Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 141122
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
722 AM EDT MON JUL 14 2014

.SYNOPSIS...
HOT AND HUMID CONDITIONS EXPECTED TODAY AND TUESDAY...AS HEAT
INDICES CLIMB ABOVE 100 DEGREES BOTH DAYS. AN UNSEASONABLY STRONG
COLD FRONT WILL APPROACH TUESDAY...BRINGING A GOOD CHANCE FOR
THUNDERSTORMS...SOME OF WHICH MAY BE STRONG TO SEVERE. THIS COLD
FRONT WILL MOVE OFFSHORE WEDNESDAY AND THURSDAY WITH COOLER BUT
STILL UNSETTLED CONDITIONS. A LOW PRESSURE WEST OF THE AREA WILL
DRIVE THIS FRONT BACK NORTH FRIDAY THROUGH NEXT WEEKEND...BRINGING
A RETURN TO SEASONABLE TEMPERATURES BUT STILL GOOD CHANCES FOR
SHOWERS AND THUNDERSTORMS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 7 AM MONDAY...CONVECTION HAS REMAINED OFFSHORE SO HAVE
DROPPED POP ALONG THE COAST FOR THIS MORNING. OTHERWISE THE
FORECAST REMAINS ON TRACK WITH LIMITED CHANGES REQUIRED FOR THE
MORNING UPDATE.

PREVIOUS DISCUSSION FOLLOWS:
AS OF 215 AM MONDAY...AS HAS BEEN THE CASE THE LAST FEW NIGHTS
CONVECTION IS STARTING TO DEVELOP OFFSHORE. THE DIFFERENCE FROM
DAYS PAST WILL BE THE AMOUNT OF DRY AIR IN THE MID LEVELS. WATER
VAPOR IMAGERY SHOWS LITTLE IN THE WAY OF DRY AIR WHICH IS
SUPPORTED BY FORECAST SOUNDINGS. THIS SHOULD ALLOW MORE OF THE
OFFSHORE ACTIVITY TO SPREAD ONSHORE CLOSER TO
DAYBREAK...ESPECIALLY GIVEN SOUTH TO SOUTHWEST FLOW IN PLACE. ANY
CONVECTION OVER THE WATERS AND ALONG THE IMMEDIATE COAST WILL WIND
DOWN WITHIN A FEW HOURS OF SUNRISE.

SIGNIFICANT INCREASE IN DEEP MOISTURE FROM YESTERDAY WITH
PRECIPITABLE WATER VALUES APPROACHING 2 INCHES LATE IN THE DAY AND
PRESENCE OF SEA BREEZE AND PIEDMONT TROUGH WILL LEAD TO AFTERNOON
SHOWER AND THUNDERSTORM DEVELOPMENT. INITIAL ACTIVITY WILL BE ALONG
THE SEA BREEZE WHICH WILL BE MORE OF A RESULTANT GIVEN SOUTHWEST
FLOW. THIS WILL KEEP ACTIVITY CLOSER TO THE COAST AT FIRST BUT
THEN AS OUTFLOW FROM INITIAL CONVECTION SPREADS INLAND COVERAGE
MAY EXPAND. MID LEVEL LAPSE RATES REMAIN QUITE WEAK AND THERE IS
STILL SOME SUBSIDENCE TO OVERCOME SO COVERAGE MAY NOT FALL SHORT
OF CLIMO...30 PERCENT. LATER IN THE DAY PIEDMONT TROUGH ACTIVITY
WILL SPREAD INTO WESTERN AREAS BEFORE WEAKENING WITH THE LOSS OF
HEATING THIS EVENING.

HOT TEMPERATURES WILL CONTINUE TODAY WITH WARM ADVECTION PUSHING
HIGHS INTO THE LOW TO MID 90S INLAND. CLOSER TO THE COAST HIGHS
WILL BE IN THE UPPER 80S TO LOWER 90S. LOW LEVEL MOISTURE
ADVECTION THIS AFTERNOON WILL MAINTAIN DEWPOINTS IN THE 70S WHICH
COMBINED WITH HIGHS IN THE 90S WILL PUSH HEAT INDEX VALUES CLOSE
TO 105 DEGREES. FOR NOW LOOKS LIKE THE AREA WILL FALL JUST SHORT
OF HEAT ADVISORY CRITERIA SO HAVE NO PLANS TO ISSUE ONE AT THIS
TIME.

SOUTHERLY FLOW CONTINUES TO PUMP WARM/MOIST AIR INTO THE REGION
OVERNIGHT. ISOLATED NOCTURNAL CONVECTION OVER THE WATERS/ALONG
THE COAST IS AGAIN LIKELY SO HAVE MAINTAINED LOW POP FOR THESE
AREAS. LINGERING DEBRIS CLOUD ALONG THE LOW LEVEL MOIST FLOW WILL
KEEP LOWS ABOVE CLIMO TONIGHT. MOST AREAS WILL REMAIN IN THE MID
TO UPPER 70S.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM MONDAY...ACTIVE AND CHANGEABLE WEATHER FOR THE SHORT
TERM AS THE AREA TRANSITIONS FROM HOT AND HUMID WEATHER...TO COOL
AND UNSETTLED. TUESDAY WILL BEGIN HOT AS CONTINUED RETURN FLOW
AROUND OFFSHORE HIGH PRESSURE ADVECTS WARM/HUMID AIR INTO THE
CAROLINAS. THIS WILL DRIVE TEMPS INTO THE 90S AGAIN...WITH HEAT
INDICES SOARING TO ABOVE 100 IN MOST LOCATIONS. THIS HEAT WILL SERVE
AS FUEL FOR CONVECTION LATER ON TUESDAY AS THE COLD FRONT APPROACHES
FROM THE NORTHWEST...AND SPC HAS OUTLINED THE AREA IN A SLIGHT RISK
FOR TUESDAY. INSTABILITY WILL BE HIGH...AND SOME STORM ORGANIZATION
IS POSSIBLE AHEAD OF THE FRONT. AS HEIGHT FALLS OCCUR THROUGH THE
AFTN/EVE...MID-LEVEL LAPSE RATES INCREASE...SO EXPECT THERE IS AT
LEAST SOME CHANCE FOR SEVERE WIND...MOST LIKELY OCCURRING AS WET
MICROBURSTS THANKS TO PWATS OVER TWO INCHES.

THIS FRONT WILL STALL ACROSS THE CWA ON WEDNESDAY...WHICH WILL KEEP
HIGH CHANCES FOR PRECIP AND CLOUDS THROUGH THE DAY. AS THE STRONG
UPPER TROUGH DRIVING THIS FEATURES SLOWLY LIFTS OFF TO THE NE...THE
POSITIVE TILT WILL MAINTAIN SW FLOW ALOFT AND THUS HIGH PWATS WILL
PERSIST ON WEDNESDAY. TEMPS WILL BE MUCH COOLER ON WEDNESDAY DUE TO
LOWERED THICKNESSES AND AT LEAST WEAK COOL ADVECTION...REACHING ONLY
THE MID 80S. PRECIP WILL BE WIDESPREAD THE FIRST HALF OF
WEDNESDAY...BUT GUIDANCE IS NOW MORE AGGRESSIVE WITH THE (STILL
SLOW) PROGRESSION OF THE FRONT...AND DRIER AIR WILL WORK INTO THE
AREA WEDNESDAY NIGHT...BRINGING MUCH DECREASED POP OVERNIGHT.

LOWS TUESDAY NIGHT WILL BE VERY WARM...FALLING ONLY INTO THE MID AND
UPR 70S. LOWS WEDNESDAY NIGHT WILL BE MUCH COOLER THANKS TO DRIER
AIR AND THE COLD FRONT...DROPPING TO AROUND 70 AT THE COAST...WITH
UPPER 60S LIKELY INLAND.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...ANOMALOUSLY STRONG UPPER TROUGH WILL BE
PUSHING A COLD FRONT THROUGH THE AREA EARLY THURSDAY...AND
GUIDANCE NOW AGREES THAT THE TROUGH IS STRONG ENOUGH TO PUSH THE
FRONT ENTIRELY OFFSHORE THURSDAY. THIS IS GOOD NEWS IN TERMS OF
LOCAL SENSIBLE WEATHER...SINCE IT NOW LOOKS LIKE THURSDAY MAY END
UP BEING A SUNNY AND DRY...AND PLEASANT...DAY WITH TEMPS IN THE
80S. THIS WILL BE SHORT LIVED HOWEVER...AS A LOW PRESSURE DEVELOPS
SW OF THE AREA ALONG THE STALLED BOUNDARY. THIS WILL BEGIN TO PULL
THE FRONT BACK TOWARDS THE AREA ON FRIDAY...ONCE AGAIN INCREASING
CHANCES FOR SHOWERS AND THUNDERSTORMS. THE FRONT WILL SLOWLY LIFT
NORTH DURING THE WEEKEND...ALLOWING FOR TEMPS TO RECOVER TO MORE
SEASONABLE LEVELS BY SUNDAY...BUT POP FOR CONVECTION WILL REMAIN
ABOVE CLIMATOLOGICAL NORMS.

&&

.AVIATION /11Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...LAND BREEZE BOUNDARY CAN BE SEEN IN RADAR IMAGERY
OFFSHORE OF THE COASTAL TERMINALS MOVING EAST. SHOWERS ALONG THE
BOUNDARY HAVE BEEN DECREASING OVER THE PAST SEVERAL HOURS. WINDS ARE
WSW-W BEHIND THE BOUNDARY. STRATUS IS SPREADING EAST AND IS
AFFECTING KFLO THIS MORNING.

VFR SHOULD DEVELOP AT KFLO BY 14Z. THERE IS A CHANCE OF IFR CIGS AT
KLBT THROUGH 14Z BUT CONFIDENCE IS LOW. OTHERWISE VFR EXPECTED
THIS MORNING ALTHOUGH THERE COULD BE A SHORT PERIOD OF MVFR CIGS AS
THE SEA BREEZE BOUNDARY DEVELOPS AND SHIFTS THROUGH THE COASTAL
TERMINALS. WIND DIRECTIONS TODAY WILL BE WSW-W...BECOMING SW EXCEPT
BECOMING S-SSW AT THE COASTAL TERMINALS 16-17Z. THERE IS A CHANCE OF
SHOWERS AND THUNDERSTORMS TODAY. LIFT IS NOT IMPRESSIVE AND THINK
THE BEST CHANCES NEAR THE COASTAL TERMINALS 16-20Z...AND KFLO/KLBT
AFTER 21Z.

EXTENDED OUTLOOK...SHOWERS/TSTMS/TEMPO MVFR LIKELY TUESDAY AND
WEDNESDAY AS A COLD FRONT STALLS OVER THE EASTERN CAROLINAS. CHANCE
OF SHOWERS/TSTMS CONTINUES THROUGH FRIDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 7 AM MONDAY...SOUTHWEST FLOW CONTINUES BETWEEN 10 AND 15 KT
ACROSS THE WATERS. ISOLATED CONVECTION HAS DEVELOPED BUT HAS SO
FAR HAD LIMITED IMPACT ON THE WATERS. NO MAJOR CHANGES NEEDED FOR
MORNING UPDATE.

PREVIOUS DISCUSSION FOLLOWS:
AS OF 215 AM MONDAY...GRADIENT WILL BECOME MORE DEFINED DURING
THE DAY TODAY AS BERMUDA HIGH EXTENDS WEST AND PIEDMONT TROUGH
DEVELOPS. CURRENT FORECAST KEEPS WINDS/SEAS BELOW SCEC THRESHOLDS
THROUGH THE PERIOD. FLOW WILL REMAIN SOUTHWEST WITH SPEEDS RISING
INTO THE 15 TO 20 KT RANGE LATER THIS AFTERNOON AND CONTINUING
OVERNIGHT AS WEAK LOW LEVEL JET DEVELOPS AND GRADIENT REMAINS
PINCHED. SEAS AROUND 3 FT THIS MORNING WILL BUILD TO 3 TO 4 FT
LATER TODAY AND 3 TO 5 FT THIS EVENING AND OVERNIGHT.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM MONDAY...HIGH PRESSURE OFFSHORE WILL CONTINUE SW RETURN
FLOW LOCALLY THROUGH THE SHORT TERM...WITH INCREASING STRENGTH AS
THE GRADIENT TIGHTENS AHEAD OF A STRONG COLD FRONT. THIS FRONT WILL
LIKELY CROSS INTO THE COASTAL WATERS VERY LATE WED NIGHT...CAUSING
WINDS TO EASE AND VEER TO THE WEST. OTHERWISE...ANTICIPATE WIND
SPEEDS OF 15-25 KTS FROM THE SW THROUGH THE PERIOD. THESE STRONG
WINDS WILL PUSH WAVE HEIGHTS UP TO 6 FT TUESDAY AFTN THROUGH WED
MORNING...BEFORE SEAS FALL LATE WEDNESDAY. THE ELEVATED SEAS AND
STRONG WINDS WILL LIKELY REQUIRE AN SCA THIS PERIOD.

LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 330 AM MONDAY...COLD FRONT WILL BE POSITIONED JUST EAST OF THE
WATERS FIRST THING THURSDAY MORNING...WITH LIGHT W/NW WINDS
WIDESPREAD. THIS FRONT WILL WAVER AND LIFT BACK TO THE NW DURING
THURSDAY AND FRIDAY...SO THE MAJORITY OF THE EXTENDED WILL FEATURE
SOUTHERLY WINDS AROUND 10 KTS ON THE EAST SIDE OF THIS WEAK
BOUNDARY. OTHER THAN A VERY BRIEF PERIOD OF WESTERLY WIND
CHOP...SEAS THURSDAY AND FRIDAY WILL BE 2-4 FT WITH A SOUTHERLY 5
SEC WIND WAVE PREDOMINANT IN THE SPECTRUM.

&&

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

&&

$$
SYNOPSIS...JDW
NEAR TERM...III
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...III/BJR
MARINE...III/JDW






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