398 FXUS62 KILM 141839 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 239 PM EDT SAT APR 14 2012 .SYNOPSIS... SUMMER-LIKE BERMUDA HIGH PRESSURE WILL BRING WARM WEATHER THROUGH TUESDAY. A COLD FRONT WILL BRING RAIN CHANCES LATE TUESDAY INTO WEDNESDAY FOLLOWED BY SEASONABLE LATE WEEK TEMPERATURES. && .NEAR TERM /THROUGH TONIGHT/... AS OF 2 PM SATURDAY...SURFACE HIGH...NOW SOLIDLY OFF THE CAROLINA COAST...AND BUILDING UPPER RIDGE TO REMAIN IN CONTROL OVERNIGHT. DIURNAL CU ALONG WITH CLOUD ASSOCIATED WITH CLOUD COVER ALONG WEAK COASTAL TROUGH OVER SC COUNTIES IS SLOWLY SPREADING NORTH. CLOUD COVER WILL SPREAD OVER SOME OF THE NC COUNTIES LATER THIS AFTERNOON BUT WILL START TO DISSIPATE WITH THE LOSS OF HEATING. AS COASTAL TROUGH MOVES INLAND IT WILL WEAKEN FURTHER...LIMITING CLOUD COVER OVERNIGHT. FORECAST SOUNDINGS AND CROSS SECTIONS DO SHOW AN INCREASE IN MOISTURE ALOFT TONIGHT IN THE FORM OF CIRRUS DROPPING DOWN THE EAST SIDE OF THE UPPER RIDGE. SOUTHERLY FLOW CONTINUES OVERNIGHT WITH 20 KT LOW LEVEL JET HELPING TO KEEP THE BOUNDARY LAYER WELL MIXED. COMBINATION OF WINDS AND INCREASING LOW LEVEL MOISTURE WILL KEEP LOWS IN THE LOW TO MID 50S OVERNIGHT... A FEW DEGREES ABOVE CLIMO. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3 PM SATURDAY...A BROAD MID-LEVEL RIDGE...CENTERED ACROSS FLORIDA AND THE BAHAMAS WILL SUPPRESS THE CHANCES FOR ANY RAINFALL THROUGH THE PERIOD. THIS SAME RIDGE WILL BUILD A WARMER AIR MASS ACROSS THE EASTERN CAROLINAS. AT THE SURFACE...HIGH PRESSURE CENTERED WELL OFFSHORE...WILL BRING A S TO SW FLOW ACROSS THE AREA. THIS WILL RESULT IN MUCH HIGHER DEWPOINTS...MORE TYPICAL OF MID APRIL. A SHALLOW LAYER OF MOISTURE ATOP THE MIXED LAYER WILL RESULT IN AFTERNOON/EVE CUMULUS DEVELOPMENT BOTH DAYS. THESE CLOUDS...WITH BASES 4-7 KFT...WILL LIKELY BE ENHANCED ALONG A PRONOUNCED SEABREEZE WHICH WILL MAKE GOOD INLAND PROGRESS AS HEATING INTENSIFIES INTO AND THROUGH THE AFTERNOON. A WELL MIXED ENVIRONMENT IS EXPECTED BOTH DAYS WITH LATE MORNING THROUGH EARLY EVE WINDS GUSTING TO NEAR 20 MPH. WINDS ALONG AND ON THE MARINE SIDE OF THE SEABREEZE BOUNDARY ARE EXPECTED TO BE A LITTLE HIGHER...GUSTING TO 25 MPH. TEMP PROFILES SUPPORT HIGHS IN THE 80S BOTH SUN AND MON...HIGHEST MON. THE EXCEPTION WILL BE ALONG AND NEAR THE COAST WHERE MARINE INFLUENCES WILL PREVENT TEMPS FROM GETTING OUT OF THE LOWER TO MID 70S...COOLEST ON SUN. MINIMUM TEMPS WILL BE WELL ABOVE NORMAL... UPPER 50S TO LOWER 60S WITH PERHAPS A FEW MID 60S MON NIGHT ALONG THE IMMEDIATE COAST WHERE THE HIGHEST DEWPOINTS WILL RESIDE. && .LONG TERM /TUESDAY THROUGH SATURDAY/... AS OF 3 PM SATURDAY...MID TO UPPER RIDGE WILL BE SLIPPING OFF SHORE AND WEAKENING THROUGH TUESDAY AS H5 TROUGH PUSHES COLD FRONT TOWARDS AREA. LATEST GFS SHOWS COLD FRONT MOVING INTO THE CAROLINAS BY LATE TUES AND REACHING THE COAST BY WED. A DEEP MOIST SW FLOW WILL DEVELOP AHEAD OF FRONT ON TUES. SHOULD SEE BEST CHC OF PCP FURTHER INLAND LATE TUES INTO EARLY WED AND THEN ALONG THE COAST WED BEFORE FRONT MOVES OFF SHORE. PCP WATER VALUES INCREASE UP TO 1.5 INCHES LATE TUES JUST NORTH AND WEST OF CWA...WITH STEERING FLOW FROM THE SW AROUND 15 TO 20 MPH. WILL KEEP BETTER CHC OF PCP INLAND LATE TUES INTO TUES NIGHT. AS FRONT SHIFTS CLOSER TO THE COAST BY WED...A MORE WESTERLY STEERING FLOW SHOULD GUIDE ANY STORMS TOWARD THE COAST BRINGING A GREATER CHC OF PCP FOR COASTAL AREAS ON WED. GFS SHOWS PCP WATER VALUES DECREASING TO LESS THAN AN INCH BY LATE WED AS MID TO UPPER TROUGH PUSHES FRONT OFF SHORE WITH A DEEPER NW FLOW DEVELOPING. THIS DEEPER NW FLOW WILL BRING DRIER AIR INTO AREA LATE WED INTO THURS WITH PCP WATER VALUES DOWN AROUND A HALF INCH. AS RIDGE SHIFTS OFF THE COAST ON TUES THE HEIGHTS WILL BE DECREASING AND 850 TEMPS SHOW A SLIGHT DROP...BUT OVERALL EXPECT ANOTHER WARM DAY WITH TEMPS UP AROUND 80. THE STRONGER WESTERLY COMPONENT TO THE FLOW SHOULD KEEP SEA BREEZE PINNED CLOSER TO THE COAST AND HELP BRING WARMER TEMPS ALONG THE COAST. BY LATE TUES INTO WED EXPECT MORE CLOUD COVER AND GREATER CHC FOR PCP WHICH WILL BRING WARMER TEMPS OVERNIGHT...AROUND 60 WHILE LOWER DAYTIME HIGHS IN THE 70S FOR WED. SOME CAA BEHIND FRONT WILL KEEP TEMPS IN THE 70S IN A COOLER AND DRIER NORTHERLY FLOW ON THURS. WEAK HIGH PRESSURE OVER AREA ON THURS WILL MOVE OFF SHORE BY LATE THURS AND SFC FLOW SHIFTS AROUND WITH A WEAK RETURN FLOW SETTING UP. WHILE THE MID TO UPPER FLOW REMAINS MORE ZONAL OVER THE SOUTHEAST...A NORTHERN STREAM SHORTWAVE WILL PUSH ANOTHER COLD FRONT EAST OVERNIGHT THURS WHICH SHOULD REMAIN JUST NORTH OF AREA. WITH DEEP DRIER W-NW FLOW STILL PRESENT ABOVE THE SURFACE...NOT EXPECTING MUCH IN TERMS OF WEATHER. A DEEPER RETURN FLOW WILL SET UP FRI THROUGH SAT AHEAD OF NEXT SUBSTANTIAL SYSTEM WHICH SHOULD MOVE THROUGH AREA FROM THE NW OVER THE WEEKEND. TEMPS WILL WARM UP FRI AND SAT AHEAD OF THIS SYSTEM. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... AS OF 18Z...HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH THE FORECAST PERIOD. HIGH PRESSURE WILL SHIFT OFFSHORE ALLOWING FOR SOUTHWEST FLOW TO RETURN. THE GRADIENT INCREASES WITH GUSTS TO 20 KTS POSSIBLE THROUGH SUNSET. WINDS WILL DIMINISH SOMEWHAT THIS EVENING...BUT SHOULD STAY ABOVE 5 KTS FOR MOST OF THE NIGHT... LITTLE OR NO FOG EXPECTED. SUNDAY...ANOTHER EXCELLENT AVIATION DAY WITH LIGHT WINDS...POSSIBLE HIGH STRATA CU CEILING BASED ON TIME HEIGHT. EXTENDED OUTLOOK...MORNING FOG POSSIBLE MONDAY AND TUESDAY. SCATTERED SHOWERS POSSIBLE WEDNESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 2 PM SATURDAY...LIGHT SOUTHERLY FLOW OVER THE WATERS THIS AFTERNOON...UNDER 10 KT...WILL INCREASE TONIGHT AND VEER TO SOUTHWEST AS CENTER OF HIGH PRESSURE MOVES FARTHER OFF THE COAST. ONLY A SLIGHT INCREASE IN THE GRADIENT IS EXPECTED WITH WINDS EXPECTED TO REMAIN AT OR BELOW 15 KT THROUGH THE END OF THE PERIOD. SEAS 1 TO 2 FT THIS AFTERNOON BUILD TO 2 TO 3 FT OVERNIGHT. THE MAIN COMPONENT WILL BE A SOUTHWEST WIND WAVE ALONG WITH A SMALL EASTERLY SWELL. SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 3 PM SATURDAY...HIGH PRESSURE ANCHORED OFFSHORE THROUGH THE PERIOD WILL KEEP SW WINDS ACROSS THE WATERS. A PRONOUNCED SEABREEZE WILL DEVELOP DURING THE LATE MORNING...BACKING WINDS TO SSW NEAR SHORE INTO THE EVE. WINDS WILL BE HIGHEST ACROSS THE NEAR SHORE WATERS WHERE THE THERMAL GRADIENT WILL BE TIGHTEST. WINDS UP TO 15 TO 20 KT ARE EXPECTED DURING THE AFTERNOON AND EVE HOURS. SEAS WILL BE A FUNCTION OF A PERSISTENT SW TO SSW WIND AND A WEAK 8 TO 9 SECOND SE SWELL. WILL CAP HEIGHTS AT 4 FT...ALTHOUGH THERE MAY BE SOME 5 FT SEAS JUST BEYOND 20 NM. LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 3 PM SATURDAY...A SOUTHWESTERLY RETURN FLOW AROUND HIGH PRESSURE LOCATED OFF SHORE ON TUES WILL BEGIN TO VEER AROUND LATE DAY AS A COLD FRONT APPROACHES FROM THE NORTHWEST. NOT EXPECTING GRADIENT TO TIGHTEN TOO MUCH AHEAD OF FRONT AND THEREFORE WILL MAINTAIN A MODERATE S-SW FLOW UP TO 15 KTS ON TUES. COLD FRONT SHOULD REACH THE COAST WED MORNING MOVING THROUGH BY WED AFTN. WINDS WILL VEER AROUND TO THE N-NW BEHIND FRONT WED AND WILL CONTINUE TO VEER AROUND TO THE NE BY WED NIGHT. BY THURS WINDS WILL BECOME MORE ON SHORE BEFORE A RETURN FLOW SETS UP AS HIGH PRESSURE SHIFTS OFF SHORE. WITH FLOW REMAINING 10 TO 15 KTS THE SEAS WILL NOT BUILD TOO MUCH. EXPECT SEAS TO REMAIN 3 FT OR LESS THROUGH THE PERIOD WITH SOME 4 FTERS IN OUTER WATERS IN SLIGHT SURGE BEHIND FRONT WED EVENING. WNA SHOWING A LONGER PERIOD UP TO 12 SECOND NE SWELL MOVING INTO WATERS ON THURS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...III SHORT TERM...RJD LONG TERM...RGZ AVIATION...III/DL