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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 051631
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1131 AM EST THU MAR 5 2015

.SYNOPSIS...
A POWERFUL COLD FRONT WILL BRING SHARPLY COLDER TEMPERATURES
BEGINNING THIS EVENING. THERE IS A CHANCE OF SOME LIGHT FROZEN
PRECIPITATION FRIDAY MORNING. THE WEEKEND WILL FEATURE SLOWLY
MODERATING TEMPERATURES. THE SLOW WARMUP WILL CONTINUE NEXT WEEK
WITH SHOWERS POSSIBLE.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 1030 AM...THIS UPDATE IS MAINLY CONCERNED WITH THE
INCREASING AREAL COVERAGE AND PROGRESSION OF THE SEA FOG INLAND.
CURRENTLY THE SEA FOG IS DEVELOPING ACROSS THE LOCAL COASTAL
WATERS WHERE SSTS ARE IN THE 40S. THIS FOG WILL PLAGUE THE
IMMEDIATE COAST WITH VSBYS REDUCED TO 1 NM OR LESS. THIS FOG WILL
LIMIT THE DAYS INSOLATION FROM REACHING THE SFC. AS A RESULT...MAX
TEMPS ALONG THE IMMEDIATE COAST WILL BE LOWERED BY A CAT OR 2.
ELSEWHERE...THE CURRENT FCST MAX TEMPS THIS AFTERNOON STILL LOOK
AOK.

PREVIOUS DISCUSSION.............................................
AS OF 630 AM THURSDAY...LOTS OF INTERESTING WEATHER OVER
THE NEXT 24 HOURS. IT BEGINS WITH MOIST SOUTHWEST WINDS PRODUCING
SEA FOG ACROSS THE COASTAL WATERS AND ADJACENT LAND AREAS.
ASOS/AWOS OBS AT KCRE AND KSUT HAVE SHOWN LOW VSBYS ALL
MORNING...AND THIS SHOULD CONTINUE THROUGH ABOUT NOON. AS WE SAW
YESTERDAY...THIS SAME AIRMASS ALSO HAPPENS TO BE EXCEPTIONALLY
WARM. EVEN THOUGH MID-LEVEL CLOUDS WILL BE INCREASING ALONG THE
I-95 CORRIDOR THIS MORNING AND SPREADING DOWN TO THE COAST THIS
AFTERNOON THERE SHOULD STILL BE ENOUGH SUNSHINE TO PUSH TEMPS INTO
THE UPPER 70S TO LOWER 80S EAST OF I-95. SEVERAL THOUSAND FEET OF
VERTICAL MIXING SHOULD TAP STRONGER WINDS ALOFT WITH GUSTS
INCREASING TO 30-40 MPH LATE THIS MORNING. ALONG THE SOUTH- OR
SOUTHEAST-FACING BEACHES...COOL ONSHORE WINDS WILL KEEP
TEMPERATURES ~10 DEGREES COOLER.

A POWERFUL COLD FRONT STILL SHARPENING UP THROUGH THE SOUTHERN
APPALACHIANS AND ACROSS SOUTHERN VIRGINIA WILL SAG SOUTHWARD INTO
THE AREA THIS AFTERNOON. MODEL TRENDS OVER THE PAST FEW DAYS HAVE
BEEN FOR A SLOWER ARRIVAL OF THIS FRONT...AND IT NOW APPEARS THE
FRONT SHOULD ARRIVE IN BENNETTSVILLE-LUMBERTON-ELIZABETHTOWN AROUND
3 PM...FLORENCE-MARION-SOUTHPORT AND WILMINGTON BETWEEN 4-5 PM...AND
SOUTHWARD ACROSS MYRTLE BEACH-GEORGETOWN-KINGSTREE BETWEEN 5-6 PM.
THE TEMPERATURE DROP BEHIND THIS FRONT WILL BE PHENOMENAL: UPWARDS
OF 15 DEGREES IN THE FIRST HOUR AFTER FROPA WITH A 35-40 DEGREE DROP
OVER A 6 HOUR PERIOD GOING INTO THIS EVENING.

BEHIND THE SURFACE FRONT LIGHT TO OCCASIONALLY MODERATE RAIN SHOULD
DEVELOP AND LAST INTO THE EVENING HOURS. THIS RAIN WILL BE DUE TO
ISENTROPIC LIFT ALONG THE 300K SURFACE WHICH SHOULD HAVE A FAIR
AMOUNT OF SLOPE OVER THE INCREASINGLY COLD AIR NOSING SOUTHWARD INTO
THE AREA. MOISTURE ON THIS ISENTROPIC SURFACE CLEARS OUT BY MIDNIGHT
WITH A SUBSTANTIAL REDUCTION IN PRECIPITATION EXPECTED BY THIS TIME.

AFTER MIDNIGHT...SHALLOWER MOISTURE WILL REMAIN OVER THE AREA AS THE
ATMOSPHERE DRIES FROM THE TOP DOWN. BY 3 AM FRIDAY MORNING FORECAST
ISENTROPIC MOTION IS DOWNWARD THROUGHOUT THE ENTIRE MOIST LAYER...
WHICH USUALLY SPELLS THE END OF PRECIPITATION. HOWEVER AN IMPRESSIVE
300 MB JET STREAK OFF THE MID-ATLANTIC COAST WILL REMAIN FAVORABLY
ORIENTED TO SQUEEZE EVERY LITTLE BIT OF MOISTURE OUT OF THE
REMAINING CLOUD DECK. THE 00Z NAM IS QUITE A BIT MORE MOIST THAN THE
00Z GFS...AND 00Z SREF MEMBERS SHOW 30-50 PERCENT CHANCES FOR
LINGERING LIGHT PRECIPITATION AS SURFACE TEMPERATURES PLUNGE TO NEAR
FREEZING. FORECAST SOUNDINGS AT 09Z-12Z FRI REVEAL A HEALTHY SLUG OF
COLD AIR BELOW 3000 FEET AGL WHICH SHOULD BE SUFFICIENT TO FREEZE
FALLING HYDROMETERS INTO SLEET PELLETS. ANYTHING FALLING DURING
THAT TIME SHOULD TAKE THE FORM OF SLEET...OR PERHAPS RAIN WHERE
LOW-LEVEL TEMPERATURES ARE WARM ENOUGH TO REMELT PRECIPITATION.
FORECAST QPF AFTER 06Z IS QUITE LOW (.02" OR LESS) AND WITH VERY
WARM GROUND TEMPERATURES OVER THE PAST 48 HOURS IT APPEARS THIS
SHOULD BE NOT BE A SIGNIFICANT WINTER WEATHER EVENT.
-- End Changed Discussion --

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...BACK TO WINTER WEATHER FOR FRIDAY INTO
SATURDAY. TEMPS WILL START OUT BELOW FREEZING FRI MORNING IN
STRONG CAA BEHIND COLD FRONT. ALTHOUGH THE COLD FRONT WILL BE WELL
SOUTH...A BROAD MID TO UPPER TROUGH WILL REMAIN. THIS WILL PRODUCE SW
WINDS ALOFT WHICH WILL KEEP A WARMER FLOW ALOFT. ALTHOUGH
SOUNDINGS AND MOISTURE PROFILES SHOW THE COLUMN DRYING OUT...THERE
WILL BE ENOUGH MOISTURE BETWEEN 2-7K FT MAINLY ALONG THE COAST TO
ALLOW FOR SOME LINGERING PCP INTO THE MORNING HOURS. A PROMINENT
WARM NOSE WILL EXIST BETWEEN 4-10K FT WHICH LEAVES A FEW THOUSAND
FT OF BELOW FREEZING TEMPS BEFORE PCP REACHES THE GROUND.
THEREFORE LOOKS MORE LIKE POTENTIAL FOR SLEET...BUT THE LOWEST 2K
FT REMAINS DRY AND THERE APPEARS TO BE SOME SUBSIDENCE ALOFT BY
MID MORNING. THEREFORE DO NOT EXPECT MUCH IN THE WAY OF QPF.
ALSO...TEMPS ALONG THE SC COAST MAY NOT BE BELOW 0 C DURING FRI
MORNING AND OTHER PLACES WITH POTENTIAL FOR SLEET OR POSSIBLY FZG
RAIN SHOULD NOT SEE ANY ACCUMULATION ON MOST SURFACES BECAUSE THE
TEMPS WERE VERY WARM MOVING INTO THIS EVENT. PERHAPS THERE WILL BE
A BIT ON GRASSY OR ELEVATED SURFACES SUCH AS TREES, ETC...

THIS MOIST LAYER BECOMES SHALLOWER THROUGH THE DAY AND SHOULD END
UP WITH JUST A LAYER OF STRATUS BEFORE BREAKING UP TO STRATO CU
AND CLEARING OUT BY LATE FRI. TEMPS MAY STRUGGLE TO MAKE IT MUCH
PAST THE MID 30S ALONG THE COAST BUT INLAND AREAS SHOULD SEE SOME
BREAKS OF SUN BY AFTN GIVING A PUSH FOR WARMER TEMPS ONCE
SHORTWAVE MOVES OFF SHORE BY FRI EVENING DEEP DRY AND COLD AIR
WILL PRODUCE CLEAR SKIES AND COLD TEMPS FOR FRI NIGHT. ARCTIC HIGH
PRESSURE WILL SETTLE OVER THE SOUTHEAST OVER THE SOUTHEAST FRI
NIGHT INTO SATURDAY. 850 TEMPS BOTTOM OUT AROUND 1 TO 2 C
REMAINING THIS LOW FROM FRI MORNING THROUGH SAT MORNING. AIR MASS
WILL BEGIN TO MODIFY ON SATURDAY AND WITH MARCH SUNSHINE EXPECT
TEMPS TO REBOUND NICELY FROM THE 20S VERY EARLY SAT MORNING UP TO
THE 50S BY AFTN. WITH HIGH PRESSURE OVERHEAD SAT NIGHT WITH CLEAR
SKIES AND CALM WINDS...EXPECT TEMPS TO DROP DOWN INTO THE MID 30S
MOST PLACES.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...HIGH PRESSURE OVER THE SOUTHEAST ON
SUNDAY WILL SHIFT OFF SHORE SUN NIGHT INTO MONDAY. THEREFORE
SUNDAY WILL REMAIN DRY WITH SUNSHINE AND TEMPS WARMING INTO THE
60S MOST PLACES IN A WARMER RETURN FLOW. AS ONE HIGH PRESSURE
SYSTEM SHIFTS OFF SHORE ANOTHER AREA OF HIGH PRESSURE WILL BUILD
IN BEHIND IT AT THE SURFACE THROUGH MID WEEK. IN THE MID TO UPPER
LEVELS...THE CAROLINAS WILL REMAIN IN BETWEEN A VERY BROAD TROUGH
REACHING DOWN FROM THE GREAT LAKES AND A RIDGE TO OUR SOUTHEAST.
THIS WILL MAINTAIN A W-SW FLOW ALOFT WITH POTENTIAL FOR A FEW
SHORTWAVES TO PRODUCE SOME CLOUDS AND PCP MON THROUGH WED. WILL
KEEP A GOOD AMOUNT OF CLOUDS AND LOW END PCP THROUGH THE PERIOD.
TEMPS WILL BE CLOSER TO SEASONABLE VALUES.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...WITH THE EXCEPTION OF IFR/LIFR DUE TO SEA FOG AT KCRE
THROUGH THE MORNING HOURS...EXPECT VFR TO PREVAIL TODAY WITH GUSTY
SOUTHWEST WINDS AHEAD OF AN APPROACHING COLD FRONT WHICH WILL
PROPAGATE THROUGH THE AREA LATER TODAY. BEHIND THE
FRONT...CONDITIONS ARE THEN EXPECTED TO DETERIORATE TO MVFR/IFR
TONIGHT AND THROUGH THE OVERNIGHT HOURS DUE TO LOW CIGS...AREAS OF
FOG...AND RAINFALL.

WITH SOUTHWEST WINDS AOB 12 KTS WITH GUSTS ALREADY UP TO 20 KTS IN
SOME LOCATIONS...SEA FOG CONTINUES TO CREATE IFR/LIFR THIS MORNING
AT KCRE. CONDITIONS ARE EXPECTED TO IMPROVE LATER THIS
MORNING...WHICH WILL ALLOW FOR VFR TO PREVAIL AT ALL TAF SITES FOR
THE REST OF TODAY. HAVE KEPT IN POSSIBILITY OF LOW LEVEL WIND SHEAR
AROUND 30 TO 35 KTS FOR THE NEXT COUPLE OF HOURS.

LATER THIS AFTERNOON...THE COLD FRONT WILL PUSH THROUGH THE AREA
BRINGING A VEERING OF THE WINDS TO THE NORTH...WITH SUSTAINED WINDS
INCREASING TO AOB 20 KTS AND GUSTS UP TO NEAR 30 KTS POSSIBLE.
BEHIND THE FRONT ANTICIPATE MVFR/IFR WITH RAIN...LOW CIGS...AND
AREAS OF FOG...TONIGHT THROUGH THE OVERNIGHT HOURS. TOWARDS
MORNING...PRECIPITATION WILL TAPER OFF WEST TO EAST...BUT WILL NOTE
THAT BEFORE PRECIPITATION MOVES OUT OF THE COASTAL AREAS THERE IS A
POTENTIAL FOR SOME ICE PELLETS TOWARDS THE END OF THE TAF PERIOD.
HOWEVER...GIVEN LOWER CONFIDENCE HAVE NOT INTRODUCED IN GOING
FORECAST ATTM.

EXTENDED OUTLOOK...IFR CONDITIONS POSSIBLY INTO FRIDAY ALONG THE
COAST. OTHERWISE EXPECT VFR.

&&

.MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM THURSDAY...THE SEA FOG HAS EXPANDED ACROSS THE
MAJORITY OF THE ILM COASTAL WATERS. AND IT HAS REACHED DENSE
THRESHOLDS SPECIFICALLY FOR THE COASTAL WATERS...RESULTING IN A
MWW BEING ISSUED FOR DENSE FOG CONDITIONS...IE. LESS THAN 1 NM.

THE WINDS ACROSS THE LOCAL WATERS WILL SLOWLY VEER TODAY...FROM
SSW TO SW THIS MORNING...AND FROM SW TO WSW THIS AFTERNOON.
COMMON SPEEDS WILL RANGE FROM 15 TO 20 KT WITH A FEW GUSTS UP TO
25 KT. THIS VEERING IN THE WIND FIELD WILL EVENTUALLY CEASE THE
ADVECTION OF THE SEA FOG ONSHORE. SIGNIFICANT SEAS WILL BECOME
PRIMARILY WIND DRIVEN WITH PERIODS BETWEEN 5 TO 7 SECONDS.

PREVIOUS DISCUSSION............................................
AS OF 630 AM THURSDAY...STEADY SOUTHWEST WINDS CONTINUE TO BRING
SUBTROPICAL MOISTURE NORTH ACROSS THE AREA. WHERE THIS MOISTURE
ENCOUNTERS THE VERY CHILLY OCEAN WATER WE HAVE A LONG-LIVED DENSE
SEA FOG EVENT ONGOING. AIRPORT WEATHER OBSERVATIONS FROM NORTH
MYRTLE BEACH & SOUTHPORT CONFIRM THE FOG IS STILL VERY DENSE.

VERY LITTLE SHOULD CHANGE IN THE SYNOPTIC WIND SETUP THIS MORNING
INTO THE EARLY AFTERNOON...UNTIL A POWERFUL COLD FRONT NOW TAKING
SHAPE ACROSS SOUTHERN VIRGINIA SINKS SOUTHWARD INTO THE AREA. THIS
FRONT WILL BRING AN INSTANTANEOUS SHIFT TO NORTH WINDS DURING THE
LATE AFTERNOON HOURS...WITH WIND SPEEDS INCREASING TO 25-30 KNOTS
TONIGHT. GUSTS TO GALE FORCE SHOULD OCCUR DURING THE PERIOD OF
STRONGEST COLD AIR ADVECTION LATE THIS EVENING AND OVERNIGHT...AND
WE HAVE TURNED THE GALE WATCH INTO A GALE WARNING BEGINNING AT 9 PM
THIS EVENING.

SEAS CURRENTLY 3-5 FEET ARE NEARLY STEADY-STATE WITH THE SOUTHWEST
WINDS...BUT SHOULD INCREASE TO 6-9 FEET OVERNIGHT...HIGHEST EAST OF
CAPE FEAR AND EAST OF WINYAH BAY WHERE NORTH WINDS WILL HAVE THE
LONGEST EFFECTIVE FETCH TO WORK WITH.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM THURSDAY...EXPECT STRONG NORTH WINDS UP TO 20-30 KTS
FRIDAY MORNING IN A TIGHTENED GRADIENT FLOW AND COLD SURGE. A GALE
WARNING WILL LAST INTO FRI MORNING. HIGH PRESSURE WILL BUILD OVER
THE SOUTHEAST LATE FRIDAY THROUGH SATURDAY...WITH NORTH WINDS
DIMINISHING AND BECOMING MORE VARIABLE. SEAS UP TO 5-9 FT
EARLY FRIDAY...WILL FALL THROUGH THE DAY...BECOMING 2-4 FT BY FRI
NIGHT. WINDS AND SEAS WILL CONTINUE TO FALL THROUGH SATURDAY WITH
LESS THAN 3 FT SEAS BY SAT EVE INTO SUN.

LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 330 AM THURSDAY...HIGH PRESSURE OVER THE SOUTHEAST WILL
SHIFT OFF SHORE BY SUN NIGHT AS A WAVE OF LOW PRESSURE RIDES UP
FROM THE SOUTHWEST INTO MONDAY. EXPECT VERY LIGHT AND VARIABLE
WINDS ON SUNDAY WITH SEAS LESS THAN 3 FT. WINDS WILL INCREASE
UP TO 10 TO 15 KTS OUT OF THE N TO NE AS HIGH PRESSURE BUILDS
BACK IN MON NIGHT INTO TUES. SEAS WILL BE BACK UP TO 2 TO 4 FT BY
MON NIGHT INTO TUES.
-- End Changed Discussion --

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
SC...DENSE FOG ADVISORY UNTIL 6 PM EST THIS EVENING FOR SCZ054-056.

NC...DENSE FOG ADVISORY UNTIL 6 PM EST THIS EVENING FOR NCZ106-108-
     110.

MARINE...DENSE FOG ADVISORY UNTIL 6 PM EST THIS EVENING FOR AMZ250-252-
     254-256.

     GALE WARNING FROM 9 PM THIS EVENING TO 10 AM EST FRIDAY FOR
     AMZ250-252-254-256.
-- End Changed Discussion --

&&

$$
SYNOPSIS...RGZ
NEAR TERM...DCH/TRA
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...SGL