000 FXUS62 KILM 241930 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 330 PM EDT SUN MAY 24 2009 .SYNOPSIS... MOIST SOUTHERLY FLOW WILL CONTINUE OVER THE NEXT FEW DAYS AS A LOW PRESSURE SYSTEM TRACKS UP THE MISSISSIPPI VALLEY THROUGH THE CENTRAL STATES. WEAK LOW PRESSURE TRACKING NORTHWARD FROM THE BAHAMAS MAY AFFECT THE THE AREA ON TUESDAY. A COLD FRONT WILL REACH THE CAROLINAS ON SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM SUNDAY...CONVERGENT BANDS OF TROPICALLY DERIVED MOISTURE LINE ROUGHLY WELL WITH LOW AND MID LEVEL OMEGA FIELDS...AS BROAD LOW PRESSURE OVER THE SOUTHERN MS VLY AND AN EXTENSIVE BERMUDA HIGH CIRCULATION INTERACT. THIS IS ALLOWING A RICH FEED OF MOISTURE LADEN AIR TO SWELL NORTHWARD OUT OF THE TROPICS. DIURNAL AFTERNOON HEATING WAS CAUSING THE CONVERGENT FOCUS TO BECOME A BIT MORE DIFFUSE WITH ECHO TRENDS ON RADAR EXHIBITING MORE DISCREET CELLULAR GROWTH. WITH THIS IN MIND...IT SEEMS LIKELY THAT THE MAJORITY OF CONVECTION WILL SHIFT FARTHER INLAND THROUGH THE REMAINDER OF THE AFTERNOON INTO EVENING AS THE SEA BREEZE FRONT ADVANCES NORTHWARD. SOUTH CAROLINA WILL REMAIN THE FAVORED REGION FOR LINGERING SHOWERS AND ISOLATED TSTMS REMAINDER OF THE DAY WHERE LOWER TROPOSPHERE WIND SPEED AND DIRECTIONAL CONVERGENCE REMAIN STRONGER JUST OFFSHORE. ISOLATED SHOWERS HOWEVER WILL STILL POP JUST ABOUT ANYWHERE SINCE EVEN A DECENT OUT FLOW BOUNDARY WILL BE CAPABLE OF POPPING A SHRA. EXPECT A LULL IN PCPN EARLY EVENING ACROSS THE ILM LAND AND SEA ZONES. INCREASING SHOWERS WILL LIKELY DEVELOPE OVER THE SOUTHERN MARINE ZONES AS LOSS OF DAYTIME HEATING/MIXING ALLOWS UNDISTURBED LOW LEVEL CONVERGENCE TO BECOME MORE ORGANIZED OVER THE WATERS FROM CHARLESTON TO NORTH SANTEE RIVER AND WINYAH BAY AREA AFTER MIDNIGHT. ASTRONOMICAL HIGH TIDES WITH NEW MOON AND ONSHORE FLOW WILL CAUSE FAIRLY HIGH RUN-UP OF WATER ONTO THE SAND...EXPANDING THE BEACH BERM CLOSER TO THE DUNES. TIDE GAGE PREDICTIONS AND OBSERVED LEVELS IN THE NEAR TERM REMAIN BELOW ACTION STAGE SO AN ADVISORY DOES NOT APPEAR NECESSARY AT THIS TIME. THIS WILL NEED TO BE MONITORED THROUGH AT LEAST TUESDAY NIGHT THROUGH...AS EACH HIGH TIDE COMES WITHIN A FOOT OF ACTION STAGE...BEFORE THE ASTRONOMICAL TIDES FINALLY WANE. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 PM SUNDAY...UNSETTLED WEATHER TO CONTINUE THROUGH THE PERIOD WITH MOIST SOUTHEASTERLY FLOW AS GULF LOW FINALLY TRACKS UP THE CENTRAL CONUS. HIGH PRESSURE GETS PUSHED FARTHER EAST INTO THE ATLANTIC AS A LOW PUSHES NORTH FROM THE BAHAMAS. GFS KEEPS THIS LOW FARTHER EAST AND MOVES IT MUCH SLOWER WHILE NAM TRACKS WEAK LOW CLOSE TO THE SOUTHEAST COAST AND IT BECOMES AN OPEN WAVE OR TROUGH AFFECTING LOCAL AREA BY MON NIGHT INTO TUES MORNING. EITHER WAY A SOUTHERLY FLOW OF WARM MOIST AIR WILL CONTINUE WITH A SPIKE IN PCP WATER EARLY TUES MORNING UP AROUND 2 INCHES. THEREFORE EXPECT CLOUDS AND SHOWERY WEATHER TO CONTINUE WITH SCATTERED SHOWERS THROUGH MOST OF THE PERIOD AND ISO THUNDER BASICALLY IN AFTERNOON HOURS...BUT WENT WITH MORE WIDESPREAD ACTIVITY TUES. TEMPERATURES JUST BELOW CLIMO DURING THE DAY...AROUND 80 AND SEVERAL DEGREES ABOVE NORMAL AT NIGHT...DUE TO INCREASED CLOUD COVER AND MOIST SOUTHERLY FLOW. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... AS OF 3 PM SUNDAY...THE OVERALL FORECAST PHILOSOPHY FOR THE EXTENDED REMAINS THE SAME WITH A GENERAL UNSETTLED/TROPICAL PATTERN UNTIL LATE IN THE PERIOD WHEN A SHIFT IN THE MID LEVEL PATTERN OCCURS...LEADING TO A DRIER FORECAST. BASICALLY FOLLOWED HPC GUIDANCE FOR THE DETAILS...WHICH ADVERTISES WEDNESDAY AND SATURDAY WITH THE HIGHEST POPS...THE LATTER BEING ASSOCIATED WITH A COLD FRONT WHICH WILL USHER IN THE DRIER WEATHER SUNDAY. UNTIL THEN...ALMOST IMPOSSIBLE TO PINPOINT ANY SMALLER FEATURE TRAVERSING THE SOUTH TO SOUTHEASTERLY TROPICAL FLOW THAT MAY ENHANCE POPS AT ANY TIME. BASICALLY MAINTAINED THE DIURNAL TREND. THE GFS REMAINS THE ODD MODEL OUT IN REGARDS TO THE DETAILS FOR NEXT WEEKEND AS IT CONTINUES TO HOLD ONTO THE MID LEVEL TROUGH CLOSING OFF JUST OFF THE COAST WHILE THE OTHER OPERATIONAL MODELS SHOW A MORE PROGRESSIVE OPEN WAVE. AS WOULD BE EXPECTED WITH THIS TYPE OF PATTERN...NO CHANGE TO TEMPERATURE FORECAST/GUIDANCE. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... SHOWERS...MAINLY OVER THE WESTERN TWO THIRDS OF THE CWA...WILL BLOSSOM THIS AFTERNOON WITH ABUNDANT MOISTURE AND HEATING. THINK THUNDER WILL BE QUITE ISOLATED...DUE TO THE TROPICAL NATURE OF THE ATMOSPHERE...SO NO MENTION IN THE TAFS. COASTAL TERMINALS WILL LIKELY BE SPARED ALSO...WITH THE INHIBITING MARINE LAYER. SHOWERS WILL DIMINISH SOMEWHAT THIS EVENING...HOWEVER ANOTHER SLUG OF MOISTURE IS FORECAST TO COME ONSHORE AFTER MIDNIGHT...WITH SCATTERED TO NUMEROUS SHOWERS EXPECTED...ESPECIALLY FOR THE SOUTHERN COASTAL TERMINALS. CEILINGS WILL LOWER TO IFR AT ALL TERMINALS AFTER 06Z...IN SHOWERS AND JUST PLAIN STRATUS. LIGHT SOUTHEAST WINDS ARE EXPECTED THROUGH THE PERIOD. EXTENDED OUTLOOK THROUGH WEDNESDAY...ISOLATED TO SCATTERED THUNDERSTORMS MONDAY. NUMEROUS SHOWERS AND THUNDERSTORMS TUESDAY...WITH SCATTERED CONVECTION WEDNESDAY AND THURSDAY. CEILINGS WILL LIKELY BE IFR MOST MORNINGS. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM SUNDAY...LIGHT TO MODERATE BUT PERSISTENT/EXTENSIVE FETCH REGION WILL SUSTAIN 3 TO 5 FOOT SEAS ACROSS THE COASTAL WATERS THIS AFTN AND OVERNIGHT...WITH DOMINANT WAVE PERIODS OF 6-7 SECONDS EXPECTED. NEAR SHORE SEA BREEZE IS ALLOWING WAVE ENERGY TO BE A BIT MORE SPREAD OUT IN SHORTER WAVELENGTHS...BUT BEYOND THE NEAR SHORE WATERS...ESE SWELL WAS CLEARLY THE DOMINANT WAVE ENERGY AND THIS SHOULD HOLD INTO DAYBREAK MONDAY. MARINERS SHOULD EXPECT STANDING WAVE ACTION THROUGH EAST FACING INLETS DURING FALLING TIDES AS THE INCOMING SWELL INTERACTS WIT THE OUTGOING WATER FLOW. SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 PM SUNDAY...SOUTHERLY WINDS WILL CONTINUE THROUGH THE SHORT TERM PERIOD AS LOW TRACKS NORTH UP THE MISSISSIPPI VALLEY THROUGH THE CENTRAL CONUS. OVERALL WINDS SHOULD BE S-SE 10 TO 15 KTS..BUT MAY SEE A SPIKE IN WINDS AND SEAS MON NIGHT INTO TUES AS GRADIENT TIGHTENS WITH POSSIBLE LOW OR OPEN WAVE TRACKING UP FROM THE BAHAMAS INTO THE LOCAL COASTAL WATERS. SEAS SHOULD REMAIN IN THE 3 TO 4 FT RANGE MOST OF THE PERIOD BUT MAY PEAK UP NEAR 5 FT OR SO TUES MORNING. LONG TERM /WEDNESDAY THROUGH FRIDAY/... AS OF 3 PM SUNDAY...FOLLOWING THE LEAD OF THE PUBLIC SECTION OF THE FORECAST...NOT A LOT OF CHANGE REGARDING THE EXTENDED COASTAL WATERS FORECAST. A SOUTHEASTERLY FLOW OF 10-15 KNOTS WILL PREVAIL INITIALLY AND CONTINUE THROUGH EARLY THURSDAY. THE FLOW WILL THEN BEGIN TO VEER AS A COLD FRONT APPROACHES FROM THE WEST. SPEEDS WILL PICK UP AS WELL CLOSER TO 15 KNOTS. THIS WILL CONTINUE THROUGH FRIDAY AS THE FRONT INCHES CLOSER. WITH THE CONSISTENCY OF THE FLOW...SEAS WILL BE PEGGED AT A RANGE OF 2-4 FEET. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RGZ NEAR TERM...MJC SHORT TERM...RGZ LONG TERM...SHK AVIATION...DL