Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 100750
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
350 AM EDT THU JUL 10 2014

.SYNOPSIS...
A COLD FRONT WILL STALL ACROSS THE REGION TONIGHT...PERSISTING
INTO EARLY SATURDAY. THIS WILL BRING GOOD CHANCES FOR
THUNDERSTORMS THE NEXT FEW DAYS...WITH PERIODS OF HEAVY RAINFALL.
THIS FRONT WILL DISSIPATE LATE IN THE WEEKEND WITH A RETURN TO
TYPICAL SUMMERTIME CONDITIONS...WITH A WARMING TREND DEVELOPING
EARLY NEXT WEEK. ANOTHER COLD FRONT WILL APPROACH ON WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...THE LIKELIHOOD OF SHOWERS AND
THUNDERSTORMS INCREASES TODAY AS THE ATMOSPHERIC COLUMN MOISTENS
IN ADVANCE OF A SLOW MOVING COLD FRONT. MODEL SOUNDINGS SHOW THE
COLUMN BECOMING NEARLY SATURATED WITH P/W VALUES IN THE 2 INCH
RANGE BY THIS AFTERNOON. AT THE UPPER LEVELS A SERIES OF WEAK
DISTURBANCES MOVING ALONG THE LEADING EDGE OF AN H/5 LONGWAVE
TROUGH WILL ACT ON A MODERATELY UNSTABLE AND MOIST ATMOSPHERE TO
KEEP IN THE THREAT OF CONVECTION...WITH THE POSSIBILITY OF HEAVY
RAIN AND TRAINING STORMS THROUGH THE AFTERNOON AND EVENING HOURS.

EXTENSIVE CLOUD COVER AND LOWERING THICKNESS VALUES WILL ALLOW FOR
SIGNIFICANTLY LOWER DAYTIME TEMPERATURES THAN EXPERIENCED OVER THE
PAST COUPLE OF DAYS...ESPECIALLY INLAND. EXPECT HIGHS OF AROUND 90
MOST PLACES...WITH UPPER 80S CLOSER TO THE COAST.

MODEL CONSENSUS HAS FRONT STALLING OVER THE NORTHWESTERN PORTION OF
OUR CWA OVERNIGHT. THE FRONT WILL SERVE AS A CONTINUED FOCUS FOR
CONVECTION...SO WILL BE MAINTAINING LIKELY POPS WITH THE POSSIBILITY
OF HEAVY RAIN FOR TONIGHT. CONSIDERING RECENT MODEL PERFORMANCE HAVE
STAYED ON THE HIGH SIDE OF GUIDANCE FOR OVERNIGHT MINIMUMS. THIS
WILL GIVE US LOWS IN THE LOWER TO MID 70S MOST PLACES.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...FRIDAY CONTINUES TO LOOK VERY WET LOCALLY AS
ELEMENTS COMBINE TO PRODUCE WIDESPREAD CONVECTION WITH HEAVY RAIN.
AT THE SURFACE...A WEAKENING COLD FRONT WILL BE WAVERING ACROSS THE
CWA...AND THIS...ALONG WITH REMNANT OUTFLOW BOUNDARIES FROM
CONVECTION ON THURSDAY...WILL SERVE AS FOCI FOR UPDRAFTS ON FRIDAY.
ALOFT...SHEAR LINE DEMARCATING THE LONGWAVE TROUGH AXIS WILL SWING
OVERHEAD AND NORTHEAST DURING THE DAY...WHILE 300MB 100KT JET MOVES
OVER NEW ENGLAND...LEAVING THE CAROLINAS WITHIN THE FAVORABLE RFQ
DIFFLUENT REGION...IN A SETUP THAT RESEMBLES QUITE WELL A
MADDOX-TYPE EVENT FROM LITERATURE FOR HEAVY RAIN.

ALL THIS OCCURS IN A THERMODYNAMIC ENVIRONMENT CHARACTERIZED BY
SBCAPE OF 800-1000 J/KG...PWATS OVER 2 INCHES...AND WARM CLOUD
DEPTH APPROACHING 11 KFT. THE "LONG SKINNY" CAPE PROFILE SUGGESTS
EFFICIENT PRECIPITATION PROCESSES (LONGER PARCEL RESIDENCE TIMES
WITHIN STRONG COLLISION-COALESCENCE ENVIRONMENT) IN UPDRAFTS
FRIDAY AS WELL...SO ALL SIGNS POINT TO A VERY ACTIVE DAY WITH
HEAVY RAINFALL THE PRIMARY THREAT WITHIN THUNDERSTORMS. ALTHOUGH
DRIER AIR WILL SLOWLY BEGIN TO FILTER INTO THE MID-LEVELS AS AN
EMBEDDED SHORTWAVE PUSHES OFFSHORE LATE FRIDAY...STILL ANTICIPATE
A SIGNIFICANT QPF DAY...HIGHEST EASTERN HALF OF THE CWA. TEMPS
WILL BE TEMPERED BY THE WIDESPREAD CLOUDS AND RAIN...RISING ONLY
INTO THE MID/UPR 80S. LOWS AT NIGHT WILL DROP INTO THE MID 70S AT
THE COAST...BUT AROUND 70 WELL INLAND WHERE DRIER AIR WILL BECOME
MORE PRONOUNCED LATE.

SATURDAY WILL BE A TRANSITIONAL DAY AS RIDGING FROM THE SOUTHWEST
TRIES TO BLOSSOM ACROSS THE AREA. IT WILL GET SHUNTED EAST BY THE
AFOREMENTIONED LONGWAVE TROUGH...BUT THE WESTERLY FLOW BETWEEN THESE
TWO FEATURES WILL HELP TO DRY THE COLUMN FROM FRIDAY. AT THE SAME
TIME...THE SUBTLE THICKNESS INCREASE WILL HELP TO FURTHER ERODE THE
FRONT WHICH SHOULD BECOME INDISTINGUISHABLE ON SATURDAY.
HOWEVER...IT WILL CONTINUE TO HELP DRIVE CONVECTION...ALBEIT IN A
LESS SIGNIFICANT MANNER THAN FRIDAY. STILL ANTICIPATE SCATTERED
TSTMS SATURDAY AREA-WIDE...WITH TEMPS AGAIN JUST BELOW NORMAL IN
THE UPR 80S TO AROUND 90...AND LOWS A FEW DEGREES ABOVE 70.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...SEASONABLE CONDITIONS TO BEGIN THE PERIOD AS
RIDGING DEVELOPS ALOFT AND HIGH PRESSURE OFFSHORE RIDGES BACK
TOWARDS THE COAST. MID-LEVEL WESTERLY FLOW WILL CAUSE A RELATIVELY
DRY COLUMN ON SUNDAY...SO ONLY ISOLATED CONVECTION IS
ANTICIPATED...LIKELY LESS THAN CLIMATOLOGICALLY NORMAL. WITH HEIGHTS
BUILDING ALOFT AND RETURN FLOW DEVELOPING...TEMPS SUNDAY WILL WARM
TO SEASONABLE VALUES. THEREAFTER...HEAT WILL SLOWLY BUILD AGAIN
THROUGH TUESDAY THANKS TO SUBTLE THICKNESS INCREASE DOWNSTREAM OF A
LARGE TROUGH ACROSS THE MIDWEST...AND CONTINUED RETURN FLOW AT THE
SURFACE. THIS DRIVES MORE TYPICAL CONVECTION CHANCES
MONDAY/TUESDAY...BEFORE A COLD FRONT APPROACHES AND STALLS ACROSS
THE AREA BY WEDNESDAY. THIS WILL BRING MUCH MORE WIDESPREAD PRECIP
CHANCES FOR THE MIDDLE OF NEXT WEEK...ALONG WITH TEMPERATURES
COOLING BACK TO SEASONABLE LEVELS.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...PATCHY AREAS OF FOG OVERNIGHT COULD CREATE BRIEF-MVFR
INLAND...AND INCREASING CHANCES FOR ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS EXPECTED ON THURSDAY POSSIBLY CREATING MVFR/IFR
ESPECIALLY IN HEAVIER DOWNPOURS. OTHERWISE EXPECT VFR.

VFR PREVAILS WITH SOUTHWEST WINDS AOB 10 KTS AND SOME LINGERING
SHOWERS MOVING ACROSS THE INLAND PORTIONS OF THE FORECAST
AREA...HOWEVER DO NOT ANTICIPATE ANY RESTRICTIONS. PATCHY AREAS OF
FOG OVERNIGHT COULD CREATE BRIEF MVFR INLAND INTO THE EARLY MORNING
AS WELL BUT CONFIDENCE REMAINS LOW. AFTER DAYBREAK...EXPECT INCREASING
CLOUDS AND CHANCES FOR SHRA/TSRA THROUGHOUT THE DAY. HEAVY DOWNPOURS
ARE EXPECTED GIVEN THE FAVORABLE ENVIRONMENT...THUS ANTICIPATE
PERIODS OF MVFR/IFR. AS FOR WINDS...EXPECT SOUTH-SOUTHWEST WINDS AOB
10 KTS INLAND AND UP TO AROUND 15 KTS WITH GUSTS ALONG THE COAST.
INTO TO LATE EVENING HOURS...EXPECT SHRA/TSRA TO CONTINUE WITH
SOUTHWEST WINDS AOB 12 KTS.

EXTENDED OUTLOOK...A FRONT STALLS OVER THE REGION WITH A DECENT
CHANCE FOR CONVECTION THROUGH SATURDAY...MAINLY IN THE AFTERNOON.
MORE SHOWERS AND STORMS ARE POSSIBLE MONDAY. BRIEF IFR CONDITIONS
ARE POSSIBLE IN THE HEAVIER SHOWERS AND STORMS. OTHERWISE EXPECT VFR.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...SOUTHWESTERLY FLOW WILL CONTINUE OVER THE
WATERS THROUGH THE NEAR TERM AS HIGH PRESSURE OVER THE WESTERN
ATLANTIC INTERACTS WITH AN APPROACHING COLD FRONT WELL INLAND.
WINDS WILL STAY IN THE 10 TO 15 KT RANGE FOR MUCH OF THE
PERIOD...WITH SEAS AVERAGING 2 TO 4 FT.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...A WEAKENING COLD FRONT WILL WAVER IN THE
VICINITY THROUGH SATURDAY...LIKELY REMAINING JUST WEST OF THE
COASTAL WATERS DURING THIS PERIOD. THAT LEAVES A WEAK
GRADIENT...AND S/SE WINDS FRIDAY AND SATURDAY AT 10 KTS OR LESS.
LATE SATURDAY THE COLD FRONT WILL WASH OUT...AND AS HIGH PRESSURE
BECOMES DOMINANT OFFSHORE...WINDS WILL VEER TO BECOME MORE
SWLY...REMAINING AROUND 10 KTS. WAVE HEIGHTS WILL BE HIGHEST ON
FRIDAY...THANKS TO WINDS EASING FROM THURSDAY...WITH 3-4 FT SEAS
LIKELY ON A SOUTHERLY WIND CHOP. THESE HEIGHTS WILL DROP TO 1-3 FT
ON SATURDAY ON THE LIGHTER WINDS.

LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 330 AM THURSDAY...MORE TYPICAL SUMMERTIME PATTERN WILL DEVELOP
LATE IN THE WKND AND EARLY NEXT WEEK AS HIGH PRESSURE OFFSHORE
EXERTS ITS INFLUENCE ACROSS THE COASTAL WATERS. SW WINDS WILL SLOWLY
INCREASE THROUGH THE PERIOD...BECOMING 15-20 KTS LATE MONDAY. THE
COMBINATION OF THESE RISING WINDS AND AN AMPLIFYING GROUND SWELL
WILL DRIVE SEAS UP FROM 2-3 FT SUNDAY...TO 3-5 FT MONDAY...AND
CAUTIONARY STATEMENTS MAY BE NEEDED EARLY NEXT WEEK.

&&

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

&&

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








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