198 
FXUS62 KILM 120739
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
339 AM EDT WED MAR 12 2014

.SYNOPSIS...
SPRING LIKE WARMTH WILL CONTINUE TODAY AHEAD OF A STRONG COLD
FRONT WHICH WILL CROSS TONIGHT. MUCH COLDER TEMPERATURES EXPECTED
THURSDAY AND FRIDAY AS CANADIAN HIGH PRESSURE BUILDS INTO THE
AREA. A GRADUAL WARMING TREND TO SEASONABLE TEMPERATURES WILL
OCCUR OVER THE WEEKEND. A LOW PRESSURE SYSTEM MAY BRING UNSETTLED
WEATHER LATE IN THE WEEKEND AND ON MONDAY. COOL HIGH PRESSURE
WILL FOLLOW FOR TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 PM TUESDAY...NO SIGNIFICANT CHANGES WITH THIS LATE 
EVENING UPDATE. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS...

LOW PRESSURE ALREADY BELOW 1000 MB ACROSS MISSOURI WILL REMAIN WELL 
NORTH OF THE CAROLINAS AS IT MOVES EAST OVERNIGHT INTO WEDNESDAY. A 
COLD FRONT EXTENDING SOUTH THROUGH TEXAS WILL MOVE INTO THE AREA 
TOMORROW. UNTIL THEN...WE ARE ENJOYING THE LAST DAY OF DRY MILD 
WEATHER IN THE WARM SECTOR BEFORE GULF MOISTURE ARRIVES. AN UPPER 
LEVEL DISTURBANCE OVER THE CENTRAL GULF COAST WILL DE-AMPLIFY AS IT 
MOVES EAST-NORTHEASTWARD TOWARD THE CAROLINAS. THE 15Z SREF MEAN 
LOOKED SIMILAR TO THE 18Z NAM AND GFS WITH REGARDS TO THE ONSET OF 
PRECIPITATION POTENTIAL OVERNIGHT. BEFORE DAYBREAK ODDS ARE LESS 
THAN 50% THAT ANY OF OUR FORECAST AREA WILL SEE RAINFALL... HOWEVER 
MY HIGHEST FORECAST POPS (30-40 PERCENT) ARE IN THE 
FLORENCE-DARLINGTON-KINGSTREE AREA JUST BEFORE SUNRISE. AT THE COAST 
POPS RANGE FROM 20 PERCENT ALONG THE GRAND STRAND TO LESS THAN 10 
PERCENT IN WILMINGTON.

CIRRUS-LEVEL CLOUD COVER SHOULD SLOWLY INCREASE LATE THIS EVENING 
AND SHOULD DESCEND INTO A MID DECK AFTER MIDNIGHT AHEAD OF THE 
INCOMING DISTURBANCE. A RATHER IMPRESSIVE LOW LEVEL JET WITH 1000 
FOOT WIND SPEEDS 25-30 KNOTS SHOULD DEVELOP SHORTLY WITH ENOUGH 
INDUCED BOUNDARY LAYER TURBULENCE TO KEEP TEMPERATURES FROM DROPPING 
TOO FAR THIS EVENING. THE ADDITION OF THICKENING CLOUD COVER AFTER 
MIDNIGHT SHOULD PRODUCE A NEARLY STEADY TEMPERATURE CURVE THEN. FEW 
ADJUSTMENTS HAVE BEEN MADE TO FORECAST LOWS WHICH RANGE FROM 55-58 
ACROSS THE AREA.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...HARSH RETURN TO REALITY THURSDAY AS STRONG 
CAA BEHIND AN ARCTIC FRONT DRIVES TEMPS TO WELL BELOW NORMAL FOR MID 
MARCH...WITH HIGHS ABOUT 30 DEGREES COOLER THAN THE PAST FEW DAYS! 
EVEN THE INCREASINGLY STRONG SUN ANGLE WILL DO LITTLE TO HELP WARM 
THINGS UP THURSDAY...AND EXPECT HIGHS TO REMAIN SUB-50 ACROSS NC 
THURSDAY...WITH SOME LOW 50S POSSIBLE IN THE PEE DEE REGION AND 
TOWARDS THE SANTEE RIVER. IN ADDITION...GUSTY NW WINDS THROUGH THE 
DAY WILL KEEP APPARENT TEMPS ONLY IN THE MID/UPR 40S...SO JUST A 
BRUTALLY COLD MARCH DAY...ESPECIALLY AFTER THE WARMTH OF THE PAST 
WEEK.

AS ARCTIC HIGH MOVES OVERHEAD THURSDAY NIGHT...TEMPS WILL PLUMMET 
AFTER DARK...AND A WIDESPREAD SUB-FREEZING EVENT IS LIKELY. WHILE 
THE OFFICIAL LOCAL GROWING SEASON HAS NOT BEGUN AS OF YET...EARLY 
AND SENSITIVE PLANTS WILL NEED TO BE PROTECTED THURSDAY NIGHT AS 
TEMPS FALL INTO THE MID/UPR 20S...WITH MANY HOURS OF SUB-32 TEMPS 
EXPECTED.

SURFACE HIGH SHIFTS OFFSHORE DURING FRIDAY...IN CONJUNCTION WITH 
MID-LEVEL THICKNESS INCREASE. THIS WILL DRIVE TEMPS FRIDAY 
CONSIDERABLY HIGHER THAN THOSE OF THURSDAY...BUT STILL REMAIN A 
SOLID 6-10 DEGREES BELOW NORMAL...WITH UPPER 50S COMMON ACROSS THE 
AREA...LOWER 60S IN THE FAR SOUTHERN ZONES. A COASTAL TROUGH WILL 
TRY TO DEVELOP ON THE WESTERN PERIPHERY OF THIS HIGH PRESSURE LATE 
IN THE PERIOD. GFS IS MOST AGGRESSIVE WITH SKY COVER/POP FRIDAY 
NIGHT...AND WILL LEAN ON THE NAM/ECMWF WHICH ARE WEAKER AND MORE 
REASONABLE IN RELATIVELY FAST MID-LEVEL FLOW AND WEAK MOIST 
ADVECTION. MINS FRIDAY NIGHT WILL FALL TO SEASONABLE LEVELS...LOW 
40S MOST PLACES.


&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 AM WEDNESDAY...SOME UNCERTAINTY FOR THE WEEKEND...BEFORE
A PERIOD OF UNSETTLED WEATHER DEVELOPS EARLY NEXT WEEK.

ZONAL FLOW THROUGH THE WKND WILL HELP TEMPS RISE TO SEASONABLE 
LEVELS AHEAD OF A WEAK COLD FRONT DRIVEN BY A MID-LEVEL IMPULSE 
EARLY SUNDAY. GUIDANCE DIFFERS AS TO HOW MUCH MOISTURE WILL BE 
ACCOMPANIED BY THIS FEATURE...WITH THE GFS SHOWING DECENT RAIN 
CHANCES WHILE THE ECMWF IS PRIMARILY DRY. AS NOTED BY PREVIOUS 
FORECASTER...DEEP BAROCLINIC INSTABILITY ALL THE WAY TO THE GULF 
COAST WOULD SUPPORT SOME FORCING AND PRECIP WITH THIS FEATURE...BUT 
OVERALL MOIST ADVECTION IS LIMITED ON THE ZONAL FLOW. STILL...SCHC 
POP IS INHERITED AND WILL REMAIN LATE SAT NIGHT INTO SUNDAY WITH 
LITTLE QPF.

A MORE SIGNIFICANT SYSTEM WILL EMERGE OUT OF THE GULF AS A STRONGER 
SOUTHERN STREAM IMPULSE DIVES INTO THE SOUTHEAST SPAWNING 
CYCLOGENESIS WHICH WILL THEN TRAVERSE NEAR OR OVER THE AREA INTO 
MONDAY. MUCH BETTER PRECIP CHANCES ASSOCIATED WITH THIS...AND THE 
SUN NIGHT INTO MONDAY TIMEFRAME COULD BE QUITE WET. COOL HIGH 
PRESSURE THEN BUILDS INTO THE AREA BEHIND THIS FEATURE...BUT TEMPS 
WILL FALL ONLY TO SEASONABLE OR SLIGHTLY BELOW FOR EARLY NEXT WEEK.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...EXPECT INITIAL VFR EXCEPT MVFR AT THE COASTAL TERMS
DUE TO SEA FOG...THROUGH MUCH OF THE PRE-DAWN WED HOURS. CONDITIONS
WILL GRADUALLY DETERIORATE TO MVFR/POSSIBLE IFR AT ALL LOCATIONS
TOWARD DAYBREAK WED DUE TO LOW CIGS AND RAINFALL IN ASSOCIATION
WITH AN UPPER LEVEL S/W TROF AND AN APPROACHING SFC COLD FRONT.

INCREASING HIGH CLOUDS AND SOUTHWEST WINDS AOB 8 KTS WILL PREVAIL 
THROUGH THE PRE-DAWN WED HOURS...WITH INCREASING MID-LEVEL CLOUDS
AS WELL. A FEW MODELS ARE SUGGESTING THE POSSIBILITY OF BRIEF FOG
DEVELOPMENT...BUT GIVEN WIND PROFILE AND INCREASING CLOUDS...DO
NOT ANTICIPATE DEVELOPMENT. HOWEVER...SEA FOG IS A POSSIBILITY AT
THE COASTAL TERMS THIS AM. AS WINDS VEER EVER SO SLIGHTLY TO THE
SW FROM SSW...THE SEA FOG WILL REMAIN OVER THE ATL WATERS. 
AFTER DAYBREAK...CONDITIONS THRU THE MID-MORNING HOURS WILL
CONTINUE TO DETERIORATE TO MVFR/IFR AS LOW CIGS INFILTRATE INTO
THE AREA ALONG WITH INCREASING RAINFALL CHANCES FROM SOUTHWEST TO
NORTHEAST ACROSS THE AREA. COULD NOT RULE OUT AN ISOLATED TSRA
IN THE AFTERNOON HOURS...BUT ANTICIPATE OVERALL TSTORMS CHANCES
TO REMAIN NORTH OF THE AREA. WINDS WILL INCREASE THROUGHOUT THE
DAY AS WELL...WITH SOUTHWEST WINDS NEAR 15-20 KTS SUSTAINED AND
GUSTS NEAR 30 KTS POSSIBLE. INTO THE LATE EVENING HOURS...RAIN
CHANCES WILL TAPER OFF AND THE COLD FRONT WILL PUSH THROUGH THE
AREA. INCREASED WINDS WILL PERSIST AND VEER TO THE NORTHWEST JUST
BY THE END OF THE TAF PERIOD WITH THE FRONTAL PASSAGE.

EXTENDED OUTLOOK...VFR EXPECTED THURSDAY AND FRIDAY. CHANCE OF 
SHOWERS ON SATURDAY. VFR SUNDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM TUESDAY...NO SIGNIFICANT CHANGES WITH THIS LATE 
EVENING UPDATE. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS...

QUITE A SEABREEZE DEVELOPED THIS AFTERNOON AS INLAND TEMPERATURES 
SOARED TO AROUND 80 DEGREES WHILE MARINE AIR TEMPERATURES MADE IT NO 
HIGHER THAN THE UPPER 50S. THIS 20-25 DEGREE TEMPERATURE GRADIENT 
FUELED WIND GUSTS TO NEAR 20 KNOTS AT THE BEACHES. THESE WINDS ARE 
BEGINNING TO SUBSIDE AS INLAND TEMPERATURES COOL...BUT A MODEST 
PRESSURE GRADIENT AHEAD OF TOMORROW'S INCOMING COLD FRONT SHOULD 
MAINTAIN WINDS IN THE 12-15 KNOT RANGE THROUGH MOST OF THE NIGHT. 
BESIDES INCREASING FORECAST NEARSHORE WIND SPEEDS IN THE 0-3 HOUR 
RANGE...THE BIGGEST CHANGE TO THE FORECAST WAS TO REDUCE FORECAST 
SEA HEIGHTS LATER TONIGHT AS SEAS SHOULD NOT BUILD APPRECIABLY UNTIL 
WIND SPEEDS INCREASE LATE TOMORROW MORNING AHEAD OF THE COLD FRONT. 
CURRENT OBSERVATIONS SHOW 2-3 FOOT SEAS.

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...ARCTIC FRONT OFFSHORE TO START THE PERIOD 
LEAVES STRONG NW WINDS IN ITS WAKE...AND A SMALL CRAFT ADVISORY WILL 
LIKELY BE ONGOING THURSDAY MORNING. WINDS WILL BE 20-30 KTS THROUGH 
THE DAYLIGHT HOURS OF THURSDAY...EASING THURSDAY NIGHT TO AROUND 10 
KTS WHILE BECOMING MORE NORTHERLY BY FRIDAY MORNING. SEAS OF 4-7 FT 
THE FIRST HALF THURSDAY WILL DROP QUICKLY THURSDAY NIGHT AS THE 
WINDS EASE WHILE STILL MAINTAINING AN OFFSHORE COMPONENT...WITH WAVE 
HEIGHTS BECOMING 1-3 FT FRIDAY MORNING. HIGH PRESSURE SHIFTS 
OFFSHORE ON FRIDAY...SO WINDS BECOME LIGHT AND VARIABLE MUCH OF THE 
DAY...EVENTUALLY TAKING ON A PREDOMINANT SW DIRECTION AROUND 10 KTS 
FRIDAY NIGHT. SEAS REMAIN LOW-AMPLITUDE HOWEVER...PERSISTING AT 1-3 
FT INTO THE WKND.

LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE OFFSHORE SATURDAY LEAVES 
10-15 KTS SW WINDS ACROSS THE WATERS ON RETURN FLOW. THESE WINDS 
WILL PERSIST INTO SUNDAY MORNING...BEFORE A WEAK COLD FRONT CROSSES 
THE WATERS AND TURNS THE WINDS TO THE NW...THEN NE...ON SUNDAY BUT 
AT SPEEDS OF ONLY 10 KTS OR LESS. SEAS WILL RISE BRIEFLY TO 3-5 FT 
DURING THE STRONGEST SW WINDS SATURDAY AFTN...BUT WILL OTHERWISE BE 
2-4 FT THROUGH THE PERIOD.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 6 PM EDT THIS 
     EVENING FOR AMZ250-252-254-256.

     GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EDT THURSDAY FOR 
     AMZ250-252-254-256.

&&

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