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 281450
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1050 AM EDT MON JUL 28 2014

.SYNOPSIS...
HIGH HEAT AND HUMIDITY WILL PREVAIL TODAY AHEAD OF AN UNSEASONABLY
STRONG COLD FRONT. THE FRONT IS EXPECTED TO BRING THUNDERSTORMS
LATER THIS AFTERNOON AND EVENING...AND SOME MAY BE SEVERE. DRIER
AND COOLER AIR WILL SETTLE INTO THE REGION IN WAKE OF FRONT MUCH
OF THIS WEEK...AS CANADIAN HIGH PRESSURE DROPS INTO THE REGION.
RAIN CHANCES WILL RETURN BY NEXT WEEKEND AS HIGH PRESSURE OFFSHORE
BUILDS WEST AND BRINGS A RETURN OF MOISTURE TO THE EAST COAST.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM MONDAY...MORNING CLOUD COVER HAMPERING OTHERWISE
RAPID MORNING TEMPERATURE CLIMBS ACROSS THE AREA...BUT THE DEBRIS
CLOUD COVER IS THINNING AND SOON SURFACE-BASED CAPES WILL RAMP UP.
H5 TEMPS HAVE DROPPED ONLY SLIGHTLY AND WILL REMAIN AROUND -7
DEGREES MUCH OF THE DAY. STRONGER HEIGHT FALLS AND COOLING ALOFT
FOLLOW MAINLY INTO EARLY TUESDAY. STILL...THESE FACTORS COULD
BRING MORE OF A HAIL THREAT INTO EARLY EVENING ...AS HIGH SFC
CAPES AND UPPER COOLING OVERLAP. SPC RETAINS A SLIGHT RISK OVER
OUR AREA DUE TO GOOD FORCING ALOFT WITH THE APPROACHING AND
UNUSUALLY AMPLIFIED UPPER TROUGH...AND ASSOCIATED ROBUST BULK
SHEAR PARAMETERS. WITH INCREASING SUN...IGNITION OF STORMS IS
EXPECTED. THE SEA BREEZE WILL ALSO INTERTWINE IN THE MIX TO ADD
LOW-LEVEL BOOSTS SO THIS FEATURE WILL ALSO SERVE AS A FOCAL POINT
FOR STORM INITIATION.

STORM MOTION AND DOWNDRAFT CAPE PARAMETERS WILL ENHANCE POTENTIAL
FOR DAMAGING WINDS GUSTS...THROUGH A FORWARD MOTION CLOSE TO 30
MPH AND EVAPORATIVE COOLING TO INCREASE DOWNDRAFT POWER. ANYTIME
AFTER 18Z SEEMS FAIR GAME FOR DISCREET STRONG STORMS...THEN A MORE
ORGANIZED SQUALL OR BROKEN LINE OF STORMS WITHIN THE MAIN VORT
SPOKE EMBEDDED IN THE UPPER TROUGH THIS EVENING. ACTUAL FRONTAL
PASSAGE SLATED LATE TONIGHT AND A WIND-SHIFT TO THE NORTH LOOKS
TO CLEAR THE COAST BY DAYBREAK TUESDAY.

HEAT ADVISORY CONTINUES FOR PORTIONS OF SC FOR MAXIMUM APPARENT
TEMPERATURES OF 105-108 THIS AFTERNOON.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...COLD FRONT WILL BE OFF THE COAST BY THE START OF
THE PERIOD WITH A MARKEDLY DIFFERENT AIR MASS BUILDING OVER THE
REGION. FLAT MID LEVEL TROUGH WILL REMAIN JUST WEST OF THE AREA
DURING THE PERIOD. LOW LEVEL NORTHERLY FLOW AND MID LEVEL
WEST-NORTHWEST FLOW WILL USHER IN MUCH DRIER AIR. PRECIPITABLE WATER
VALUES DROP TO AROUND 1 INCH TUE/WED WITH DEWPOINTS IN THE UPPER 50S
TO LOWER 60S EACH DAY. PRECIP CHANCES WILL BE CLOSE TO ZERO EACH
DAY. ALTHOUGH GRADIENT WILL BE VERY WEAK THERE WILL NOT BE MUCH IF
ANY SEA BREEZE GIVEN WATER TEMPS WITHIN A FEW DEGREES OF HIGHS...MID
80S. TUE SHOULD BE THE WARMER DAY...MAINLY DUE TO A WARMER START.
LOWS WILL DROP INTO THE MID TO UPPER 60S EACH NIGHT. THERE WILL BE
POTENTIAL FOR RADIATIONAL COOLING WITH LIGHT WINDS...CLEAR
SKIES...AND DRY AIR ALOFT. TYPICAL COLD SPOTS COULD DROP INTO THE
LOWER 60S.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 AM MONDAY...MID LEVEL TROUGH HANGING OVER THE EASTERN CONUS
FOR MUCH OF THE PERIOD WILL KEEP COLD FRONT STALLED OFF THE
SOUTHEAST COAST INTO THE WEEKEND. ALTHOUGH DEEP MOISTURE IS LACKING
THERE COULD BE A FEW SHORTWAVES ROTATING AROUND THE BASE OF THE
TROUGH THU INTO FRI...EACH PROVIDING A BRIEF INCREASE IN MID LEVEL
MOISTURE. THESE COULD SPAWN SOME ISOLATED AFTERNOON/EVENING
SHOWERS...IF TIMING IS FAVORABLE. COVERAGE WOULD BE FAIRLY LIMITED
SO AT MOST PLAN TO CARRY A SILENT POP.

DEEPER SOUTHWEST FLOW DEVELOPS FRI AND CONTINUES THROUGH THE WEEKEND
AS 5H TROUGH DIGS. GULF MOISTURE ADVECTED INTO THE SOUTHEAST LATE IN
THE WEEK PUSHES PRECIPITABLE WATER VALUES OVER 1.5 INCHES LATER FRI
AND CLOSE TO 2 INCHES BY THE END OF THE PERIOD. INCREASING DEEP
MOISTURE...POSSIBILITY OF SHORTWAVES AND DIURNAL INSTABILITY WILL
ALL CONTRIBUTE TO AN INCREASE IN POP FRI-SUN. THERE ALSO REMAINS THE
SPECTER OF POTENTIAL LOW PRESSURE DEVELOPMENT ALONG THE FRONT
STALLED OFF THE SOUTHEAST COAST. FOR NOW THE MAJOR MEDIUM RANGE
GUIDANCE KEEPS THIS FEATURE QUITE WEAK BUT DEVELOPMENT OF SAID
FEATURE WOULD NOT BE UNPRECEDENTED AND IS SOMETHING TO WATCH.
TEMPERATURES THROUGH THE PERIOD WILL REMAIN BELOW CLIMO WITH HIGHS
IN THE MID TO UPPER 80S AND LOWS IN THE MID TO UPPER 60S.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 14Z...SHORT-LIVED MVFR/IFR POSSIBLE IN ISOLATED STRONG
STORMS LATER THIS AFTERNOON AND EVENING. OTHERWISE EXPECT VFR.

LATEST SATELLITE IMAGERY DEPICTS OVERALL SCT SKIES THIS
MORNING...MAINLY HIGH CLOUDS...AS A DISTURBANCE CONTINUES TO WEAKEN
ACROSS THE CAROLINAS. CHANCES INCREASE FOR ISOLATED STRONG TO SEVERE
STORMS LATER THIS AFTERNOON AND EVENING AS A COLD FRONT APPROACHES
THE AREA. AHEAD OF THE FRONT...WE WILL SEE SOUTHWEST WINDS INCREASE
THROUGHOUT THE MORNING HOURS...WITH SUSTAINED WINDS 10 TO 12 KTS AND
GUSTS UP TO 20 KTS BY EARLY AFTERNOON. COULD NOT ENTIRELY RULE OUT
SHORT-LIVED PERIODS OF MVFR/IFR WITH THE CONVECTION AS STRONGER
STORMS MAY PRODUCE HEAVY DOWNPOURS AT TIMES. THE FRONT WILL PUSH
OFFSHORE TONIGHT ALLOWING FOR CONVECTION TO TAPER OFF AND SKIES
BEGIN TO GRADUALLY CLEAR...GIVING WAY TO VFR WITH VEERING WINDS TO
THE NORTHWEST...WITH SUSTAINED WINDS AOB 10 KTS THROUGH THE END OF
THE VALID TAF PERIOD.

EXTENDED OUTLOOK...MVFR DUE TO MORNING FOG POSSIBLE THURSDAY AND
FRIDAY. OTHERWISE EXPECT VFR.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 AM MONDAY...SMALL CRAFT EXERCISE CAUTION FOR ALL
WATERS THROUGH TONIGHT. THE SFC PRESSURE PATTERN AND TIGHTENED
GRADIENT AHEAD OF THE APPROACHING COLD FRONT REMAINS CONDUCIVE FOR
SW-WSW WINDS AT A SOLID 15 TO 20 KT WITH SOME GUSTS UP TO 25 KT.
DURING THE APPROACH AND PASSAGE OF THE COLD FRONT TONIGHT...WINDS
WILL VEER FROM WSW TO NW INITIALLY...THEN FURTHER VEER TO THE N TO
NNE BY DAYBREAK TUESDAY. THE SFC PG WILL BEGIN TO RELAX SOME
TOWARD DAYBREAK TUESDAY...AND FURTHER RELAX EARLY IN THE SHORT
TERM. WINDS WILL SUBSIDE TO AROUND 15 KT AFTER MIDNIGHT TONIGHT.
SIGNIFICANT SEAS WILL RANGE BETWEEN 3 AND 5 FT TODAY INTO THIS
EVENING...AND ONLY DROP TO 2 TO 4 FT LATE TONIGHT AFTER THE CFP.
WIND DRIVEN WAVES OR CHOP WILL DOMINATE THE SIGNIFICANT SEAS
SPECTRUM WITH DOMINATING PERIODS OF ONLY 5 TO 6 SECONDS. STRONG TO
POSSIBLY SEVERE CONVECTION MAY AFFECT THE LOCAL WATERS LATE THIS
AFTERNOON AND TONIGHT...AHEAD OF THE APPROACHING COLD FRONT.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...BRIEF NORTHERLY SURGE FOLLOWING THE COLD FRONT
WILL BE WANING AS THE PERIOD BEGINS. WINDS MAY BE 10 TO 15 KT TUE
MORNING BUT BY MIDDAY NORTHEAST FLOW SHOULD BE 10 KT OR LESS. WINDS
REMAIN 10 KT OR LESS WED BUT MAY BECOME SLIGHTLY MORE ONSHORE DURING
THE AFTERNOON. SEA BREEZE IS NOT LIKELY TO BE A FACTOR EITHER DAY
GIVEN THE BELOW NORMAL FORECAST HIGHS. HOWEVER...THERE WILL BE
POTENTIAL FOR A WELL DEFINED LAND BREEZE EACH NIGHT AS LOWS OVERLAND
DROP INTO THE 60S. SEAS WILL RUN 2 TO 3 FT THROUGH THE PERIOD...WITH
HIGHEST SEAS EXPECTED DURING THE FIRST HALF OF TUE.

LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 AM MONDAY...STALLED FRONT EAST OF THE WATERS AND HIGH
PRESSURE TO THE WEST WILL MAINTAIN LIGHT NORTHEAST TO EAST FLOW OVER
THE WATERS THROUGH THE PERIOD. SPEEDS WILL GENERALLY BE AROUND 10 KT
WITH SEAS RUNNING 2 TO 3 FT.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR SCZ032-033-039-
     053>056.

NC...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...MJC
NEAR TERM...MJC
SHORT TERM...III
LONG TERM...III
AVIATION...SGL
MARINE...DOUG/3




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