556 
FXUS62 KILM 190325
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1125 PM EDT MON MAR 18 2013

.SYNOPSIS...
SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS WILL MOVE ACROSS
THE AREA TONIGHT AHEAD OF A STRONG COLD FRONT. THIS FRONT WILL
CROSS EARLY TUESDAY...WITH HIGH PRESSURE BUILDING IN BEHIND IT
BRINGING MUCH COOLER TEMPERATURES THROUGH THE END OF THE WEEK. A
STORM SYSTEM WILL BRING ANOTHER CHANCE FOR WET WEATHER INTO THE
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 1100 PM MONDAY...COOL AIR HOLDING FIRM AWAY FROM THE COAST.
MID-LEVEL S/W TROF OVER SOUTHWEST SC...IS PROGGED TO LIFT NE
OVERNIGHT. PCPN ASSOCIATED WITH THIS UPPER FEATURE TO CURRENTLY 
PUSH ACROSS THE FA LATE THIS EVENING AND DURING THE PRE-DAWN HOURS
OF TUE. MUCH OF THE ACTIVITY WILL BE EAST OF THE FA BY 4 AM. WITH
THE WEDGE STILL IN PLACE...THE PCPN AS IT REACHES THE FA WILL
MAINLY BE LIGHT TO MODERATE RAIN SHOWERS. AS THIS UPPER FEATURE
MOVES ACROSS THE FA OVERNIGHT...ISOLATED AND ELEVATED CONVECTION
WILL OCCUR...WITH ANY THUNDER MAINLY OVER THE ILM SC COUNTIES AND
FURTHER SOUTH. SFC BASED INSTABILITY LACKING ACROSS THE MAJORITY
OF THE ILM CWA. ITS WHERE SFC DEWPOINTS IN THE 60 OR HIGHER RANGE
DO YOU FIND THE BETTER INSTABILITY TO FUEL CONVECTION...AND THIS
WILL NOT BE THE CASE FOR THE ILM CWA OVERNIGHT. THIS WEDGE WILL
FINALLY ERODE FROM THE SOUTH AND EAST AS THIS UPPER FEATURE LIFTS
NORTH OF THE ILM CWA OVERNIGHT. THE ACTUAL SFC COLD FRONT IS
PROGGED TO LAG WELL BEHIND THIS AREA OF PCPN. MODELS BRING THE
COLD FRONT TO THE NW DOORSTEPS OF THE ILM CWA BY DAYBREAK...WITH A
BAND OF PCPN JUST AHEAD OF IT.

LOWS TO OCCUR AROUND MIDNIGHT TONIGHT WITH A STEADY OR SLOW CLIMB
THERE-AFTER. HAVE ADJUSTED POPS FOR LATE THIS EVENING AND
OVERNIGHT...WITH EXTRAPOLATION FROM THE CURRENT PCPN COVERAGE AS 
OBSERVED WITH RADAR MOSAICS. 

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...ONE MORE WARM DAY TUESDAY BEFORE A STRONG COLD 
FRONT CROSSES BY EARLY AFTN...BRINGING MUCH COOLER TEMPERATURES ON 
WEDNESDAY.

COLD FRONT WILL BE ALONG THE WESTERN EDGE OF THE CWA AT THE START OF 
THE PERIOD. WHILE THE PRE-FRONTAL ENVIRONMENT WILL BE CHARACTERIZED 
BY HIGH PWAT AIR AND DEEP W/SW FLOW...OVERALL PRECIP CHANCES STILL 
LOOK RATHER SMALL THANKS TO LACK OF ANY SIGNIFICANT FORCING. WILL 
CONTINUE LOW-CHC POP ENDING FROM WEST-TO-EAST DURING THE LATE 
MORNING. TEMPS WILL START WARM...AND WILL CONTINUE TO WARM THROUGH 
THE EARLY AFTN WITH HIGHS REACHING TO NEAR 70 MOST LOCATIONS. IT 
WILL BE AN INTERESTING DIURNAL CURVE HOWEVER...WITH TEMPS LIKELY 
FALLING A BIT THROUGH THE LATE MORNING BEFORE RISING LATER IN THE 
DAY AS THE SUN BREAKS OUT SINCE MID-LEVEL CAA LAGS BEHIND THE FRONT 
UNTIL TUESDAY NIGHT. AS THE CAA INCREASES LATE TUESDAY...IT WILL 
HELP MIN TEMPS FALL INTO THE UPPER 30S INLAND...LOW 40S AT THE 
COAST...MAKING FOR A SIGNIFICANT DIURNAL TEMP RANGE TUESDAY.

BRIEF RIDGE OF HIGH PRESSURE MOVES ACROSS THE REGION WEDNESDAY...BUT 
COOL NORTH WINDS WILL HOLD MAX TEMPS IN CHECK. EXPECT HIGHS TO 
REMAIN BELOW NORMAL FOR MID-MARCH...RISING ONLY INTO THE UPPER 
50S/LOW 60S. A SECONDARY SURGE OF COOL AIR /WEAK BUT DRY COLD FRONT/ 
MOVES SE THROUGH THE CAROLINAS WED NIGHT. THIS WILL CREATE ENHANCED 
CAA AND TEMPS WILL PLUMMET WED NIGHT. WILL LEAN ON THE COOLER MET 
NUMBERS WHICH SUPPORTS LOW 30S MOST SPOTS...AND SOME FROST IS 
POSSIBLE BY THURSDAY MORNING.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...MEDIUM RANGE GUIDANCE...AT LEAST THE
PREFERENCE FROM WPC CONTINUES TO PAINT A RATHER UNSETTLED AND COOL
SCENARIO FOR THE EASTERN CAROLINAS AND THE SOUTHEAST FOR THAT
MATTER.

AN ARCTIC AIR MASS WILL BE IN PLACE AS SUBTLE SHORTWAVES WILL DIVE 
INTO THE CENTRAL PLAINS WITH A STRONG WEST TO EAST BAROCLINIC ZONE 
DEVELOPING ALONG THE GULF COAST. OUR AREA WILL BE ON THE NORTHERN 
FRINGE OF THE MOISTURE THEREFORE POPS REMAIN IN THE CHANCE RANGE AND 
CONFIDENCE A BIT LOWER THAN USUAL. WITH WPC LEANING TOWARD THE 
ECMWF...MOSTLY THE HIGHER RESOLUTION MODEL FROM SUNDAY...A 
PROLONGED PERIOD OF LOW CLOUDS...INTERVALS OF LIGHT RAIN/DRIZZLE AND 
COOL TEMPERATURES IS IN ORDER FROM FRIDAY THROUGH MONDAY. THE 
STRONGEST...RELATIVELY SPEAKING WAVE RIDES BY SATURDAY AND HENCE 
THATS WHERE THE HIGHEST POPS ARE PAINTED. OVERALL QPF LOOKS TO BE 
LIGHT. HOWEVER INTERESTING TO NOTE THE LATEST OPERATIONAL GFS SHOWS 
A MORE SIGNIFICANT CLOSED SYSTEM ROTATING ACROSS THE CAROLINAS SO AT 
LEAST SOMETHING TO WATCH FOR. 

AS FOR TEMPERATURES...STILL EXPECT WITH THE COOL DIFFUSE WEDGE AND 
PERSISTENT MOISTURE...OVERALL READINGS WILL BE WELL BELOW NORMAL. I 
DID TAKE THE LIBERTY TO CLOSE THE DIURNAL RANGES A BIT CITING ALL 
THE MOISTURE.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...A NEAR-STATIONARY FRONTAL BOUNDARY REMAINS JUST SOUTH
OF OUR CWA...AND SATELLITE IMAGERY SHOWS WIDESPREAD VFR/MVFR CIGS
ACROSS THE AREA. RADAR MOSAIC INDICATES SCT SHRA/TS HAVE MOVED
OVER THE WESTERN CAROLINAS AHEAD OF AN APPROACHING COLD FRONT.
LOCALIZED AREAS OF IFR ARE BEING REPORTED ALONG THE S.C. COAST.

SOME SCT -SHRA ARE POSSIBLE OVERNIGHT...BEGINNING AT KFLO/KLBT 
AROUND 04Z. HAVE HIGHER CONFIDENCE FOR IFR CIGS IN OUR CWA AFTER 
06Z...BUT INCLUDED TEMPO IFR FOR THE INLAND TERMS BEGINNING AROUND 
MIDNIGHT. COLD FROPA WILL OCCUR TUESDAY MORNING...LIKELY JUST AFTER 
12Z INLAND AND AROUND 14Z ALONG THE COAST. SOUTHEAST WINDS AOB 8 KTS 
TONIGHT WILL BECOME SOUTHWEST EARLY TUESDAY AND WEST-NORTHWEST 
AROUND 10 KTS FOLLOWING FROPA. SKIES WILL CLEAR OUT BY MIDDAY...AND 
THEN VFR SHOULD PREVAIL THROUGH 00Z WEDNESDAY.  

EXTENDED OUTLOOK...CHANCE OF RAIN LATE FRIDAY INTO SATURDAY... 
OTHERWISE VFR CONDITIONS SHOULD PREVAIL THROUGH THE EXTENDED PERIOD.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 PM MONDAY...THE COASTAL FRONT OR WHATS LEFT OF IT...
WILL LIFT NORTH OF THE AREA WATERS LATER THIS EVENING AND
OVERNIGHT. LOOKING AT SE FLOW BECOMING S TO SW AFTER MIDNIGHT.
41013 FRYING PAN SHOALS HAS BEEN SOUTHERLY FOR THE MAJORITY OF
THIS EVENING. CLOSER TO THE COAST...E TO SE WINDS STILL BEING
REPORTED. SPEEDS AROUND 10 KT THIS EVENING WILL INCREASE TO A
SOLID 15 KT AFTER MIDNIGHT WITH GUSTS UP TO 20 KT. A TIGHTENED SFC
PG AFTER THE LIFTING/PASSAGE OF THE SO-CALLED WARM FRONT WILL
PRODUCE THESE HIER SPEEDS. WIND DRIVEN SHORT PERIOD WAVES WILL
GOVERN THE SIGNIFICANT SEAS. LOOKING AT TWO TO 4 FT THROUGH LATE
THIS EVENING... INCREASING TO 3 TO 5 FT OVERNIGHT WITH AVERAGE
PERIODS 5 TO 6 SECONDS. A BORDERLINE SCEC REMAINS POSSIBLE LATE
TONIGHT INTO DAYLIGHT TUE...AND WILL CONTINUE TO MONITOR.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...WINDS OF 10-15 KTS WILL BE PERSISTENT ON 
TUESDAY...BUT FROM VARYING DIRECTIONS AS A COLD FRONT CROSSES THE 
WATERS. PRE-FRONTAL REGIME TUESDAY MORNING LEAVES 10-15 KTS SW WINDS 
AND SEAS OF 2-4 FT WITH ISOLATED 5 FTERS...WITH A SW WIND WAVE 
DOMINANT IN THE SPECTRUM. FRONT CROSSES FROM WEST TO EAST...TURNING 
WINDS TO THE NW TUESDAY AFTN...THEN VEERING SLOWLY TO THE NORTH BY 
WED MORNING. A PERIOD OF CONFUSED SEAS IS EXPECTED WITH THE 
FROPA...BUT EVENTUALLY A NORTHERLY WIND WAVE WILL BECOMING THE MAIN 
WAVE GROUP...WITH 2-4 FT SEAS PERSISTING. NORTH WINDS WEAKEN AND 
BECOME VARIABLE WEDNESDAY THANKS TO A RIDGE OF HIGH PRESSURE MOVING 
OVER THE WATERS...ALLOWING SEAS TO FALL TO 1-2 FT. LATE WED NIGHT A 
SURGE OF COLD AIR MOVES ACROSS THE AREA...TURNING WINDS BACK TO THE 
NW AT 10-15 KTS WITH SEAS REBUILDING TO 2-4 FT.

LONG TERM /THURSDAY THROUGH SATURDAY/... 
AS OF 300 PM MONDAY...FAIRLY POTENT NORTHWEST FLOW WILL BE IN
PLACE INITIALLY AS AN ARCTIC AIR MASS MOVES IN. EXPECT A RANGE OF
15-20 KNOTS. FOR FRIDAY AND SATURDAY...PRESSURE PATTERN WEAKENS
CONSIDERABLY AS A COLD AIR WEDGE DEVELOPS AS WELL AS UNSETTLED
CONDITIONS. THE WEDGE STRENGTHENS SOMEWHAT SATURDAY WITH WINDS
INCREASING TO 15-20 KNOTS ONCE AGAIN. SEAS WILL GENERALLY FOLLOW
THE WIND FIELDS WITH CHOPPY HIGHER VALUES THURSDAY...MAINLY
OFFSHORE THEN BENIGN FRIDAY INCREASING ONCE AGAIN FOR SATURDAY.

&&

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

&&

$$
SYNOPSIS...JDW
NEAR TERM...DCH/MBB
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...BJR