338
FXUS62 KILM 041240
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
840 AM EDT SAT JUL 4 2009
SYNOPSIS
WEAK HIGH PRESSURE WILL REMAIN IN CONTROL TODAY. A COLD FRONT WILL
APPROACH SUNDAY AND MOVE THROUGH DURING THE OVERNIGHT HOURS. THIS
BOUNDARY WILL STALL VERY NEAR THE AREA TO THE SOUTH THROUGH THE
NEXT SEVERAL DAYS INTO NEXT WEEK.
NEAR TERM /THROUGH TONIGHT/
AS OF 9 AM SATURDAY...ANALYSIS OF MORNING SOUNDINGS SHOW A VERY
DRY AND STABLE ATMOSPHERE TODAY AS WEAK HIGH PRESSURE BUILDS IN.
NO SHOWERS TODAY...ONLY JUST ENOUGH MOISTURE AND HEATING FOR SOME
FAIR WX CU THIS AFTERNOON. SOME PASSING CIRRUS TOO ACCORDING TOT HE
LATEST SAT LOOPS AND TIME HEIGHT CROSS SECTIONS. HIGHS WILL BE
CLOSE TO NORMAL...UPPER 80S...WITH LOWS JUST A BIT ABOVE AS
SOUTHERLY FLOW STRENGTHENS OVERNIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/
AS OF 3 AM SATURDAY...MOISTURE INCREASING RAPIDLY ON SUNDAY WITH
THE APPROACH OF A PRETTY POTENT FRONT BY JULY STANDARDS. WARM
TONGUE AT H85 SURGES NICELY UP THE COAST LEADING TO GOOD
INSTABILITY DESPITE WHAT COULD BE RATHER EXTENSIVE CLOUD COVER.
BREAKS IN CLOUDS...WHICH ARE EXPECTED...WILL LEAD TO POCKETS OF
EVEN STRONGER INSTABILITY. THIS INSTABILITY COUPLED WITH GOOD
DIRECTIONAL SHEAR MAY LEAD TO A SUBSTANTIAL SEVERE WEATHER THREAT
AS FAIRLY POTENT SHORTWAVES CROSS THE AREA IN THE ZONAL MID LVL
FLOW. 00Z RUNS SHOW THE GREATEST OMEGA WITH THE ACTUAL FROPA
SUNDAY NIGHT IN THE 03-06Z TIMEFRAME. SPC DAY 2 OUTLOOK HIGHLIGHTS
ENTIRE AREA IN SLIGHT RISK. MAIN THREAT WILL BE DMG WIND AS WARM
TEMPS ALOFT WILL PRECLUDE HAIL AND LL SHEAR IS INSUFFICIENT FOR
ANYTHING OTHER THAN VERY SMALL TORNADO THREAT.
AS THE FRONT TAKES ON A MORE E-W ORIENTATION MONDAY IT WILL ALIGN
WITH THE FLOW ALOFT...SLOWING ITS SOUTHWARD PROGRESS. RAIN CHANCES
WILL THUS TAPER OFF SLOWLY FROM N TO S. LOWER DEWPOINTS AT THE SFC
ALSO ADVECTING INTO WESTERN ZONES BY AFTERNOON. TEMPERATURES WILL
BE HELD TO A FEW DEGREES BELOW CLIMO.
LONG TERM /TUESDAY THROUGH FRIDAY/
AS OF 3 AM SATURDAY...COLD FRONT LIES STALLED VERY CLOSE TO THE
AREA...JUST TO THE SOUTH ON TUESDAY. STILL CLOSE ENOUGH TO WARRANT
SLIGHT CHANCE POPS AREA-WIDE ALTHOUGH SLIGHTLY LOWER CHANCES
WITHIN THE RANGE EXPECTED NRN ZONES. THIS BOUNDARY SHOULD REMAIN
IN PLACE THROUGH THE REST OF THE LONG TERM. THIS WILL KEEP A
SLIGHT CHANCE FOR POPUP SHOWERS OR STORMS EACH DAY. TEMPERATURES
PRETTY CLOSE TO CLIMO THROUGHOUT SAVE FOR POSSIBLY A SLIGHTLY
COOLER TUESDAY NIGHT AS LOWER DEWPOINTS LIE OVER THE REGION.
AVIATION /13Z SATURDAY THROUGH WEDNESDAY/
NO AVIATION CONCERNS THROUGH THE FORECAST PERIOD WITH VFR
CONDITIONS EXPECTED. LIGHT AND VARIABLE WINDS THIS
MORNING...BECOMING SOUTH SOUTHEAST ALONG THE COAST WITH THE SEA
BREEZE BOUNDARY. DRY AIR ALOFT AND SUBSIDENCE WILL PREVENT
CONVECTION...ONLY ISOLATED CU FORMATION. LIGHT WINDS OVERNIGHT.
EXTENDED OUTLOOK THROUGH WEDNESDAY...SCATTERED THUNDERSTORMS
SUNDAY AFTERNOON THROUGH MONDAY.
MARINE
NEAR TERM /THROUGH TONIGHT/...
AS OF 9 AM SATURDAY...WINDS WILL BE LIGHT AND NORTHERLY THIS
MORNING AND THEN AS HIGH PRESSURE SHIFTS SEAWARD IT WILL BECOME
LIGHT AND VARIABLE. EXPECT A S TO SW WIND REGIME TO OVERTAKE THE
WATERS LATER THIS MORNING. WINDS WILL BE STRONGEST NEAR SHORE
THIS AFTERNOON DUE TO SEABREEZE INFLUENCES. OVERALL GRADIENT WILL
BEGIN TO TIGHTEN WITH A SSW-SW LOW LEVEL JET DEVELOPING TONIGHT.
THEREFORE...WE ARE EXPECTING WINDS AND SEAS TO BEGIN TRENDING
HIGHER THIS PERIOD WITH THAT TREND CONTINUING BEYOND THIS FORECAST
PERIOD.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...FAIRLY TYPICAL SOUTHWESTERLY WINDS IN THE
10-15 KT RANGE TO START SUNDAY LASTING INTO EARLY AFTERNOON. THE
APPROACH OF A COLD FRONT LATER IN THE DAY WILL TIGHTEN THE
GRADIENT AND INCREASE THE WINDS TO 20 KTS OR SO FAIRLY QUICKLY
WITH HIGHEST SPEEDS EXPECTED CLOSE TO MIDNIGHT AS THE FRONT NEARS
THE COASTLINE. AT THIS TIME THERE IS PROGGED TO BE SOME 6 FT SEAS
AT 41013 BUT THEY SHOULD REMAIN OUTSIDE OF THE FCST AREA AND SMALL
CRAFT ADVISORY NOT EXPECTED BUT SCEC HEADLINE CANNOT BE RULED OUT.
SOON THEREAFTER WINDS WILL BEGIN TO VEER TO WESTERLY. FURTHER
VEERING AND MUCH LIGHTER SPEEDS EXPECTED ON MONDAY AS THE PRESSURE
TROUGH ASSOC WITH THE FRONT BRINGS LIGHT GRADIENT ACROSS THE
WATERS. LIGHT WINDS ACQUIRE A NORTHERLY COMPONENT MONDAY NIGHT AS
THE BOUNDARY SLOWLY CONTINUES TO SINK TO THE SOUTH.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...WINDS APPEAR TO BE DESTINED TO REMAIN QUITE
LIGHT THROUGH THE LONG TERM THANKS TO A BOUNDARY SITTING STALLED
VERY CLOSE TO THE SOUTH. WEAK WAVES OF LOW PRESSURE RIPPLING ALONG
THE BOUNDARY WILL CAUSE NORTH-SOUTH UNDULATIONS IN ITS POSITION
WHICH IS MAKING THE WIND DIRECTION FORECAST PROBLEMATIC.NORTHEAST
WINDS ON THE N SIDE OF THE BOUNDARY COULD QUICKLY TURN TO THE S
ANYWHERE ALONG AND SOUTH OF THE FRONT. FUTURE MODEL RUNS SHOULD
SHED MORE LIGHT ON THE POSITIONING OF THE FRONT THROUGH THE
MIDWEEK PERIOD.
ILM WATCHES/WARNINGS/ADVISORIES
SC...NONE.
NC...NONE.
MARINE...NONE.
SYNOPSIS...REK
NEAR TERM...REK
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