Area Forecast Discussion
Issued by NWS Wilmington, NC

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FXUS62 KILM 031857
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
257 PM EDT FRI JUL 3 2015

.SYNOPSIS...
BERMUDA HIGH PRESSURE WILL PERSIST THROUGH UPCOMING HOLIDAY
WEEKEND. THIS WILL CREATE SLIGHTLY ABOVE NORMAL TEMPERATURES...ALONG
WITH TYPICAL SUMMERTIME THUNDERSTORM CHANCES EACH AFTERNOON AND
EVENING. A FRONT MAY STALL TO OUR NORTH OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 3 PM FRIDAY...THE ENTIRE FORECAST AREA IS NOW IN A SLIGHT
CHANCE RISK FOR SEVERE THUNDERSTORMS WITH THE GREATEST THREAT BEING
FROM WIND DAMAGE...WHICH SPC RATES AT 15 PERCENT. TRENDS SHOW THAT
THE STRONGEST CONVECTION NOW UNDERWAY IS ACTUALLY PASSING TO OUR
SOUTH AS A SHORT WAVE ROTATES OFFSHORE. TEMPERATURES HAVE BEEN
SUPPRESSED OVER THE EASTERN CAROLINAS DUE TO EXTENSIVE CLOUD COVER
AND THIS HAS KEPT A DAMPER ON STRONG CONVECTION OVER OUR FORECAST
AREA. BREAKS IN THE CLOUD COVER ARE DEVELOPING AND THAT MAY HELP POP
SOME STRONGER SHOWERS AND THUNDERSTORMS LATER ON...BUT SO FAR
CONVECTION HAS BEEN GENERALLY WEAK WITH LITTLE LIGHTNING AND NO
STRONG WINDS. A SEVERE WATCH AREA REMAINS TO OUR S AND SW AND IF
CURRENT TRENDS CONTINUE DO NOT EXPECT IT WILL BE EXTENDED UP OUR
WAY...ALTHOUGH STRONG CONVECTION PASSING JUST TO OUR SOUTH MAY BRUSH
GEORGETOWN COUNTY BEFORE MOVING OFFSHORE THIS AFTERNOON.

A BROADLY CYCLONIC YET RELATIVELY FLAT PATTERN WILL PERSIST ALOFT
THROUGH THE NEAR TERM...AS WILL THE BERMUDA HIGH/INLAND THERMAL
TROUGH PATTERN AT THE SURFACE. TO OUR NORTH A FRONT WILL REMAIN
STALLED ALONG THE NC/VA BORDER. COMBINE THESE FACTORS WITH A VERY
MOIST AND MODERATELY UNSTABLE AIRMASS AND WE WILL CONTINUE TO SEE
THE GOOD CHANCE FOR CONVECTION THIS AFTERNOON AND EVENING. THE USUAL
SUSPECTS WILL BE IN PLAY AS FAR AS CONVECTION GOES...DIURNAL
HEATING...THE SEA BREEZE FRONT...THE INLAND THERMAL TROUGH...OLD
OUTFLOW BOUNDARIES AND UPPER LEVEL DISTURBANCES. THIS LATTER FACTOR
WILL BRING THE GREATEST POTENTIAL FOR STRONG CONVECTION AS A SERIES
OF SHORT WAVES CYCLE THROUGH THE BASE OF THE UPPER TROUGH. EXACT
TIMING OF THESE UPPER FEATURES IS...AS ALWAYS...AN IFFY
PROPOSITION...BUT A COMBINATION OF  GUIDANCE...AND WATER VAPOR AND
RADAR LOOPS SHOWS ONE SUCH SHORT WAVE MOVING THROUGH THIS
AFTERNOON...FOLLOWED BY ANOTHER THIS EVENING AND POSSIBLY A THIRD
ONE OVERNIGHT.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...HOT BUT MOSTLY DRY FOR THE 4TH OF
JULY...COOLER AND MORE UNSETTLED WEATHER WILL FOLLOW FOR THE 2ND
HALF OF THE WKND.

EASTERN CONUS TROUGH WILL PERSIST THIS WKND...BUT AS THE TROUGH AXIS
REMAINS WEST OF THE LOCAL AREA...SUBTLE SHORTWAVE RIDGING WILL EXIST
OVER THE CWA SATURDAY. THIS WILL COMBINE WITH SUBSIDENCE BEHIND A
DEPARTING SHORTWAVE FROM OVERNIGHT FRIDAY NIGHT...TO PRODUCE A HOT
AND MOSTLY SUNNY AND DRY DAY. TEMPS WILL WARM INTO THE LOW-TO-MID
90S AWAY FROM THE BEACHES...WITH UPR 80S EXPECTED ALONG THE COAST.
VERY DRY-MID LEVELS WILL PRECLUDE MUCH IN THE WAY OF CONVECTION EVEN
AS AFTN CU BUILDS...SO BUILDUP WILL LIKELY REMAIN PRETTY SHALLOW.
THE SEA BREEZE...AND ESPECIALLY PIEDMONT TROUGH...MAY BE ABLE TO
OVERCOME THIS DRY AIR ENOUGH TO PRODUCE A FEW SHOWERS/TSTMS SATURDAY
EVENING...BUT FOR THE MOST PART FIREWORKS FESTIVITIES SATURDAY NIGHT
SHOULD BE CLEAR AND DRY WITH LOWS SATURDAY NIGHT DROPPING INTO THE
LOW 70S WELL INLAND...MID 70S AT THE COAST.

A MORE TYPICAL SUMMERTIME DAY ON TAP FOR SUNDAY WITH MORE SCATTERED
DIURNAL CONVECTION. SHORTWAVE WILL TRY TO CLOSE OFF ACROSS THE TN
VLY...AND WHILE THIS WILL STAY MOSTLY WEST OF OUR AREA...SUBTLE
HEIGHT FALLS ARE EXPECTED ALONG WITH INCREASING MOISTURE AND BETTER
PVA. THIS WILL CREATE MORE CLOUD COVER AND BETTER AFTN CONVECTION
CHANCES...ALONG WITH KEEPING TEMPS A FEW DEGREES COOLER...WITH MOST
PLACES HOVERING 1-2 DEGREES EITHER SIDE OF 90. CONTINUING HEIGHT
FALLS AND SHORTWAVE ENERGY MAY PERSIST CONVECTION WELL INTO SUNDAY
NIGHT...ALTHOUGH WITH DECREASED COVERAGE...AND MINS SUNDAY NIGHT
WILL FALL TO SEASONABLE LEVELS AROUND 70...SEVERAL DEGREES
WARMER AT THE COAST.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...MONDAY AND TUESDAY STILL HAVE SOME
INGREDIENTS IN PLACE THAT COULD KEEP THE WEATHER SOMEWHAT
UNSETTLED ESPECIALLY BY JULY STANDARDS. MID LEVEL TROUGH REMAINS
JUST TO OUR WEST ALBEIT IN A WEAKENING STATE WHILE AT THE SURFACE
A PIEDMONT TROUGH WORKS IN TANDEM WITH SEA BREEZE AND OUTFLOW
BOUNDARIES TO INITIATE CONVECTION. DEEP SWRLY FLOW COULD BRING
MORE CLOUDS THAN WE TYPICALLY SEE THIS TIME OF YEAR. THE NET
EFFECT OF THE CLOUDINESS WILL BE TO TEMPER DAYTIME HIGHS SLIGHTLY
WHILE BOLSTERING NIGHTTIME LOWS. THE MID LEVEL FEATURE WEAKENS FOR
THE REMAINDER OF THE PERIOD AND WE SHOULD TRANSITION BACK TO A
REGIME WHERE MID LEVEL FLOW IS VERY WEAK AND SURFACE MESOSCALE
FEATURES ACT AS THE LONE CONVECTIVE INITIATORS. TEMPERATURES
SHOULD BE CLOSE TO SEASONABLE.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AS OF 12Z...IFR/LIFR CIGS ARE AFFECTING THE KFLO/KLBT TERMINALS.
WITH WEST WINDS JUST OFF THE SURFACE THERE IS A CHANCE AT LEAST
MVFR CIGS COULD AFFECT THE COASTAL TERMINALS THIS MORNING.
ISOLATED SHOWERS HAVE ALSO DEVELOPED BUT NO THUNDERSTORMS AS OF
YET. CIGS SHOULD DECREASE AND LIFT TO VFR MID-LATE MORNING. SW
WINDS EXPECTED EXCEPT BECOMING S-SW AT THE COASTAL TERMINALS IN
THE AFTERNOON.

MODELS SUGGESTING AN OVERALL WET DAY TODAY. THIS SEEMS LIKELY
BASED ON CURRENT RADAR TRENDS WHERE EVEN WITHOUT HEATING SHOWERS
ARE DEVELOPING AND INCREASING IN COVERAGE. WILL INDICATE VCSH IN
TAFS INTO THE EVENING WITH SHRA/VCTS/MVFR AT KFLO/KLBT AROUND 17Z
AND AT THE COASTAL TERMINALS IN THE AFTERNOON. CONFIDENCE IS LOW
AS TO TIMING. CONVECTIVE ACTIVITY WILL LIKELY ALTER THE SURFACE
WIND FIELD GREATLY BUT EXPECT WINDS TO RECOVER AFTER SEVERAL HOURS
TO AT PREDOMINATE SW DIRECTION. TSRA SHOULD DECREASE THIS EVENING
BUT CANT DISCOUNT AN ISOLATED SHOWER OVERNIGHT. WINDS WILL BE
LIGHT SW AND COULD BE IFR STRATUS IN THE AM AGAIN BUT CONFIDENCE
IS LOW.

EXTENDED OUTLOOK...CHANCE OF SHOWERS AND THUNDERSTORMS EACH
DAY...WITH BRIEF PERIODS OF MVFR/IFR POSSIBLE. OTHERWISE EXPECT
VFR.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM FRIDAY...BERMUDA HIGH/INLAND TROUGH PATTERN WILL PERSIST
THROUGH THE NEAR TERM...WITH SW WINDS INCREASING FROM THE PRESENT 10
TO 15 KTS TO THE 15 TO 20 KT RANGE FOR AMZ252-256 THIS AFTERNOON AND
PERSISTING TONIGHT. SEAS WILL BUILD TO 3 TO 5 FT FOR THOSE WATERS.
THE EXCEPTION WILL BE FOR AMZ250...WHERE WINDS WILL INCREASE TO 20
TO 25 KTS AND SEAS WILL BUILD TO 4 TO 6 FT. A SMALL CRAFT ADVISORY
IS IN EFFECT TONIGHT FOR THAT ZONE...WITH EXERCISE CAUTION HEADLINES
OUT FOR THE REMAINDER.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...BERMUDA HIGH PRESSURE REMAINS THE DOMINANT
FEATURE DURING THE SHORT TERM...WITH SW WINDS EXPECTED THROUGH THE
WEEKEND. ALTHOUGH DIRECTION WILL VARY LITTLE...SPEEDS SATURDAY WILL
INCREASE TO 15-20 KTS...HIGHEST LATE AFTN/EVE AS THE GRADIENT
TIGHTENS THANKS TO THE SHARPENING PIEDMONT TROUGH. WINDS WILL BE 10-
15 KTS SUNDAY AS THE GRADIENT REMAINS A BIT WEAKER.
ADDITIONALLY...NEAR SHORE WINDS WILL BACK MORE TO THE SOUTH WITH THE
SEA BREEZE SATURDAY AFTN AND EVE BEFORE RETURNING TO A SW DIRECTION
SATURDAY NIGHT. WAVE HEIGHTS WILL REMAIN 3-4 FT BOTH DAYS...WITH A
SW WIND WAVE PREDOMINANT IN THE SPECTRUM

LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 AM FRIDAY...INLAND SURFACE TROUGHINESS APPEARS RATHER
WEAK MONDAY AND TUESDAY LIKELY WASHED OUT IN PART BY THE FLOW
ASSOCIATED WITH THE FRONT THAT HAD BEEN STALLED TO OUR NORTH
DURING THE SHORT TERM PERIOD. SEAS WILL RELAX SOMEWHAT NOT ONLY
DUE TO THE DOWN TICK IN WIND SPEED BUT ALSO THE DECREASED AREAL
COVERAGE OF THE FETCH ALONG THE EAST COAST.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EDT
     SATURDAY FOR AMZ250.

&&

$$
SYNOPSIS...SHK/JDW
NEAR TERM...REK
SHORT TERM...JDW
LONG TERM...99
AVIATION...MRR
MARINE...99/REK/JDW


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