-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 171145
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
745 AM EDT FRI MAY 17 2013

.SYNOPSIS...
WARM TEMPERATURES WILL CONTINUE INTO EARLY NEXT WEEK AS BERMUDA
HIGH PRESSURE REMAINS ANCHORED OFFSHORE. A MID LEVEL DISTURBANCE
WILL BRING INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS OVER
THE WEEKEND INTO EARLY NEXT WEEK. DRIER WEATHER IS EXPECTED
THROUGH THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 6:15 AM FRIDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:

ANOTHER DAY OF SUMMER-LIKE CONDITIONS AS A WARM SOUTHWESTERLY FLOW
CONTINUES AROUND THE BACK SIDE OF HIGH PRESSURE OVER THE WESTERN
ATLANTIC. GUIDANCE IN VERY GOOD AGREEMENT WITH HIGHS IN THE UPPER
80S MOST LOCATIONS AND MID 80S AT THE BEACHES. A COLD FRONT
DROPPING SOUTH TOWARDS THE AREA OVERNIGHT WILL STALL JUST TO OUR
NORTH BY DAYBREAK ON SATURDAY.

FORECAST CONVECTIVE INDICES AS DERIVED FROM MODEL SOUNDINGS SHOW
THAT ISOLATED CONVECTION IS A POSSIBILITY THIS AFTERNOON AND
EVENING. WILL ALSO BE KEEPING IN THE SLIGHT CHANCE FOR CONVECTION
AFTER MIDNIGHT...PRIMARILY FOR OUR NORTHERN COUNTIES...AS THE
AFOREMENTIONED COLD FRONT AND AN UPPER LEVEL WEAKNESS APPROACH THE
AREA.

WARM SOUTHWESTERLY FLOW WILL HELP KEEP OVERNIGHT TEMPERATURES
ELEVATED ABOVE NORMAL...WITH MINIMUMS IN THE MID 60S.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...WEAK PATTERN ALOFT COUPLED WITH BERMUDA HIGH AND
PIEDMONT TROUGH WILL RESULT IN AFTERNOON SHOWERS AND THUNDERSTORMS
SAT AND SUN. FOR SAT FLOW ALOFT REMAINS ZONAL AND FORECAST SOUNDINGS
SHOW SOME DRY AIR THROUGH THE COLUMN. STILL ANTICIPATE SOME STORM
DEVELOPMENT ALONG PIEDMONT TROUGH AND SEABREEZE BUT COVERAGE AND
STRENGTH WILL BE LIMITED.

COVERAGE SHOULD INCREASE SUN AS DEEPER MOISTURE ARRIVES AND WEAK 5H
SHORTWAVE TROUGH SLOWLY MOVES INTO BUILDING MID LEVEL RIDGE. MID
LEVEL LAPSE RATES REMAIN WEAK BUT FORECAST SOUNDINGS SHOW A
SIGNIFICANT INCREASE IN MOISTURE WITH PRECIPITABLE WATER VALUES
AROUND 1.9 INCH BY AFTERNOON. STEEP LOW LEVEL LAPSE RATES AND
PRESENCE OF PIEDMONT TROUGH AND SEABREEZE HELP GENERATE CONVECTION.
DEEPER MOISTURE AND ENHANCEMENT ALOFT WILL HELP SUSTAIN DEEPER
CONVECTION RESULTING IN WIDESPREAD AFTERNOON SHOWERS AND
THUNDERSTORMS. WEAK MID LEVEL LAPSE RATES...LIMITED DRY LOW LEVEL
AIR AND LACK OF STRONG JETTING SUGGEST STORMS WILL NOT BECOME SEVERE.

HIGHS WILL BE NEAR TO SLIGHTLY ABOVE CLIMO WITH WARM ADVECTION BEING
OFFSET SOMEWHAT BY CLOUD COVER...ESPECIALLY ON SUN. LOWS WILL REMAIN
SEVERAL DEGREES ABOVE CLIMO EACH NIGHT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...DEEP MOISTURE AND WEAKNESS IN BUILDING MID LEVEL
RIDGE LINGERS OVER THE ARE MON...ONCE AGAIN CREATING AN ENVIRONMENT
SUPPORTIVE OF WIDESPREAD SHOWERS AND THUNDERSTORMS. AS IS THE CASE
ON SUN SEVERE PARAMETERS ARE LACKING SO STORMS ARE EXPECTED TO
REMAIN SUB-SEVERE.

PRECIP CHANCES START TO DECREASE TUE AS 5H RIDGE CONTINUES TO BUILD
IN FROM THE EAST AND THE WEAKNESS IN THE RIDGE FILLS IN. REMAINDER
OF THE PERIOD WILL BE DOMINATED BY THE 5H RIDGE AND THE BERMUDA
HIGH. FORECAST SOUNDINGS SHOW DRY AIR BELOW 12FT TUE EXPANDING
THROUGH THU AS SUBSIDENCE INVERSION STRENGTHENS. ABUNDANT MOISTURE
ABOVE 15K FT MAY KEEP CIRRUS AROUND THROUGH THE PERIOD BUT PRECIP
CHANCES WILL BE DIMINISHED. LATE IN THE PERIOD A COLD FRONT
APPROACHES FROM THE NORTHWEST BUT ITS ARRIVAL WILL BE WELL BEYOND
THE END OF THE PERIOD SO IT IS NOT A FACTOR AT THIS POINT.

HIGHS WILL BE WITHIN A FEW DEGREES OF CLIMO MON AND TUE BUT CLIMB
WELL ABOVE CLIMO BY THE END OF THE PERIOD. LOWS WILL REMAIN WELL
ABOVE CLIMO THROUGH THE PERIOD.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
AS OF 12Z...ANOTHER HOUR OR TWO OF PATCHY FOG THIS MORNING
INLAND...WITH THE POTENTIAL FOR FOG AGAIN SATURDAY MORNING.
OTHERWISE EXPECT VFR.

MID TO HIGH CLOUDS LINGERING ACROSS THE AREA THIS MORNING...WITH
TEETERING MVFR/IFR FOG AT KLBT. EXPECT FOG TO DISSIPATE WITHIN THE
NEXT HOUR OR TWO...GIVING WAY TO VFR AREA-WIDE FOR THE REST OF THE
DAY WITH SCT/BKN MID TO HIGH LEVEL CLOUDS. SOUTHWEST WINDS AOB 10
KTS EXPECTED TODAY...BECOMING SOUTH ALONG THE COAST WITH THE
AFTERNOON SEABREEZE. WOULD NOT COMPLETELY RULE OUT AN ISOLATED
SHOWER OR THUNDERSTORM THIS AFTERNOON...BUT CONFIDENCE IS LOW.
INTO THE OVERNIGHT HOURS...CLOUD COVERAGE WILL CONTINUE...AND
LIKELY INCREASE...WITH WINDS BECOMING LIGHT. TOWARDS THE EARLY
MORNING HOURS ON SATURDAY...CANNOT RULE OUT PATCHY
FOG...ESPECIALLY INLAND.

EXTENDED OUTLOOK...CHANCE OF AFTN SHOWERS/TSTMS SATURDAY THROUGH
MONDAY...OTHERWISE VFR.
-- End Changed Discussion --


&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6:15 AM FRIDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:

STEADY SOUTHWESTERLY FLOW CONTINUES AROUND THE BACK SIDE OF A HIGH
PRESSURE SYSTEM OVER THE WESTERN ATLANTIC. WINDS WILL BE IN THE 10
TO 15 KT RANGE WITH 2 TO 4 FT SEAS THROUGH THE NEAR TERM.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...SOUTHWEST FLOW WILL CONTINUE THROUGH THE PERIOD
AS BERMUDA HIGH REMAINS IN CONTROL. GRADIENT WILL PRODUCE SPEEDS IN
THE 10 TO 15 KT RANGE WITH SPEEDS EACH AFTERNOON ON THE HIGHER END
OF THE RANGE. SEAS WILL RUN 2 TO 4 FT WITH SOUTHEAST SWELL BECOMING
A LITTLE MORE APPARENT.

LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM FRIDAY...SUMMER PATTERN CONTINUES WITH BERMUDA HIGH
KEEPING SOUTH TO SOUTHWEST FLOW BETWEEN 10 AND 15 KT. HIGHEST SPEEDS
WILL OCCUR IN THE AFTERNOON. SEAS 2 TO 4 FT THROUGH THE PERIOD WILL
BE A MIX OF WIND WAVE AND SOUTHEAST SWELL.

&&

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

&&

$$

NEAR TERM...REK
SHORT TERM...III
LONG TERM...III
AVIATION...SGL
MARINE...REK/III