000 
FXUS62 KILM 161853
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
253 PM EDT THU JUL 16 2009

.SYNOPSIS...
SHOWERS AND STORMS WILL INCREASE IN COVERAGE FRIDAY AND SATURDAY AS 
A WARM AND HUMID SOUTHWESTERLY FLOW CONTINUES AHEAD OF AN
APPROACHING COLD FRONT. THIS COLD FRONT WILL STALL NEAR THE
CAROLINA COAST SATURDAY NIGHT...THEN REMAIN THERE AS IT SLOWLY
DISSIPATES THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...CONVECTION FLARING UP ALONG PIEDMONT TROUGH AS 
IT DEEPENS THIS AFTERNOON. THESE SHWRS/TSTMS WERE MOVING TOWARD THE 
EAST-NORTHEAST BUT AS STEERING FLOW BECOMES MORE WESTERLY AS THE DAY 
PROGRESSES...EXPECT THIS ACTIVITY TO MOVE EAST AND BECOME MORE
WIDESPREAD ACROSS CWA THROUGH LATE THIS AFTERNOON INTO THIS
EVENING. SHORTWAVE MOVING FROM GA INTO THE CAROLINAS THIS AFTN
WILL TRACK AND OFF THE COAST THROUGH THIS EVENING PROVIDING SOME
ENHANCEMENT TO THIS ACTIVITY. A FEW OF THE STORMS MAY BECOME
SEVERE WITH ISOLATED DAMAGING WIND A POSSIBILITY. KEPT MENTION OF
POPS THROUGH THIS EVENING...BUT EXPECT ACTIVITY TO TAPER OFF AS
DAYTIME HEATING CUTS OFF AND SHORTWAVE MOVES OFF SHORE. THEREFORE
ONLY LEFT SLIGHT CHC...MAINLY ALONG THE COAST HEADING INTO THE
MORNING. CLOUDS WILL CONTINUE TO SPREAD ACROSS THE AREA SO DO NOT
EXPECT TEMPS TO RISE MUCH MORE THIS AFTERNOON AND WITH DEW POINTS
UP IN THE 70S THE MIN TEMPS OVERNIGHT SHOULD ONLY DROP TO THE LOW
TO MID 70S. CLOUDS AND LIGHT WINDS WILL ALSO HELP TO KEEP TEMPS UP
THROUGH THE EVENING.

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...UNSETTLED CONDITIONS FRI WITH DEEP SOUTHWEST 
FLOW AHEAD OF COLD FRONT AND DEVELOPING 5H TROF. SHORTWAVE TROF 
MOVING OVER THE AREA FRI AFTERNOON MIGHT ENHANCE ONGOING
CONVECTION...BUT TIMING AND STRENGTH OF THE FEATURE REMAIN IN
QUESTION. BOTH THE 00Z GFS...AND TO A LESSER DEGREE...THE 00Z WRF
ARE HAVING ISSUES WITH FEEDBACK.

COLD FRONT REMAINS WELL WEST OF THE AREA FRI NIGHT AND SAT AS 5H 
TROF DIGS SOUTH THROUGH THE TN VALLEY. CONTINUED DEEP SOUTHWEST FLOW 
WILL KEEP PRECIPITABLE WATER VALUES ABOVE TWO INCHES THROUGH SAT
NIGHT. SHORTWAVES MOVING ACROSS THE AREA WILL ENHANCE LOW LEVEL
INSTABILITY AND PRECIP CHANCES. BEST CHANCE WILL BE SAT AFTERNOON
ALONG THE SEA BREEZE AND PIEDMONT TROF...THOUGH ONCE INITIAL
STORMS DEVELOP OUTFLOW BOUNDARIES WILL CAUSE COVERAGE TO INCREASE.

COLD FRONT MAY OR MAY NOT PUSH OFFSHORE LATE SAT NIGHT...BUT WILL
AT LEAST MOVE INTO THE AREA. FORECAST SOUNDINGS SHOW A LOT OF MID
LEVEL DRY AIR MOVING IN...WITH PRECIPITABLE WATERS DROPPING TO
NEAR 1 INCH BY THE END OF THE PERIOD.

HIGHS WILL BE NEAR CLIMO ON FRI WITH INCREASED CLOUD COVER AND 
PRECIP CHANCES KEEPING TEMPERATURES NEAR TO SLIGHTLY BELOW CLIMO ON 
SAT. CLOUD COVER AND LOW LEVEL MOISTURE OVERNIGHT WILL KEEP LOWS 
ABOVE CLIMO...THOUGH SAT NIGHT TEMPERATURES MAY BE A LITTLE CLOSER 
TO CLIMO DEPENDING ON WHERE THE FRONT ENDS UP.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...STILL A RATHER LOW CONFIDENCE FORECAST AS A 
LOT DEPENDS ON THE FATE OF THE COLD FRONT.  CURRENT THINKING IS THAT 
IT WILL STALL NEAR THE COAST ON SUNDAY AND LINGER THERE THRU THE 
PERIOD.  DEEP SW FLOW MAKES IT DIFFICULT TO FORECAST A DRY DAY 
ANYWHERE...BUT AT THIS POINT IT APPEARS THE MOISTURE WILL BE SHUNTED 
FAR ENOUGH EAST TO GO WITH SILENT 20 POPS INLAND ON SUNDAY AND 
MONDAY.  OTHERWISE DIURNAL CHANCE POPS THRU WEDNESDAY.  BERMUDA 
RIDGE STARTS TO BUILD IN A LITTLE STRONGER BY THURSDAY...SO WILL 
DROP OFF TO SILENT 20S AGAIN.   

TEMPS WILL BE LIMITED TO THE UPPER 80S FOR HIGHS FOR MUCH OF THE 
PERIOD DUE TO THE MOISTURE AND ABUNDANT CLOUD COVER...WITH THURSDAY 
AS THE BEST SHOT AT 90 DUE TO STRONGER RIDGING ALOFT.  MINS 
GENERALLY NEAR CLIMO...BUT COULD HAVE ENOUGH DRY AIR TO LET INLAND 
LOCATIONS DIP INTO THE MID 60S SUN NIGHT AND MON NIGHT.  

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
STILL A BIT OF UNCERTAINTY AS TO THE CONVECTION THIS AFTERNOON. NAM 
AND GFS MODELS SEEMS TO WANT TO BRING IN A DECENT AMOUNT OF 
CONVECTION AFTER 18Z. AT THIS TIME WILL GO FOR VCTS BECAUSE THE
COVERAGE WILL BE MINIMAL. SOUTHWEST WINDS WILL BECOME SOUTHERLY
EARLY...AND GUSTY...WITH THE RESULTANT. FAIRLY BENIGN CONDITIONS
EXPECTED OVERNIGHT WITH LITTLE OR NO FOG. MAIN SLUG OF MOISTURE
COMES IN FRIDAY MORNING...WITH A GOOD CHANCE FOR
SHOWERS/THUNDERSTORMS AFTER 15Z.
 
EXTENDED OUTLOOK THROUGH TUESDAY...SCATTERED THUNDERSTORMS FRIDAY 
AFTERNOON THROUGH SATURDAY MORNING. ISOLATED STORMS SUNDAY THROUGH 
TUESDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...SEAS 2 TO 3 FT AT THE MOMENT WITH GUSTY 
SOUTHERLY WINDS UP NEAR 15 KTS...ESPECIALLY CLOSE TO THE COAST IN 
THE SEA BREEZE THIS AFTERNOON. TIGHTENED GRADIENT FLOW BETWEEN 
PIEDMONT TROUGH AND BERMUDA HIGH WILL KEEP A SOLID 15 KTS ACROSS 
MUCH OF OUR LOCAL WATERS THROUGH TONIGHT. THIS WILL HELP TO PUSH 
SEAS UP TO 3 TO 4 FT THROUGH TONIGHT. 

SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM THURSDAY...SOUTHWEST FLOW CONTINUES THROUGH THE PERIOD 
WITH SPEEDS IN THE 15 TO 20 KT RANGE FOR A MAJORITY OF THE TIME. 
WATERS REMAIN STUCK BETWEEN BERMUDA HIGH AND PIEDMONT TROF ON FRI 
AND APPROACHING COLD FRONT SAT. SPEEDS WILL DECREASE LATE IN THE 
PERIOD AS FRONT MOVES TO THE COAST...BUT DIRECTION WILL REMAIN 
SOUTHWESTERLY. COMBINATION OF FAVORABLE FETCH AND SPEEDS IN THE 15 
TO 20 KT RANGE MAY LEAD TO HEADLINES BEING REQUIRED FRI 
NIGHT...POSSIBLY LASTING THROUGH THE END OF THE FORECAST PERIOD.

LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...EXPECT BENIGN WINDS AND SEAS THRU THE PERIOD 
WITH A DISSIPATING FRONT STALLED VERY CLOSE TO THE COASTAL WATERS.  
WIND SPEEDS LESS THAN 10 KT BUT THE DIRECTION IS MUCH HARDER TO PIN 
DOWN THRU AT LEAST MONDAY.  BY TUESDAY THE BERMUDA RIDGE STARTS TO 
HAVE MORE OF AN INFLUENCE.  WITH THE RIDGE AXIS TO THE 
NORTH...EXPECT WINDS TO BACK AROUND TO SE AS THE FRONT FINALLY 
WASHES OUT.   

SEAS GENERALLY 2-3 FT...BUT A BETTER SHOT AT SOME 4 FOOTERS CREEPING 
IN BY TUESDAY AS THE SE FETCH OPENS UP.  

&&

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

&&

$$
SYNOPSIS...RAS
NEAR TERM...RGZ
SHORT TERM...III
LONG TERM...III
AVIATION...RGZ/DL