000 FXUS62 KILM 121921 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 321 PM EDT WED MAR 12 2008 .SYNOPSIS... HIGH PRESSURE WILL BUILD OVER THE AREA AND WILL SLIDE OFF THE SOUTHEAST UNITED STATES COAST THURSDAY AND FRIDAY. A COLD FRONT WILL MOVE THROUGH SATURDAY. HIGH PRESSURE BUILDS IN SUNDAY THROUGH TUESDAY WITH ANOTHER COLD FRONT MOVING ACROSS THE REGION ON WEDNESDAY. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... AS OF 3 PM WEDNESDAY...PLENTY OF DRY AIR IN PLACE THIS AFTERNOON WITH DEWPOINT TEMPS RUNNING A FEW DEGREES BELOW GUIDANCE...IN THE MID TO UPPER 20S. LOW TO MID FLOW BACKS AROUND TO THE WEST THROUGH TONIGHT WITH SLIGHT INCREASE IN MOISTURE AROUND H85...BUT OVERALL EXPECT CLEAR SKIES AND CALM WINDS. RIDGE AXIS MOVES SLOWLY EAST OVER LOCAL AREA OVERNIGHT. WILL HAVE IDEAL RADIATIONAL COOLING CONDITIONS AS WINDS DROP TO NEAR CALM AFTER SUNSET AND SKIES REMAIN CLEAR...ALLOWING TEMPS TO DROP DOWN TO AROUND 40 INLAND AND MID 40S ALONG THE COAST. LATEST GUIDANCE GOING SLIGHTLY LOWER FOR MIN TEMPS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... AS OF 3 PM WEDNESDAY...FRONTAL BOUNDARY EXPECTED TO STALL AND DISSIPATE TO THE NORTH OF THE COUNTY WARNING AREA AS HIGH PRESSURE REMAINS IN CONTROL THURSDAY INTO LATE FRIDAY. MODELS INDICATE A 130 KNOT JET IN THE ZONAL FLOW AT 300 MB APPROACHING TEXAS FRIDAY MORNING. THIS JET IN NEARLY ZONAL FLOW WILL HELP INITIATE A STRONG LOW ON THE LEE SIDE OF THE ROCKIES WHICH WILL BEGIN PROPAGATING TOWARD THE CAROLINAS. EXPECT TO SEE HIGH CLOUDINESS FROM THIS SYSTEM AND A LEADING LOW PRESSURE AREA WHICH MOVES WELL TO THE NORTH AND WEST OF THE REGION ON FRIDAY. FOR THIS TIME PERIOD THE FORECAST WILL SHOW INCREASING CLOUD COVER BY FRIDAY AFTERNOON AND INCREASING CHANCES OF LIGHT SHOWER OF 20 TO 30 PERCENT AFTER MIDNIGHT SATURDAY MORNING. WILL FOLLOW STATISTICAL GUIDANCE WHICH SHOWS LOWS REBOUNDING INTO THE LOWER 50S BY THURSDAY NIGHT AND HIGHS IN THE LOWER TO MID 70S EACH DAY WITH A HINT OF UPPER 60S ALONG THE BEACHES. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 3 PM WEDNESDAY...MAIN PLAYER IN THE EXTENDED IS A PROGRESSIVE SOUTHERN STREAM SYSTEM...WHICH WILL PUSH A COLD FRONT THROUGH THE AREA ON SATURDAY. THIS WILL BE OUR ONE REAL SHOT AT PRECIP...BUT IN SUCH A PROGRESSIVE PATTERN THE QPF WILL NOT BE THAT IMPRESSIVE. STRONG HIGH PRESSURE RIDGING IN FROM THE NORTH SUN-MON...RESULTING IN DRY CONDITIONS AND TEMPS ABOUT 2 CATEGORIES BELOW NORMAL. HIGH PRESSURE SLIPS OFFSHORE BY TUESDAY...ALLOWING TEMPS TO MODERATE TOWARD THE END OF THE PERIOD. COLD FRONT PROGGED TO MOVE INTO THE CAROLINAS ON WEDNESDAY...BUT GIVEN THE DIFFICULTIES OF TIMING THIS FAR OUT...POPS WILL BE KEPT IN THE SILENT 20 RANGE FOR NOW. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... MODEL SOUNDINGS SHOW A VERY DEEP DRY NW FLOW THRU THE END OF THE TAF PERIOD. SEE NO CIG OR VSBY ISSUES THRU THEN. WINDS GO CALM TONIGHT AFTER SUNSET AS HIGH PRESSURE RIDGES NORTHEAST OUT OF THE GULF. TEMPERATURE DEWPOINT SPREAD SEEMS LARGE ENOUGH TO PREVENT FORMATION OF FOG OVERNIGHT...HOWEVER GIVEN EXCELLENT RADIATIONAL COOLING FOG IS POSSIBLE. LOWER CIGS POSSIBLE SATURDAY AS RAIN CHANCES INCREASE WITH APPROACH AND PASSAGE OF A COLD FRONT. DOES NOT LOOK LIKE A BIG RAINMAKER...BUT TEMPO DECREASES IN VSBY COULD RESULT IN SHOWERS. && .MARINE... NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 3 PM WEDNESDAY...FLOW WILL BACK AROUND SLIGHTLY FROM THE NW TO THE W-SW THROUGH TONIGHT...BUT WILL REMAIN VERY LIGHT AS RIDGE AXIS MOVES OVERHEAD. SEAS WILL DECLINE AS A RESULT...TO AROUND 2 FT OR LESS. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 PM WEDNESDAY...HIGH PRESSURE RIDGE WILL MOVE ACROSS THE WATERS FROM 12 UTC THURSDAY AND SHIFT EAST OF THE WATERS BY 06 UTC FRIDAY AS LOW PRESSURE OVER OHIO VALLEY TO NORTH TEXAS SHIFTS EASTWARDS. THE PERIOD WILL START OFF WITH LIGHT WINDS AND AS GRADIENT INCREASES OVER THE WATERS ON FRIDAY WIND AND SEAS ARE EXPECTED TO APPROACH SMALL CRAFT. BUT AT THIS TIME BELIEVE CONDITIONS WILL FALL JUST SHORT OF SMALL CRAFT OVERNIGHT FRIDAY INTO SATURDAY MORNING. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 PM WEDNESDAY...THE MAIN QUESTION FOR SATURDAY IS HOW MUCH THE WINDS CRANK UP AHEAD OF THE LOW AND ASSOCIATED COLD FRONT. FOR NOW WILL BRING SPEEDS UP TO 20-25 KT...LARGELY LIMITED BY MIXING. COULD BRIEFLY SEE 30 KT IF THE 60 KT LLJ MATERIALIZES...BUT WILL LET LATER SHIFTS TRY TO NAIL THAT DOWN. DURATION OF THE STRONGER SSW WINDS IS SUFFICIENT TO GET 6-7 FT SEAS INTO OUR OUTER WATERS...BUT THAT MAY NEED TO BE BEEFED UP IF FORECAST WIND SPEEDS ARE INCREASED. WILL GO FOR FROPA SAT NIGHT...WITH 15-20 KT BEHIND THE FRONT FOR MOST OF THE REMAINDER OF THE FORECAST PERIOD. GENERALLY NW-N TRAJECTORY WILL KNOCK SEAS DOWN...MAINLY LIMITED TO 2-4 FT IN THE COASTAL WATERS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RGZ SHORT TERM...DRH LONG TERM...RAS AVIATION...EH