Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 302330
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
630 PM EST FRI JAN 30 2015

.SYNOPSIS...
DRY HIGH PRESSURE WILL MOVE OVERHEAD THE REGION SATURDAY BRINGING
COOL TEMPERATURES. A STORM SYSTEM WILL APPROACH SUNDAY...DRAGGING
A COLD FRONT ACROSS THE AREA ON MONDAY. THIS WILL BE ACCOMPANIED
BY RAINFALL...SOME OF WHICH MAY BE HEAVY AT TIMES SUNDAY NIGHT
INTO MONDAY. COLD HIGH PRESSURE WILL FOLLOW FOR TUESDAY. ANOTHER
STORM SYSTEM WILL BRING UNSETTLED WEATHER FOR THE REMAINDER OF THE
WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 630 PM FRIDAY...CLEAR SKIES NOW THAT THE SUN HAS SET.
TEMPERATURES ARE FALLING DOWN INTO THE MID 40S SO FAR BUT WITH
CONTINUED MIXING WE WILL SEE A MORE GRADUAL DECLINE THAN OTHERWISE
EXPECTED. FORECAST GOOD TO GO...NO CHANGES WITH LATEST UPDATE.
EXPECT CLEAR...COLD AND DRY FOR THE OVERNIGHT PERIOD. PREVIOUS
DISCUSSION FOLLOWS:

DIURNAL CUMULUS WILL PEEL OFF INTO THE LATE AFTERNOON LEAVING
CLEAR SKIES AND COLD AIR ADVECTION THIS EVENING AND OVERNIGHT.
WINDS WILL HOLD TEMPERATURES UP A BIT AS MIXING OFFSETS IDEAL
RADIATIONAL COOLING UNDER A CLOUDLESS DOME THROUGH EVENING.
DIMINISHING WINDS AFTER MIDNIGHT HOWEVER WILL ALLOW VERY GOOD
DROPS TO PREVAIL INTO PRE-DAWN...DIPPING INTO THE MIDDLE 20S OVER
MOST NE SC AND SE NC LOCATIONS. UPPER 20S TO AROUND 30 FOR OUR
COASTAL AND ICWW VENUES...AS WIND DIRECTION AFTER 6Z VEERS MORE TO
TRUE NORTH. WIND-CHILLS/APPARENT TEMPERATURES WILL REACH MINIMUM
VALUES IN THE UPPER TEENS TO AROUND 20 F BETWEEN 4AM-7AM.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...SPLIT FLOW ACROSS THE CONUS FOR THE WEEKEND
WILL KEEP THINGS MOVING QUICKLY FROM WEST TO EAST. THAT BEING
SAID...A DECENT RAIN EVENT IS SLATED TO BEGIN LATE SUNDAY AND
PERSIST BEYOND THE SHORT TERM.

SATURDAY WILL BY FAR BE THE BETTER OF THE TWO WEEKEND DAYS AS
POSITIVE THICKNESS ADVECTION OCCURS AS A SHORTWAVE RIDGE MOVES
OVERHEAD...IN CONJUNCTION WITH SURFACE HIGH PRESSURE BUILDING DOWN
FROM THE GREAT LAKES. THESE TWO FEATURES WILL CREATE AMPLE
SUNSHINE...BUT TEMPS WILL STAY BELOW NORMAL THANKS TO AN AIRMASS
ORIGINATING FROM A COLD REGION. HIGHS ON SATURDAY WILL STRUGGLE ONLY
INTO THE UPPER 40S TO LOW 50S...EVEN WITH AMPLE SUNSHINE. LATE
SATURDAY AND SATURDAY NIGHT MID-LEVEL FLOW BECOMES MORE AGGRESSIVELY
FROM THE SW AHEAD OF A NORTHERN STREAM SHORTWAVE DIVING INTO THE
MIDWEST. THIS WILL BEGIN MOST ADVECTION ALOFT...AND AN OVC MID-LEVEL
CLOUD DECK BY SUNDAY MORNING. THIS CLOUD COVER...COMBINED WITH
DEVELOPING RETURN FLOW AROUND THE DEPARTING SURFACE HIGH...WILL KEEP
MINS AROUND SEASONABLE VALUES...A DEGREE OR TWO EITHER SIDE OF 30.

WEATHER CONDITIONS WILL SLOWLY DETERIORATE DURING SUNDAY AS SURFACE
CYCLOGENESIS OCCURS BENEATH THE APPROACHING SHORTWAVE. ALTHOUGH THE
LOW WILL TRACK WELL NORTH OF THE LOCAL AREA...INCREASING MOISTURE
WILL CREATE LOWERING OVERCAST SKY CONDITIONS...AND BY LATE SUNDAY
AND ESPECIALLY SUNDAY NIGHT...RAIN WILL OVERSPREAD THE REGION FROM
THE SOUTH AND WEST. MOISTURE FROM A WIDE OPEN GULF OF MEXICO WILL BE
CARRIED BY THIS STORM SYSTEM...AND AN INCREASING LLJ WILL PUSH THE
CORE OF THETA-E RIDGE AXIS INTO THE EASTERN CAROLINAS LATE. IT IS
INTERESTING TO NOTE HOW 850MB MOISTURE TRANSPORT VECTORS FOLLOW THE
AREA OF EXPECTED HEAVIER PRECIP WITHIN THE STORM AS IT TRACKS
EAST...WHILE ELONGATING AS MORE GULF MOISTURE IS TAPPED INTO SUNDAY
NIGHT. ALTHOUGH THE BEST DYNAMICS WILL BE DISPLACED NORTH OF THE
CWA...SOME UPPER DIFLUENCE WITHIN THE APPROACH OF THE LFQ OF AN
UPPER JET WILL HELP DRIVE LIFT SUNDAY NIGHT. THIS LIFT IN A FULLY
SATURATED COLUMN WITH PWATS OVER THE 75TH PERCENTILE FOR
EARLY-FEBRUARY CREATES A SCENARIO WHERE SHOWERS WILL BECOME
WIDESPREAD...WITH PERIODS OF HEAVY RAINFALL. THE HEAVIEST RAINFALL
WILL OCCUR AFTER MIDNIGHT AND THEN INTO MONDAY...AND HAVE RAISED POP
TO CATEGORICAL.

STRONG WAA AHEAD OF THIS SYSTEM WILL BE TEMPERED BY CLOUDS AND
RAIN...AND THUS HIGHS WILL RISE ONLY INTO THE MID 50S. SUNDAY NIGHT
LOWS WILL FEATURE LITTLE DIURNAL VARIATION...AS CLOUDS/RAIN/WARM
WINDS HOLD LOWS IN THE UPR 40S TO AROUND 50.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...SHOWERS WILL BE UNDERWAY AT THE START OF THE
PERIOD THANKS TO AN APPROACHING COLD FRONT. OUR PLACEMENT IN THE
WARM SECTOR OF LOW PRESSURE OVER THE MID-ATLANTIC WILL RESULT IN
CONTINUED MOIST SOUTHWEST FLOW...AND THUS LIKELY POPS ACROSS THE
AREA FROM 7AM-1PM MON. QPF RANGES FROM AROUND ONE-TENTH OF AN INCH
INLAND TO AROUND ONE-QUARTER INCH ALONG THE COAST. THE FRONT SHOULD
BE NEAR OR OFF THE COAST JUST AFTER MIDDAY...BRINGING RAPID CLEARING
AND MUCH COOLER AIR INTO THE REGION. HIGH TEMPS...GENERALLY UPPER
50S TO AROUND 60...WILL BE REALIZED IN THE MORNING BEFORE CFP. LOWS
MONDAY NIGHT WILL PLUMMET INTO THE MID 20S AT MOST LOCATIONS AWAY
FROM THE BEACHES. COOL AND DRY HIGH PRESSURE WILL DOMINATE OUR
WEATHER ON TUE.

THE MIDDLE AND LATTER PORTIONS OF THE WEEK LOOK UNSETTLED...THOUGH
THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE DRIVING FEATURES. A
SOUTHERN STREAM SHORTWAVE OVER THE GULF COAST WILL INDUCE
CYCLOGENESIS OVER THE NORTHERN GULF ON WED. AHEAD OF THIS FEATURE...
MOIST OVERRUNNING COULD BRING SOME LIGHT RAIN TO OUR EXTREME
SOUTHERN ZONES EARLY WED MORNING. NO P-TYPE CONCERNS ATTM AS THE
COLDEST TEMPS WILL BE CONFINED TO OUR EXTREME NORTHERN ZONES WHERE
THE DRIEST MID-LEVEL AIR RESIDES. BY THE TIME PCPN SPREADS NORTHWARD
OVER THE CWA DURING THE DAY WED...TEMPS WILL BE WELL ABOVE FREEZING
ACROSS THE AREA. A COASTAL TROUGH WILL CONTINUE SHARPENING JUST
OFFSHORE THROUGH THE DAY WITH ENHANCED LIFT PROVIDED BY THE
SHORTWAVE TRACKING OVER THE SOUTHEAST. THE GFS/CMC ARE CONSIDERABLY
WETTER THAN THE ECMWF...SO WILL MAINTAIN CHC POPS ON WED. THE GFS
AND ECMWF SOLUTIONS DIVERGE LATE WED INTO THU...DEPENDING ON THE
TIMING OF A COLD FRONT DROPPING SOUTH FROM CANADA. THIS FRONT WILL
DICTATE HOW CLOSE THE GULF LOW TRACKS TO OUR COASTLINE. HAVE OPTED
FOR THE MORE PESSIMISTIC GFS/CMC DEPICTION THAT TRACKS THE GULF LOW
JUST OFFSHORE ON THU. EVEN AS POPS TAPER OFF LATE THU INTO FRI...
LOW STRATUS WILL PERSIST DURING FRI AS NORTHERLY SFC FLOW IS OVERRUN
BY MOIST SOUTHWEST FLOW ALOFT.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z... VFR EXPECTED THROUGH THIS TAF VALID PERIOD. NW WINDS
THIS EVENING WILL GRADUALLY VEERING TO THE N AFTER MIDNIGHT AND
DECREASE TO AOB 5 KT BY SUNRISE. DESPITE LIGHT WINDS AROUND SUNRISE
TEMPERATURE/DEWPOINT SPREADS OF AT LEAST 8 DEGREES OR MORE ENSURE NO
FOG DEVELOPMENT. N WINDS SATURDAY MORNING WILL GRADUALLY BECOME W-SW
IN THE AFTERNOON AS A HIGH PRESSURE AXIS SHIFTS OFFSHORE. SOME
INCREASING CI EXPECTED IN THE AFTERNOON.

EXTENDED AVIATION OUTLOOK...EXTENDED OUTLOOK...SHOWERS/MVFR LIKELY
LATE SUN THROUGH MON MORNING...THEN BECOMING VFR AGAIN THROUGH TUE.
POSSIBLE RAIN WED.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM FRIDAY...LATEST OBS SHOW CONTINUED NW WINDS IN THE 20
TO 25 KT RANGE WITH 3 TO 5 FT SEAS MOST LOCATIONS. SMALL CRAFT
ADVISORY CONTINUES AS PREVIOUSLY ADVERTISED. NO CHANGES WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:

ADVISORY CONDITIONS WILL CONTINUE OVERNIGHT AS BLUSTERY NW-N WINDS
TEAR ACROSS THE WATERS. OFFSHORE WINDS WILL RESULT IN LIMITED WAVE
GROWTH BUT 22-29 KT GUSTS WILL PREVAIL FOR MUCH OF THE NIGHT
ACROSS ALL THE WATERS BEFORE A DECREASING WIND SPEED TREND INTO
PRE-DAWN HOURS OF SATURDAY. WE SHOULD BE ABLE TO DROP THE ADVISORY
AROUND OR JUST BEFORE FIRST LIGHT SATURDAY. NO TSTMS OR
RESTRICTIONS TO VISIBILITY EXPECTED THROUGH TONIGHT.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...NW WINDS TO START SATURDAY WILL EASE THROUGH
THE DAY AS HIGH PRESSURE BUILDS TOWARDS THE WATERS. THIS HIGH
PRESSURE WILL MOVE DIRECTLY OVERHEAD THE WATERS SATURDAY NIGHT...SO
WINDS ARE EXPECTED TO BECOME JUST LIGHT AND VARIABLE SATURDAY
EVENING INTO SUNDAY MORNING. AS THIS HIGH PUSHES OFFSHORE SUNDAY...A
COLD FRONT WILL APPROACH FROM THE WEST...CAUSING THE GRADIENT TO
TIGHTEN...AND SW WINDS WILL INCREASE STEADILY SUNDAY. WIND SPEEDS
WILL RISE FROM AROUND 10 KTS EARLY SUNDAY...TO 20-25 KTS SUNDAY
NIGHT. THESE WINDS WILL DRIVE WAVE HEIGHTS QUICKLY UP TO 5-9 FT LATE
SUNDAY NIGHT...AFTER BEING JUST 1-2 FT MOST OF SATURDAY. A SMALL
CRAFT ADVISORY WILL LIKELY BE NEEDED THE LAST HALF OF SUNDAY.

LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...SMALL CRAFT ADVISORY CONDITIONS EXPECTED AT
THE START OF THE PERIOD WITH SOUTHWEST WINDS 20-25 KT AND GUSTS TO
30 KT AHEAD OF A COLD FRONT. SEAS WILL RUN IN THE 5-8 FT RANGE...
BECOMING 4-7 FT AFTER MIDDAY WITH WINDS VEERING TO THE NORTHWEST
BEHIND THE FRONT. SHOWERS ARE EXPECTED MAINLY DURING THE MORNING AND
EARLY AFTN HOURS. N-NW WINDS WILL REMAIN AROUND 20 KT WITH HIGHER
GUSTS MON NIGHT AS COLD AIR ADVECTS OVER THE WATERS. SCA CONDITIONS
SHOULD COME TO AN END JUST AFTER MIDNIGHT. EXPECT N-NE WINDS 10-15
KT ON TUE WITH SEAS SUBSIDING TO 2-3 FT. EAST WINDS AOB 10 KT ON WED
MORNING WILL STRENGTHEN DURING THE DAY AS A COASTAL TROUGH SHARPENS
OFFSHORE AND THE GRADIENT TIGHTENS OVER THE WATERS. SEAS WILL BUILD
TO 3-5 FT...POSSIBLY 6 FT OVER THE OUTER WATERS BY THE END OF THE
PERIOD.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST SATURDAY FOR AMZ250-252-
     254-256.

&&

$$

SYNOPSIS...JDW
NEAR TERM...MJC/REK
SHORT TERM...JDW
LONG TERM...BJR
AVIATION...MRR
MARINE...MJC/REK/JDW/BJR




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