Area Forecast Discussion
Issued by NWS Wilmington, NC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KILM 052003
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
403 PM EDT THU MAY 5 2016

.SYNOPSIS...
COLD LOW PRESSURE ALOFT WILL DROP SOUTH OVER THE CAROLINAS
THROUGH THROUGH FRIDAY...MAINTAINING THE RISK FOR SMALL HAIL AND
GUSTY WINDS IN SHOWERS AND THUNDERSTORMS. DRY WEATHER AND WARMING
TEMPERATURES WILL FOLLOW FOR THE WEEKEND AND INTO EARLY NEXT
WEEK...WITH THE POTENTIAL FOR SCATTERED SHOWERS AND THUNDERSTORMS
RETURNING ON WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM THURSDAY...TROUGH CONTINUES TO EXTEND FROM LOW
PRESSURE JUST OFF THE TIP OF CAPE FEAR THIS MORNING TO A SECONDARY
WEAK LOW ASSOCIATED WITH POTENT UPPER LOW FARTHER INLAND. STORMS
WERE FIRING ALONG THIS TROUGH WITH SOME IMPRESSIVE CORES PRODUCING
MAINLY SMALLER SIZE BUT LARGE QUANTITY OF HAIL. LATEST MSAS
DEWPOINT AND PRESSURE ANALYSIS SHOW THIS TROUGH NICELY WITH MUCH
LOWER DEWPOINTS SOUTH AND WEST. MAINLY MORE ISOLATED GUSTY SHOWERS
TO THE SOUTH AND WEST IN DRIER AIR RATHER THAN WIDESPREAD HAIL.
MODEL SOUNDINGS INDICATE GREATER INSTABILITY AND BETTER LIFT ALONG
AND JUST TO NORTH AND EAST OF THIS TOUGH ALIGNED ALMOST TO THE TIP
OF CAPE FEAR UP NORTH AND WEST TO TO MT OLIVE AND EXTENDING N-NW
FROM THERE.

THE PRIMARY SFC LOW WILL SLOWLY STRENGTHEN AS IT LIFTS N OF THE
AREA INTO THIS AFTERNOON WHILE UPPER LOW DROPS SOUTH THIS SHOULD
ALLOW DRIER LOWER DEWPOINT AIR INLAND AND TO THE SW TO WORK ITS
WAY TO THE NC COAST. DEWPOINT TEMPS OVER NORTHEAST SC WERE IN THE
40S MOST PLACES ALL THE WAY TO THE COAST. ALTHOUGH THE RICHER
DEWPOINT AIR WILL MOVE OFF THE EAST THROUGH TODAY...THE POTENT MID
TO UPPER LOW WILL CONTINUE TO DROP SOUTH. THIS EXTREME COLD POOL
ALOFT...DROPPING TO -25 C...WILL STEEPEN LAPSE RATES THROUGH THE
DAY AS HEATING OCCURS AT THE SFC...ALLOWING CLOUDS AND SHOWERS TO
DEVELOP. THE STEEPEST LAPSE RATES WILL BE THIS AFTERNOON AND WITH
SUCH COOL AIR ALOFT AND WBZ HEIGHTS RUNNING AROUND 6500 FT...WILL
NOT TAKE MUCH TO PRODUCE SOME SMALL HAIL. ALSO THE INVERTED V TYPE
SOUNDING WITH VERY DRY AIR ALOFT...ABOVE 7K FT...WILL ALSO ALLOW
FOR SOME STRONG GUSTY WINDS IN SHOWERS THAT DEVELOP. THE LOWEST
HEIGHTS AND COLDEST AIR ALOFT SHOULD BE OVER THE ILM AREA JUST
AFTER MIDNIGHT TONIGHT. OVERALL EXPECT ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS TO CONTINUE WITH THE GREATEST COVERAGE
INTO THIS EVE AND STRONGEST STORMS ALIGNED WITH TROUGH EXTENDING
NORTH TO NORTHWEST OF CAPE FEAR.. THE SMALL HAIL OR GUSTY WINDS
ARE NOT EXPECTED TO REACH SEVERE CRITERIA. EXPECT SHWRS/TSMS TO
DIMINISH IN INTENSITY AND COVERAGE...KEEPING MAINLY ISO IN SC AND
SCT IN NC.

HIGHS TODAY WILL BE BELOW SEASONABLE NORMALS...UPPER 60S TO
LOWER 70S AS CAA CONTINUES THROUGH THE DAY. 850 TEMPS WILL BOTTOM
OUT THROUGH EARLY FRI MORNING DOWN AROUND 4C. THE LOWER DEWPOINT
AIR WILL ALLOW ALREADY COOL TEMPS TO DROP OFF TONIGHT BUT WINDS
WILL NOT DROP OFF COMPLETELY AND THEREFORE EXPECT LOWS TONIGHT IN
THE UPPER 40S TO AROUND 50. MOST PLACES WILL DROP INTO THE 40S.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 PM THURSDAY...POTENT UPPER LOW OVER CAPE HATTERAS EARLY
FRIDAY WILL BE LIFTING SLOWLY OFF TO THE NORTH. THE LOWEST HEIGHTS
AND COLDEST AIR ALOFT WILL BE PAST BUT AS THE LOW LIFTS OFF TO THE
NORTH SHORTWAVE ENERGY WILL CONTINUE TO ROTATE AROUND IT AND LAPSE
RATES WILL STILL REMAIN STEEP. DO NOT EXPECT SAME ATMOSPHERE AS
THURSDAY AS SFC LOW WILL BE LIFTING OFF TO THE NORTH AND BEST LIFT
SHOULD BE LIFTING OFF WITH IT...BUT WILL MAINTAIN SHOWERS AND
POSSIBLE THUNDERSTORMS AS THE POTENT LOW REMAINS CLOSE. THE
GREATEST CHANCE SHOULD COINCIDE WITH MAX HEATING IN THE AFTERNOON
INTO EARLY EVE WHEN LAPSE RATES WILL BE STEEPEST.

THIS UPPER LOW WILL LIFT FURTHER OFF TO THE NORTH ON SATURDAY AS
RIDGE BEGINS TO BUILD IN FROM THE WEST. EXPECT WARMING AND DRYING
THROUGH THE DAY WITH INCREASED SUBSIDENCE AND HEIGHT RISES. TEMPS
WILL REACH THE UPPER 60S TO AROUND 70 ON FRI BUT WILL WARM TO THE
MID OR UPPER 70S BY SAT. LOWS IN THE LOWER TO MID 50S FRI NIGHT
WILL BE NEAR 60 SAT NIGHT.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 300 PM THURSDAY...SUMMER-LIKE PATTERN NEXT WEEK AS BERMUDA
HIGH PRESSURE AND STRONG SE RIDGING DEVELOPS. UPPER LOW PLAGUING THE
AREA THIS WEEK WILL GET KICKED OFF TO THE EAST BY A SHORTWAVE
DROPPING INTO NEW ENGLAND ON SUNDAY. THIS SHORTWAVE WILL DRIVE A
WEAK COLD FRONT TOWARDS THE CAROLINAS LATE SUNDAY...AND WHILE
GUIDANCE DISAGREES ON ITS SOUTHERN PROGRESSION...BLOSSOMING OF UPPER
RIDGE FROM THE GULF COAST WILL SIGNIFICANTLY IMPEDED ITS PROGRESS.
GFS IS NOW THE MOST AGGRESSIVE SOLUTION (OPPOSITE OF YESTERDAY)
WHILE THE ECM/CMC SHOW SIMILAR EVOLUTIONS WITH THE FRONT DISSIPATING
ALONG THE NORTHERN EDGE OF THE CWA. THIS SEEMS THE MORE REASONABLE
SOLUTION AND WILL SHOW A SUBTLE WIND SHIFT IN THE NORTH AND KEEP ANY
POP CONFINED OUT OF THE CWA.

THEREAFTER...HEAT RETURNS TO THE AREA AS 850MB TEMPS CLIMB TO AROUND
15C AS THICKNESSES RISE AND WARM ADVECTION INCREASES THROUGH THE
MIDDLE OF NEXT WEEK. TEMPS SUNDAY WILL BE ABOVE CLIMO...BUT MON-THU
WILL FEATURE WIDESPREAD MID TO UPPER 80S...COOLER AT THE COAST. AS
THIS HEAT INCREASES...HUMIDITY WILL FOLLOW...AND SCATTERED DIURNAL
CONVECTION WILL BECOME INCREASINGLY LIKELY...ESPECIALLY LATE IN THE
PERIOD. FORTUNATELY...SIGNIFICANT FORCING IS NOT EVIDENT ON THE LONG
TERM SO NATURE IS EXPECTED TO BE SCATTERED AND WILL MAINTAIN BARELY
MENTIONABLE POP.

&&

.AVIATION /18Z THURSDAY THROUGH MONDAY/...
AS OF 18Z...LOW PRESSURE VERY NEAR WILMINGTON HAS A LARGE
COUNTERCLOCKWISE SWIRL OF WIND AND THUNDERSTORMS SURROUNDING IT.
AS THIS LOW NUDGES OFFSHORE OVER THE NEXT COUPLE OF HOURS EXPECT
VARIABLE WIND DIRECTIONS AT ILM TO BECOME NW AND GUSTY. VERY COLD
AIR TEMPERATURES ALOFT PLUS STRONG MAY SUNSHINE WILL YIELD
SCATTERED SHOWERS TODAY...POTENTIALLY CONTINUING INTO TONIGHT AS
THE CORE OF THE COLD AIR ALOFT MOVES OVERHEAD. CEILINGS SHOULD
REMAIN VFR EXCEPT IN AND NEAR SHOWERS WHERE 2500-3000 FOOT
CEILINGS MAY BRIEFLY OCCUR.

EXTENDED OUTLOOK...VFR CONDITIONS EXPECTED WITH THE EXCEPTION OF
MVFR CONDITIONS IN SCATTERED SHOWERS FRIDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM THURSDAY...SMALL CRAFT SHOULD EXERCISE CAUTION
HEADLINES WILL CONTINUE THROUGH THIS EVENING FOR GUSTY WINDS UP TO
20 TO 25 KTS AND SEAS UP TO 3 TO 5 FT. STEEPENING LAPSE RATES WILL
RESULT IN A WELL MIXED ENVIRONMENT ACROSS THE WATERS AS POTENT
UPPER LOW DROPS SOUTH AND DEPOSITS VERY COLD AIR ALOFT OVER THE
AREA WATERS THROUGH TONIGHT. THIS WILL RESULT IN STRONGER WINDS
ALOFT MIXING TO THE SEA SURFACE. ALSO...LOW PRESSURE NEAR THE CAPE
FEAR COAST WILL LIFT N INTO THIS AFTERNOON AND STRENGTHEN...TIGHTENING
THE PRESSURE GRADIENT. WINDS WILL BE MORE WESTERLY IN THE WATERS
SOUTH OF CAPE FEAR AND WILL VEER AROUND FORM THE N-NE TO THE NW TO
W NORTH OF CAPE FEAR. STRONGER OFF SHORE FLOW WILL KEEP SEAS CLOSE
TO THE COAST LOWER AND HIGHEST SEAS WELL OFF SHORE.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 PM THURSDAY...WESTERLY WINDS WILL CONTINUE THROUGH THE
PERIOD WITH A BRIEF SHIFT TO THE NW FRI NIGHT AND SHIFT TO MORE
W-SW SAT NIGHT...REMAINING MAINLY 15 TO 20 KT MOST OF THE TIME.
THE PERSISTENT OFFSHORE WIND DIRECTION WILL KEEP SEAS GREATESTSEAS
OFFSHORE WITH 2 TO 3 FT EXPECTED NEAR SHORE AND UP TO 4 FT OUTER
WATERS.

LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 300 PM THURSDAY...HIGH PRESSURE OFFSHORE WILL BE THE DOMINANT
FEATURE THIS PERIOD...AND ITS STRENGTH WILL CAUSE A COLD FRONT
SUNDAY EVENING TO STALL NORTH OF THE AREA. THIS WILL CAUSE WINDS TO
BE SOUTH TO SW THROUGH THE PERIOD...WITH SPEEDS OF 10-15 KTS
EXPECTED MUCH OF THE TIME. THE EXCEPTION WILL BE EARLY SUNDAY WHEN
SPEEDS OF 15-20 KTS ARE POSSIBLE. THESE PERSISTENT WINDS COMBINED
WITH LONG FETCH AROUND THE OFFSHORE HIGH PRESSURE WILL CREATE A WAVE
SPECTRUM FORMED THROUGH A SOUTHERLY 4-5 SEC WAVE AND A SE 8-9 SEC
WAVE...WITH SEAS OF 2-4 FT FORECAST THROUGHOUT.

&&

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

&&

$$

NEAR TERM...RGZ
SHORT TERM...RJD
LONG TERM...SGL
AVIATION...DL


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.