000 FXUS62 KILM 021357 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 957 AM EDT TUE JUN 2 2009 .SYNOPSIS... WARM AND HUMID CONDITIONS WILL PERSIST FOR THE NEXT FEW DAYS. A COLD FRONT IS EXPECTED TO ENTER THE AREA LATE THURSDAY OR FRIDAY AND SHOULD STALL ALONG THE COAST SATURDAY. THIS BOUNDARY WILL WASH OUT BY SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 9 AM TUESDAY...THE WEAK UPPER DISTURBANCE THAT HELPED FIRE YESTERDAYS SEVERE CONVECTIVE OUTBREAK IS JUST OFF THE COAST. UPPER LEVEL WINDS ARE VERY LIGHT BUT THERE IS A LITTLE WEAK NVA/SUBSIDENCE OVER THE EASTERN CAROLINAS THIS AFTERNOON. COMPARED TO YESTERDAY...THE ATMOSPHERE IS DRIER AND THEREFORE NOT QUITE AS UNSTABLE. MODEL CAPE AT 1800Z RANGES FROM 500-1000 J/KG INLAND TO AS HIGH AS 2500-3000 J/KG IN THE CAPE FEAR AREA. THE GFS AND NAM HINT AT A LITTLE CONVECTION INLAND FROM THE COAST THIS AFTERNOON...BUT THE NSSL WRF MODEL (AVAILABLE ONLINE) HAS WHAT WE FEEL IS THE BEST DEPICTION: ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP ALONG THE SEABREEZE 10-15 MILES INLAND BETWEEN 1-2 PM. THE SEABREEZE WILL PUSH WEST...AIDED BY OUTFLOWS FROM THE PULSE-TYPE CONVECTION. AS THE CONVECTION DISCONTINUOUSLY REDEVELOPS INLAND IT WILL ENCOUNTER DRIER AIR AND BECOME MORE AND MORE ISOLATED IN NATURE. THE LAST CELLS WILL FINALLY DRY UP BETWEEN 4-5 PM AND IS NOT EXPECTED TO REACH AS FAR WEST AS INTERSTATE 95. THE SPC DID NOT INDICATE A RISK OF SEVERE WEATHER FOR THE AREA YESTERDAY AND THAT FORECAST IS REPEATED AGAIN TODAY. NAM AND GFS FORECAST SOUNDINGS ACROSS COLUMBUS AND INLAND HORRY COUNTIES SHOW A THICK CAPE AREA WHICH CAN BE SUPPORTIVE OF HIGH UPDRAFT VELOCITIES AND HAIL. WE WILL BE CLOSELY WATCHING FOR RADAR VIL VALUES > 55 KG/M*2 GIVEN 500 MB TEMPERATURES AROUND -11C. HIGHS TODAY SHOULD RANGE FROM THE LOWER TO MID 80S AT THE COAST TO THE LOWER 90S INLAND. HUMIDITY SHOULD REMAIN LOW ENOUGH INLAND TO PREVENT SIGNIFICANT RISES TO THE APPARENT TEMPERATURE ABOVE THE AMBIENT AIR TEMPERATURE. AT THE COAST HIGHER DEWPOINTS WILL PUSH HEAT INDICES 3-5 DEGREES ABOVE THE ACTUAL AIR TEMP. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...FORECAST SOUNDINGS SHOW ENOUGH DRY AIR ON WED (PWATS AROUND 1.0 INCH) THAT MOST OF THE AREA SHOULD STAY DRY. THERE COULD BE ABOUT 10-15 PERCENT COVERAGE OF THUNDERSTORMS WHERE THE SEA BREEZE MANAGES TO LIFT A PARCEL TO LFC. COLUMN MOISTENS INTO THURS WITH PWATS APPROACHING 1.5 INCHES AS SFC BOUNDARY AND UPPER TROUGH ENCROACH UPON THE CAROLINAS FROM THE WEST. WRF GUIDANCE SHOWING SURPRISING RESTRAINT WITH CONVECTIVE SIGNALS LOCALLY...KEEPING MOST OF THE ACTION TO THE NW. GFS HAS TOO MUCH GRID SCALE FEEDBACK TO BE VERY USEFUL IN THE 00Z RUN. WRF MAY BE ON TO SOMETHING THOUGH AS THE AREA MAY VERY WELL LIE IN A RELATIVE MINIMUM IN CONVECTION. ONE AREA OF STORMS WILL BE ALONG THE GULF COAST WITH SRN UPPER WAVE AND SFC LOW ON THE FRONT. THE OTHER WILL MOVE OUT OF THE OH VALLEY AND INTO THE MID ATLANTIC REGION WITH NORTHERN BRANCH. CURRENT FCST HAS A NW TO SE GRADATION OF POPS FROM 25-40...HIGHEST NW THRU PM AND ABOUT A 10-15 PERCENT INCREASE ACRS THE BOARD THURS NIGHT AS FRONT NEARS...BRINGING LIKELY POPS INTO NWRN ZONES. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 3 AM TUESDAY...COLD FRONT DROPS INTO THE AREA FRI AND PARALLELS THE COAST SAT. THIS SHOULD LEAD TO FAIRLY UNSETTLED WX THRU THE PD ESP IF SOME OF THE TRAILING SFC WAVES SHOWING UP IN GUIDANCE COME TO PASS. THIS FRONT SHOULD PROBABLY WASH OUT FOR THE MOST PART BY SUNDAY. THERE WILL NOT BE MUCH DRYING OF THE COLUMN BEHIND IT SO THE SEABREEZE AND ANY LINGERING OR REDEVELOPING INLAND TROUGHINESS SHOULD BE ABLE TO YIELD DIURNAL CONVECTION WITHOUT MUCH DIFFICULTY. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... ANOTHER TYPICAL SUMMER TYPE PATTERN. THE CAPE IS NOT AS IMPRESSIVE AS YESTERDAY...SO ANY CONVECTION ALONG THE SEA BREEZE BOUNDARY WILL BE QUITE ISOLATED. ANY LIGHT FOG AT THE START TIME OF THE THE TAFS WILL QUICKLY DISSIPATE WITH MORNING HEATING. SLIGHT CHANCE OF SOME RESTRICTED VISIBILITY DUE TO HAZE...BUT NO WORSE THAN 6SM. LIGHT WEST SOUTHWEST WIND WILL BECOME SOUTH SOUTHWEST WITH THE RESULTANT. LIGHT WINDS OVERNIGHT WITH A CHANCE OF SOME LIGHT FOG TOWARDS MORNING...HEAVIEST WHERE THERE WAS PRECIP IN THE AFTERNOON. EXTENDED OUTLOOK THROUGH SATURDAY...POSSIBLE MORNING IFR WEDNESDAY DUE TO FOG/LOW STRATUS. ISOLATED AFTERNOON THUNDERSTORMS WEDNESDAY. SCATTERED THUNDERSTORMS THURSDAY. THUNDERSTORMS LIKELY THURSDAY NIGHT AND FRIDAY. SCATTERED STORMS SATURDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 9 AM TUESDAY...LIGHT SOUTHWEST WINDS WILL BACK AROUND TO THE SOUTH THIS AFTERNOON WITH A MODERATE SEABREEZE CIRCULATION EXPECTED TO DEVELOP. SPEEDS NEARSHORE WILL INCREASE TO 10-15 KT DURING THE AFTERNOON AND EARLY EVENING. SEAS ARE CURRENTLY 1-2 FT AND LITTLE CHANGE IS EXPECTED THROUGH THE DAY. THUNDERSTORM ACTIVITY SHOULD REMAIN INLAND TODAY WILL VERY LITTLE POTENTIAL FOR ANYTHING AFFECTING THE COASTAL WATERS. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 AM TUESDAY...PRETTY TYPICAL BERMUDA HIGH-INDUCED SWRLY WINDS IN THE 10 TO 15 KT RANGE FOR MOST OF WED. A WARM FRONT MAY BACK THE FLOW BRIEFLY TO SE WED NIGHT ESP OVER NRN WATERS. THIS BOUNDARY WILL REMAIN NOT TO FAR TO THE NORTH THURSDAY WHILE SRN ZONES ARE SITUATED IN A SLIGHTLY STRENGTHENING WARM ADVECTION ZONE OF SRLY WINDS. SEAS WILL BUILD IN THIS AREA TOWARDS THE END OF THE PD...POSSIBLY AS HIGH AS 3 TO 5 FT. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3AM TUESDAY...FRIDAY WIND FCST STILL HINGING UPON THE POSITION OF COLD FRONT THAT SHOULD ENTER THE WATERS LATE IN THE DAY. WINDS INITIALLY SW POSSIBLY VEERING WITH THE APPROACH OF THE BOUNDARY ESP OVER NRN ZONES. WINDS WILL BE LIGHT AS THE BOUNDARY STILL STALLS CLOSE TO THE COAST SAT. THE FEEDBACK-INDUCED SFC WAVE ON THE GFS HAS RENDERED WNA GUIDANCE FAIRLY UNUSABLE. CURRENT SEAS FCST A BLEND OF CONTINUITY AND WIND TO WAVE NOMOGRAM AND SHOWS MORE OR LESS A CONTINUATION OF 2 TO 4 FT THROUGH MOST OF THE PD. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...BACON NEAR TERM...TRA SHORT TERM...BACON LONG TERM...BACON AVIATION...43