-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 161128
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
728 AM EDT THU MAY 16 2013

.SYNOPSIS...
WARM TEMPERATURES WILL CONTINUE THROUGH EARLY NEXT WEEK AS HIGH
PRESSURE PUSHES OFFSHORE. THERE IS A SMALL RISK FOR MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS BEGINNING FRIDAY.

&&

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

SUMMER-LIKE PATTERN CONTINUES WITH HIGH PRESSURE ANCHORED OFFSHORE
AND A PIEDMONT-STYLE THERMAL TROUGH DEVELOPING INLAND. THIS
COMBINATION WILL KEEP UP A WARM SOUTHWESTERLY FLOW THROUGH THE
NEAR TERM...WITH ABOVE AVERAGE TEMPERATURES BOTH DAY AND NIGHT.
GUIDANCE IN GOOD AGREEMENT WITH TEMPERATURES...GIVING HIGHS IN THE
UPPER 80S MOST LOCATIONS...AND OVERNIGHT LOWS IN THE MID 60S.
STRONG SOUTHWESTERLY FLOW WILL KEEP SEA BREEZE FRONT PINNED NEAR
THE COAST AND EXPECT WE WILL SEE SOME CU DEVELOPMENT ALONG IT.
MODEL SOUNDINGS SHOW THAT THE ODD POP-UP SHOWER CANNOT BE RULED
OUT LATE THIS AFTERNOON...BUT ODDS ARE SO LOW THAT THERE WILL BE
NO MENTION OF CONVECTION IN THE FORECAST. MODEL SOUNDINGS AND
SATELLITE LOOPS SHOW MOSTLY SUNNY SKIES WILL PREVAIL TODAY...WITH
INCREASING HIGH CLOUDS OVERNIGHT.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...WEAK ZONAL FLOW ALOFT WITH LITTLE IN THE WAY
OF MID LEVEL SUPPORT SHIFTS THE FORECAST FOCUS TO SURFACE FEATURES
FOR MUCH OF THE PERIOD. INITIALLY PIEDMONT TROUGH AND BERMUDA HIGH
WILL BE THE KEY FEATURES...ALONG WITH AFTERNOON SEABREEZE...BUT
WEAKENING BACK DOOR COLD FRONT WILL DROP INTO CENTRAL NC LATE FRI.
AT THIS POINT IT SEEMS UNLIKELY THAT THE BOUNDARY WILL REACH THE
FORECAST AREA. THE ECMWF NO LONGER BRINGS IT SOUTH INTO THE AREA AND
THE GFS HAS REMAINING CONSISTENT IN KEEPING THE FRONT NORTH OF THE
AREA. LATEST NAM/CANADIAN ALSO SUPPORT KEEPING THE FRONT NORTH OF
THE AREA THROUGH SAT NIGHT.

ALTHOUGH IT APPEARS THAT THE FRONT WILL HAVE A VERY LIMITED IMPACT
ON THE REGION CONVECTION DEVELOPING ON THE BOUNDARY COULD RESULT IN
OUTFLOW MOVING INTO THE AREA. DESPITE THE POTENTIAL FOR AN ISOLATED
STORM DEVELOPING ON OUTFLOW THE PIEDMONT TROUGH AND SEABREEZE WILL
BE THE MAIN FOCUS FOR DIURNAL CONVECTION. DRY MID LEVEL AIR AND
WESTERLY FLOW ON FRI WILL HINDER AFTERNOON CONVECTION AS WELL AS
KEEP SEABREEZE PINNED NEAR THE COAST. WILL CONTINUE MENTIONABLE POP
BUT TRIM BACK TO SLIGHT CHANCE GIVEN THE LESS THAN FAVORABLE
CONDITIONS. SAT APPEARS MORE FAVORABLE WITH DEEPER MOISTURE
RETURNING ON SOUTHWEST MID LEVEL FLOW. PRECIPITABLE WATER VALUES
CLIMB TO 1.5 INCH BY MIDDAY AND MID LEVEL LAPSE RATES STEEPEN A
LITTLE. WILL MAINTAIN INHERITED DIURNAL CHC POP.

TEMPERATURES REMAIN ABOVE CLIMO THROUGH THE PERIOD. FRI WILL LIKELY
BE SLIGHTLY WARMER THAN SAT GIVEN MORE CLOUDS/CONVECTION EXPECTED
ALONG WITH FURTHER INLAND PENETRATION OF SEABREEZE. LOWS IN THE MID
60S ARE EXPECTED EACH NIGHT.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 3 AM THURSDAY...ILL DEFINED MID LEVEL PATTERN AND WEAK SURFACE
FEATURES LEAD TO A TYPICAL SUMMER TIME PATTERN FOR THE LONG TERM.
BACK DOOR COLD FRONT STALLED JUST NORTH OF THE AREA AT THE START OF
THE PERIOD WILL SLOWLY LIFT NORTH EARLY NEXT WEEK AS BERMUDA HIGH
SETS UP AND THEN STRENGTHENS. LOW LEVEL SOUTHWEST FLOW ALONG WITH
SOUTHWEST TO WEST MID LEVEL FLOW WILL PUMP PLENTY OF MOISTURE INTO
THE REGION NEXT WEEK. PRECIPITABLE WATER VALUES REMAIN ABOVE 1.5
INCH FOR VIRTUALLY THE ENTIRE PERIOD AND APPROACH 2 INCHES AT TIMES.
CONVERGENCE ALONG THE PIEDMONT TROUGH AND SEABREEZE COMBINED WITH
DIURNAL HEATING WILL PRODUCE AFTERNOON SHOWERS AND THUNDERSTORMS
EACH DAY. LATE IN THE PERIOD MID LEVEL RIDGING STARTS TO BUILD OVER
THE SOUTHEAST...HINDERING CONVECTION. TEMPERATURES WILL REMAIN ABOVE
CLIMO THROUGH THE PERIOD WITH HIGHS IN THE MID 80S TO AROUND 90 AND
LOWS IN THE LOW TO MID 60S.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
AS OF 12Z...EXPECT VFR THROUGH THE VALID TAF PERIOD. QUIET
CONDITIONS ARE ON TAP FOR TODAY AS CIRRUS WILL BECOME SCT IN NATURE
BY EARLY AFTERNOON...WITH FEW DIURNAL CU...AND SOUTHWEST WINDS
WILL INCREASE TO 10-15 KTS WITH GUSTS NEAR 20 KTS POSSIBLE. INTO
THE EVENING HOURS...GUSTS WILL SUBSIDE WITH SOUTHWEST WINDS AOB 8
KTS...BECOMING LIGHT OVERNIGHT. AS FOR CLOUD COVER...ANTICIPATE
COVERAGE TO INCREASE TO BKN/OVC OVERNIGHT...BECOMING SCT BY
FRIDAY MORNING.

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

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6:15 AM THURSDAY...SMALL CRAFT ADVISORY HAS EXPIRED ON TIME
AT 6 AM. BASED ON LATEST OBS AND FORECAST HAVE RAISED EXERCISE
CAUTION HEADLINES TODAY FOR OUR NC WATERS FOR 3 TO 5 FT SEAS AND
SW WINDS OF 15 TO 20 KT WINDS. SEAS FOR OUR SC WATERS ARE MORE IN
THE 2 TO 4 FT RANGE.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 AM THURSDAY...SOUTHERLY FLOW ACROSS THE WATERS WILL CONTINUE
THROUGH THE PERIOD AS BERMUDA HIGH REMAINS THE DOMINANT FORCE.
SLIGHTLY PINCHED GRADIENT FRI WILL LEAD TO WIND SPEEDS CLOSER TO 15
KT WHILE ON SAT 10 TO 15 KT IS MORE LIKELY. THERE WILL BE A WEAK
BACK DOOR COLD FRONT THAT STALLS NORTH OF THE AREA LATE FRI. AT THIS
POINT THE FRONT IS NOT EXPECTED TO HAVE AN IMPACT ON THE WATERS BUT
SHOULD IT DROP FARTHER SOUTH WINDS WOULD BECOME LIGHT AND VARIABLE
IN THE VICINITY OF THE FRONT SAT. SEAS 2 TO 4 FT ON FRI MAY SUBSIDE
A LITTLE FOR SAT...DOWN TO 2 TO 3 FT.

LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 AM THURSDAY...SUMMER PATTERN IN PLACE WITH BERMUDA HIGH THE
MAIN FEATURE. SOUTHERLY FLOW CONTINUES THROUGH THE PERIOD WITH
SPEEDS IN THE RANGE OF 10 TO 15 KT BOTH DAYS. SPEEDS MON MAY BE
MARGINALLY HIGHER AS GRADIENT BECOMES A LITTLE MORE DEFINED. SEAS 2
TO 3 FT ON SUN EXPERIENCE A SLIGHT INCREASE TO 2 TO 4 FT MON IN
RESPONSE TO INCREASE IN SPEEDS.

&&

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

&&

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