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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 171723
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
123 PM 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/...
-- Changed Discussion --
AS OF 1:30 PM FRIDAY...CONVECTIVE DEVELOPMENT HAS BEEN MEASURED AS EXPECTED
THIS AFTERNOON AS CUMULUS CLOUDS ARE JUST NOW BEGINNING TO
DEVELOP. THE LATEST GUIDANCE INCLUDING THE HIGH RESOLUTION RAP AND
GLOBAL GFS SHOW SOME ACTIVITY TO THE NORTH LATER THIS AFTERNOON. I
HAVE TWEAKED THE POPS TO REPRESENT THIS TREND OF WHICH THE FORCING
INCLUDES THE SEA BREEZE FRONT...POSSIBLY A RESIDUAL OUTFLOW FROM
ACTIVITY YESTERDAY AND A BACKDOOR FRONT. FOR THE OVERNIGHT
HOURS...I HAVE REMOVED POPS AFTER 0300 UTC. ENOUGH DEBRIS
CLOUDINESS SHOULD REMAIN TO PREVENT ANY SIGNIFICANT FOG
DEVELOPMENT. FOR THE OVERNIGHT LOWS...NUMERICAL GUIDANCE IS IN
EXCELLENT AGREEMENT WITH MIDDLE 60S ACROSS THE BOARD.
-- End Changed Discussion --

&&

.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 /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
AS OF 18Z...EXPECT VFR THROUGH THE VALID PERIOD...WITH THE EXCEPTION
OF POSSIBLE AREAS OF FOG SATURDAY MORNING.

FOR THE REST OF THE DAY EXPECT SCT/BKN MID TO HIGH LEVEL CLOUDS WITH
SOUTHWEST WINDS AOB 10 KTS...BECOMING MORE SOUTH ALONG THE COAST
WITH THE AFTERNOON SEABREEZE. WOULD NOT COMPLETELY RULE OUT AN
ISOLATED SHOWER 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.
TIME-HEIGHT ANALYSIS AND FCST SOUNDINGS SUGGEST POSSIBILITY OF
FEW/SCT LOW CLOUDS IN THE MORNING AS WELL. AFTER DAYBREAK...CLOUDS
WILL GRADUALLY BEGIN TO SCATTER OUT WITH SOUTHWEST WINDS AOB 8 KTS.

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

&&

.MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 PM FRIDAY...PERSISTENCE WILL BE THE THEME FOR THE COASTAL
WATERS THROUGH TONIGHT AS A SOUTHWEST FLOW OF 10-15 KNOTS PREVAILS.
WAVEWATCH SEAS WILL CONTINUE IN A 2-4 FOOT RANGE. THE BACKDOOR FRONT
SHOULD STAY WELL TO THE NORTH PRECLUDING ANY WIND SHIFT.

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.
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...SHK
NEAR TERM...SHK
SHORT TERM...III
LONG TERM...III
AVIATION...SGL