000 FXUS62 KILM 231731 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 1231 PM EST MON NOV 23 2009 .SYNOPSIS... LOW PRESSURE WILL MOVE SLOWLY NORTHEAST ALONG THE CAROLINA COAST TODAY. ALTHOUGH THE WIDESPREAD RAIN WILL END EARLY...AREAS OF DRIZZLE AND FOG WILL DEVELOP AND PERSIST INTO TUESDAY. WEDNESDAY AND THURSDAY WILL FEATURE A BRIEF WARM-UP...BUT A COLD FRONT LATE THURSDAY WILL BRING MUCH COLDER CONDITIONS AND THE POSSIBILITY OF FROST OR A FREEZE FOR THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 10 AM MONDAY...FORECAST IS BEHAVING ACROSS MOST OF THE FORECAST AREA. ONLY ISSUES ARE ALONG THE NC COAST...WHICH WAS EXPECTED TO BE A PROBLEM. SOME CLEARING HAS DEVELOPED OVER THE COASTAL COUNTIES AND HAS ALLOWED TEMPS TO JUMP A FEW DEGREES. TWEAKED HIGHS UP A COUPLE DEGREES FOR THE NC COAST BUT WITH MORE CLEARING TEMPS COULD TOP OUT AROUND 70. ELONGATED SURFACE LOW OFF THE SOUTH CAROLINA COAST IS SLOWLY WORKING ITS WAY NORTHEAST AND WILL KEEP SURFACE WINDS OUT OF THE NORTHEAST. RADAR ECHOS HAVE TAKEN ON LOOK MORE CHARACTERISTIC OF CONVECTIVE SHOWERS AS OPPOSED TO STRATIFORM RAIN. FORECAST SOUNDINGS SUGGEST THERE MAY BE A LAYER OF WEAK INSTABILITY FROM 925 TO 700 MB WHICH IS ALLOWING SOME ELEVATED CONVECTION TO DEVELOP. ABOVE THIS THERE IS A STRONG SUBSIDENCE INVERSION...SO CANNOT SEE ANY THUNDER FROM THESE BUT COULD SEE LITTLE POCKETS OF ENHANCED PRECIP FOR A FEW MINUTES. FORECAST SOUNDINGS ALSO SHOW THE SUBSIDENCE INVERSION BECOMING STRONGER DURING THE AFTERNOON HOURS WHICH SHOULD SHUT OFF ANY ELEVATED CONVECTION BY THE AFTERNOON HOURS. MOST OF THE STRATIFORM PRECIP HAS ENDED AND IS SHIFTING TO POCKETS OF LIGHT DRIZZLE. SATURATED LAYER IS PRETTY SHALLOW...WHICH SHOULD KEEP DRIZZLE CONFINED TO SMALL PATCHES. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... AS OF 3 AM MONDAY...LARGE DIFFERENCE IN HIGH TEMPERATURE GUIDANCE CONTINUES TO BE SEEN FOR TUESDAY. COOL AIR WEDGE PROGGED TO KEEP CLOUDS IN THE FCST AND EVEN SOME MORNING FOG AND/OR DRIZZLE. THE LAYER OF MOISTURE ASSOCIATED WITH THE WEDGE IS VERY THIN WITH VERY DRY AIR ABOVE. THE DIFFERENCE IN TEMP GUIDANCE IS ASSOC WITH WHETHER OR NOT THAT SHALLOW LAYER OF MOISTURE CAN MIX OUT. IF SO...THEN THE AFTERNOON COULD TURN OUT NICE WITH SUNSHINE AND HIGHS IN THE MID 60S. IF NOT...AS CURRENTLY FORECASTED...THEN TEMPS WILL STAY MIRED IN THE 50S. PREFRONTAL MID LEVEL MOISTURE LOOKS A LITTLE FASTER THAN PREV FORECASTED FOR WED...POSSIBLY NOT ALLOWING ANY BREAK FROM TUESDAYS MID LEVEL CLOUDINESS AND KEEPING WED COOLER THAN CLIMO AGAIN. WEAK LOW INDUCED OFF THE COAST ON THE OLD FRONTAL BOUNDARY TO BRING SOME SLIGHT CHANCES FOR MEASURABLE RAINFALL AS WELL THAT WILL PERSIST INTO WEDNESDAY NIGHT. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 3 AM MONDAY...GUIDANCE GETTING A LITTLE MORE AGGRESSIVE WITH THE COLD TEMPS TO FOLLOW THURSDAYS COLD FRONT. FROPA ITSELF WILL BRING ONLY LOW END CHANCE POPS AS MOISTURE WILL BE LIMITED DESPITE SOME PRETTY STRONG DYNAMICS. FRIDAY HIGHS SHOULD STRUGGLE TO REACH 60 AND LOW TO MID 30S ACROSS THE BOARD FRIDAY NIGHT. MODERATION WILL BE MINIMAL FOR THE REMAINDER OF THE WEEKEND SO HIGHS AND LOWS WILL BOTH BE A FEW DEGREES BELOW CLIMO. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... LOW PRESSURE OFF THE SOUTHEAST NORTH CAROLINA COAST WILL SLIDE UP THE COAST TODAY AND PROVIDE AN ABUNDANCE OF WRAP AROUND MOISTURE TO SUSTAIN IFR CEILINGS FOR THE TAF SITES. ONLY ILM WILL MAINTAIN MVFR WITH CEILINGS FOR THE NEXT FEW HOURS...OTHERWISE IFR/LIFR WILL BE THE RULE TODAY AND TONIGHT THROUGHOUT THE TERMINALS. LOW CEILINGS FROM THE PERSISTENT ONSHORE FLOW WILL EXTEND FROM THE COAST TO THE INLAND STATIONS. VISIBILITIES WILL HOLD AT VFR TO MVFR UNTIL 05Z TIME FRAME...THEN START DROPPING TO MVFR THEN TO IFR BY 07Z. WIND TO BE NORTHERLY 6 TO 14 KNOTS TODAY AND DIMINISH TO 3 TO 8 KNOTS THIS EVENING. EXTENDED OUTLOOK...IFR CEILINGS CONTINUE THROUGH TUESDAY. IFR VISIBILITIES IN FOG POSSIBLE EACH MORNING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 10 AM MONDAY...ENDED SCA FOR SC WATERS BUT RAISED AN SCEC WITH SEAS CONTINUING A SLOW DECREASE THROUGH THE MORNING HOURS. NORTHEAST FLOW WILL CONTINUE AS ELONGATED SURFACE LOW PASSES JUST EAST OF THE WATERS. APPROACH OF LOW WILL BE CLOSE ENOUGH THAT WINDS MAY BECOME LIGHT AND HIGHLY VARIABLE LATER TODAY...ESPECIALLY ACROSS NC WATERS. OVERALL DID NOT MAKE MUCH CHANGE TO PREVIOUS FORECAST. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 AM MONDAY...WEAK COOL WEDGE OF HIGH PRESSURE UP AND DOWN THE EAST COAST WILL PERSIST THROUGH THE SHORT TERM PERIOD. LOOK FOR A NORTH TO NORTHEAST WIND GENERALLY CAPPED AT 10 KTS AS A RESULT. A SLIGHT PINCH IN THE GRADIENT ON WED AS WEAK LOW PRESSURE DEVELOPS TO THE EAST OF THE FORECAST WATERS. 2 TO 3 FT SEAS WILL BE LOWEST NEAR SHORE AND HIGHEST OFFSHORE...WITH THE GREATEST RANGE OFF THE BRUNSWICK COAST WHERE THE FLOW WILL BE MOST COAST-PERPENDICULAR. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3 AM MONDAY...PRETTY STRONG COLD FRONT SLATED FOR THURSDAY WINDS AHEAD OF ITS PASSAGE PRETTY LIGHT AND HARD TO PIN DOWN ON ACCOUNT OF PRESENCE OF A SURFACE TROUGH. BY LATER IN THE DAY THOUGH NW WINDS START CRANKING UP. SMALL CRAFT ADVISORY APPEARS LIKELY BY FRIDAY IF NOT SOONER ON ACCOUNT OF WINDS. THE NW FETCH MAY KEEP SEAS FROM BUILDING INTO ADVISORY REALM. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR AMZ250- 252. && $$ NEAR TERM...III SHORT TERM...MBB LONG TERM...MBB AVIATION...MDC