WARNING UNTIL 6 PM EDT SUNDAY FOR AMZ250-252-254-256.

&&

$$
SYNOPSIS...REK
NEAR TERM...DCH/JDW
SHORT TERM...REK
LONG TERM...CRM
AVIATION...SGL




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