029 
FXUS62 KILM 240659
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
259 AM EDT FRI AUG 24 2012

.SYNOPSIS...
UPPER LEVEL DISTURBANCES AND A STALLED FRONT OFFSHORE WILL KEEP THE 
WEATHER UNSETTLED TODAY. SOME SLIGHTLY DRIER AIR WILL WORK INTO THE
AREA OVER THE WEEKEND. EARLY NEXT WEEK...ALL EYES WILL BE FOCUSED ON 
TROPICAL CYCLONE ISAAC TO OUR SOUTH AND ITS EVENTUAL TRACK. THE RISK 
FOR WET WEATHER WILL RETURN DURING TUESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 11 PM THURSDAY...STEADY LIGHT RAIN CONTINUES OVER THE CAPE 
FEAR REGION AND TO A SOMEWHAT LESSER AND LIGHTER EXTENT FURTHER 
INLAND OVER THE COASTAL COUNTIES. HAVE KEPT POPS ELEVATED ALONG THE 
COAST AS GUIDANCE AND RADAR TRENDS INDICATE ANOTHER ROUND OF RAIN 
POSSIBLE IN THE EARLY MORNING HOURS AS AN IMPULSE ADVANCES ALONG THE 
STALLED FRONT JUST OFFSHORE. SLIGHTLY ALTERED PREVIOUS DISCUSSIONS 
FOLLOW:

FLOODING IS LESS OF A CONCERN THAN EARLIER TODAY AS PRECIPITATION
IS NOW MOSTLY OF A LIGHT STRATIFORM NATURE. VERY LITTLE THUNDER
EXPECTED FOR THE REMAINDER OF THE NEAR TERM. WITH TEMPERATURES NOW
AROUND 70 MOST LOCATIONS IT LOOKS LIKE WE ARE ALREADY AT OF NEAR
FORECAST LOWS ABOUT EVERYWHERE.

A COLD FRONT NEARLY STATIONARY OFF THE CAROLINA COAST HAS ALLOWED
LIGHT NORTHEAST SURFACE WINDS TO SPREAD ALL THE WAY DOWN THROUGH
THE GRAND STRAND AND INTO GEORGETOWN SC. THE AIRMASS BEHIND THE
FRONT MAY BE SLIGHTLY COOLER BUT IS CERTAINLY STILL LOADED WITH
MOISTURE AS DEWPOINTS REMAIN IN THE 70S ACROSS ALL BUT OUR FAR
INLAND COUNTIES. PRECIPITABLE WATER VALUES FROM BOTH THE MODELS
AND FROM THE SATELLITE TOTAL PRECIPITABLE WATER (TPW) IMAGERY
RANGE FROM 1.75 TO 2.00 INCHES.

AN UPPER LEVEL DISTURBANCE CROSSING FROM THE FLORIDA PANHANDLE INTO 
SOUTH GEORGIA WILL SLIDE NORTHEAST AND OVER THE EASTERN CAROLINAS
LATE TONIGHT. THE TRAJECTORY OF THIS DISTURBANCE WILL BE CLOSE
ENOUGH TO THE COAST THAT INLAND AREAS (FLORENCE AND LUMBERTON) MAY
REMAIN GENERALLY DRY. ALONG THE COAST THE INCOMING UPPER
DISTURBANCE PLUS A 300 MB JET EXTENDING FROM COASTAL NC INTO THE
MID-ATLANTIC SHOULD HELP MAINTAIN SHOWERS THROUGH THE NIGHT. A
SURFACE LOW WILL ALSO DEVELOP ALONG THE STALLED FRONT TONIGHT BUT
SHOULD REMAIN TOO WEAK FOR ANY SIGNIFICANT IMPACTS ON OUR WEATHER.

LOWS TONIGHT SHOULD FALL INTO THE UPPER 60S AS SLIGHTLY COOLER
AIR IS DRAGGED IN ON NORTH WINDS LATE. WE MAY BE ABLE TO MAINTAIN
70-DEGREE LOWS ALONG THE COAST FROM WILMINGTON TO THE GRAND
STRAND...WITH WILMINGTON'S RECORD STRING OF 70+ DEGREE LOWS ON THE
LINE.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3:00 AM FRIDAY...MID LEVEL LOW PRESSURE WILL DRIFT SLOWLY TO THE 
NORTHEAST AS HIGH PRESSURE BUILDS IN. SATURDAY SHOULD BE DRY AS 
THERE IS NOW A CONSIDERABLE SUBSIDENCE INVERSION AROUND 800MB. THE 
PRECIPITABLE WATERS DROPPING TO JUST OVER ONE INCH MAY BE A BIT ON 
THE DRY SIDE AS THE GFS DOESNT SEEM TO BE HANDLING THE MASS OF DRY 
AIR ACROSS THE MISSISSIPPI VALLEY VERY WELL. THE HIGH RETREATS 
NORTHEAST SLIGHTLY SUNDAY AND SLIGHT CHANCE POPS ARE WARRANTED AS 
SOUNDINGS BECOME MORE FAVORABLE. 

TEMPERATURE FORECAST IS CHALLENGING AS THE 0000 UTC GUIDANCE IS ALL 
OVER THE PLACE. FOR EXAMPLE...THERE IS A SIX DEGREE SPREAD WITH 
WILMINGTON SATURDAY WITH WARMER MET NUMBERS. THERE IS ALSO A SIX 
DEGREE SPREAD IN LUMBERTON FOR SUNDAY WITH THE MAV MUCH WARMER. I 
HAVE GENERALLY LEANED TOWARD THE WARMER NUMBERS WHICH HAS BEEN A 
WINNING STRATEGY FOR MOST OF THE SUMMER.


&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3:00 AM FRIDAY...FORECAST CONFIDENCE REMAINS LOW AS SENSIBLE WEATHER 
ELEMENTS WILL BE MOSTLY DRIVEN BY THE EVENTUAL TRACK OF ISAAC. 
MAINTAINED THE HIGHER TREND OF POPS THROUGH THE PERIOD BUT 
SUBSEQUENT SHIFTS MAY WANT TO CONTEMPLATE INTRODUCING A DECREASING 
TREND AS ONLY LIMITED FORCING AND MOISTURE WILL BE AVAILABLE IF THE 
WESTERN SCENARIO/TRACK VERIFIES. THIS FORCING WILL BE BROAD SPEED 
CONVERGENCE WITH THE SOUTHEASTERLY FLOW WHICH GENERALLY DOESNT YIELD 
THAT MUCH FOR OUR AREA...AT LEAST INLAND. THE REMAINDER OF THE 
PERIOD WOULD BE MODULATED BY A WEAK FRONT LINGERING IN THE AREA. NO 
CHANGES TO TEMPERATURE FORECAST.

&&

.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM WILL 
BLOSSOM ACROSS THE AREA INTO FRI MORNING AS A POTENT DISTURBANCE 
MOVES UP THE COAST. THE BEST CHANCE FOR HEAVIER CONVECTION AND 
REDUCED CEILINGS AND VISIBILITIES WILL BE ALONG THE COAST WITH THE 
BEST CHANCE FOR THUNDERSTORMS AT THE COAST. FORECAST DOES INCLUDE 
IFR OR LOWER CEILINGS AT KILM/KCRE/KMYR THROUGH 12-16Z. CONDITIONS 
SHOULD IMPROVE ONLY SLOWLY FROM S TO N THEREAFTER. FURTHER 
INLAND...WHERE SHOWERS WILL BE MUCH MORE ISOLATED...WILL FORECAST 
TEMPO MVFR CONDITIONS THROUGH ABOUT 14Z...BUT EVEN HERE...THERE MAY 
BE A PERIOD OR TWO OF IFR THROUGH THE FIRST PART OF THIS MORNING.

VFR CONDITIONS SHOULD BEGIN TO PREVAIL IN WINDOW FROM 17Z TO 
22Z...LASTLY ALONG THE COAST AND TIL THE END OF THE TAF PERIOD.

EXTENDED OUTLOOK...ISOLATED SHOWERS AND THUNDERSTORMS SUN AND MON.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 11 PM THURSDAY...NO CHANGES TO THE FORECAST. THUNDER WILL BE 
MINIMAL. LATEST OBS SHOW SEAS IN THE 2 TO 3 FT RANGE...WITH 
LIGHT...GENERALLY NORTHERLY WINDS. PREVIOUS DISCUSSION FOLLOWS:

LIGHT NORTHEAST WINDS CONTINUE ACROSS THE COASTAL WATERS BEHIND A
FRONT WHICH IS NEARLY STATIONARY AT DISTANCES RANGING FROM 30 TO
70 MILES OFFSHORE. A WEAK WAVE OF LOW PRESSURE SHOULD ATTEMPT TO
DEVELOP ALONG THE FRONT TONIGHT OFF THE UPPER SOUTH CAROLINA COAST
WHICH WILL TEND TO PUSH THE BOUNDARY FARTHER OFFSHORE FROM
GEORGETOWN BUT MAY BRING THE FRONT CLOSER TO SHORE NEAR AND NORTH
OF CAPE FEAR. ACROSS THE COASTAL WATERS WINDS SHOULD BACK TO THE N
LATE TONIGHT IN EITHER CASE...WITH SPEEDS GENERALLY 10 KNOTS OR
LESS.

SHOWER ACTIVITY IS CURRENTLY AT A MINIMUM OVER THE COASTAL WATERS 
WITH THE BULK OF THE ACTIVITY CURRENTLY FOCUSED INLAND AND FARTHER 
OUT TOWARD THE GULF STREAM. THE SHOWERS WE HAVE OBSERVED ARE IN AN 
ENVIRONMENT WITH VERY LOW WIND SHEAR IN THE LOWEST 6000 FT OF THE 
ATMOSPHERE. WARM WATER TEMPERATURES ARE PROMOTING STEEP LOW-LEVEL 
LAPSE RATES AND AT LEAST ONE BATCH OF WATERSPOUTS HAVE BEEN THE 
RESULT. AS THE WAVE OF LOW PRESSURE DEVELOPS OFFSHORE EXPECT 
ADDITIONAL SHOWERS AND POTENTIALLY SOME THUNDERSTORMS TO REDEVELOP 
AND MOVE NORTH...ESPECIALLY LATE THIS EVENING AND AFTER MIDNIGHT.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3:00 AM FRIDAY...MOST OF THE FORECAST PERIOD WILL BE 
CHARACTERIZED BY LIGHT WIND FIELDS. SHOULD SEE NORTHEAST WINDS TEN 
KNOTS OR LESS THROUGH EARLY SUNDAY. WINDS VEER AND INCREASE TO 10-15 
LATER SUNDAY CONTINUING INTO EARLY MONDAY. SWAN IS ADVERTISING SEAS 
INCREASING FROM AN EARLY RANGE OF 2-4 FEET TO 3-6 FEET LATE VIA A 
SIGNIFICANT SWELL COMPONENT. 

LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3:00 AM FRIDAY...EXPECT NORTHEAST WINDS INITIALLY VEERING TO EAST 
LATE MONDAY AND FINALLY TO THE SOUTHEAST TUESDAY. SPEEDS WILL 
GENERALLY BE TEN KNOTS OR LESS. SOME LINGERING SWELL FROM DISTANT 
TROPICAL SYSTEM ISAAC AND JOYCE FOR THAT MATTER WILL KEEP SEAS 
HIGHER THAN WINDS FIELDS WOULD NORMALLY SIGNAL WITH 3-6 FEET BOTH 
DAYS. 

&&

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

&&

$$
SYNOPSIS...SHK
NEAR TERM...REK
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...RJD