000 AGXX40 KNHC 130540 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 145 AM EDT TUE MAY 13 2008 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO...THE WESTERN END OF A COLD FRONT PUSHING SE THROUGH THE SW ATLC HAS BECOMES STATIONARY OVER THE EXTREME SE GULF EARLY THIS MORNING...WITH A POSITION FROM THE SOUTHERN FLORIDA STRAITS TO 25N87W. LIGHT ANTICYCLONIC WINDS ARE EVIDENT N OF THE WEAK BOUNDARY...PER LATEST BUOY AND SHIP REPORTS...WITH SEAS RANGING FROM 2 TO 4 FT OF 90W. ALREADY THOUGH...SHORTWAVE RIDGING ALONG THE MS RIVER VALLEY IS ADVANCING E IN RESPONSE TO THE NEXT SHORTWAVE TROUGH ALREADY DIGGING INTO THE FOUR CORNERS AREA. THIS PATTERN FAVORS LOW PRESSURE FORMING OVER THE SOUTHERN AND CENTRAL PLAINS...WHICH HAS LED TO A SLOWLY INCREASING RETURN FLOW GENERALLY W OF 90W. BUOY AND CMAN REPORTS CONFIRM THIS ...WITH SE 15 TO 20 KT WINDS NOTED W OF 90W AND SEAS 2 TO 4 FT S OF 25N AND 4 TO 6 FT N OF 25N. INTERESTINGLY...THE 6 FT SEAS REPORTED AT BUOY 42109 IS 2 FT ABOVE WAVEWATCH GUIDANCE AND SUGGESTS THAT THERE ALREADY BE OTHER SPOTTY 6 FT REPORTS OVER THE NW GULF. OVER THE COURSE OF THIS WEEK...A PIECE OF THE SHORTWAVE NOW DIGGING INTO THE WEST SHOULD SHEAR E AND COMBINE WITH NORTHERN STREAM SHORTWAVE ENERGY MOVING THROUGH THE GREAT LAKES REGION. THE RESULT WILL BE A FAIRLY DEEP LONGWAVE TROUGH FORMING ALONG THE U.S. EAST COAST BY LATE WEEK...WHILE WHAT IS LEFT OF THE WESTERN SHORTWAVE CUTS OFF AND IS TRAPPED UNDERNEATH WEST COAST RIDGING. THE 00Z GFS DEPARTS FROM THE REST OF THE GUIDANCE BY DEVELOPING THE U.S. COAST QUICKER AND BY GIVING IT A BIT MORE AMPLITUDE. THE 12Z ECMWF/18Z NCEP ENS MEAN/00Z CMC CONSENSUS IS INSTEAD PREFERRED...GIVEN THAT THEY ALL KEEP THE MEAN TROUGH AXIS FARTHER W ON FRI. DESPITE THESE TECHNICAL DETAILS...ALL MODELS COME INTO REASONABLY GOOD AGREEMENT BY SAT CONCERNING THE E COAST TROUGH. GIVEN THIS...MARINE INTERESTS CAN EXPECT A FAIRLY STEADY E TO SE WIND FLOW ACROSS THE GULF FOR MUCH OF THIS WEEK...WITH STRONGEST WINDS OF 15 TO 20 KT GENERALLY W OF 85W. THE DURATION OF THESE WINDS SHOULD CAUSE SEAS TO BUILD TO 4 TO 7 FT W OF 85W BY LATE WED...WITH LOWER SEAS OF 3 TO 5 FT FORECAST E OF 85W. WINDS SHOULD THEN VEER MORE SOUTHERLY THU IN ADVANCE OF A COLD FRONT COMING OUT OF THE SOUTHERN PLAINS...WITH THE FRONT EXPECTED TO MOVE OFF THE TX COAST FRI MORNING. THE FRONT SHOULD SWEEP ACROSS MUCH OF THE NORTHERN GULF THE REST OF THE DAY FRI INTO EARLY SAT...FOLLOWED BY AN INITIAL NLY SURGE OF 20 TO PERHAPS 30 KT OVER THE WESTERN GULF. ALTHOUGH THE WINDS WILL BE OF SHORT DURATION...SEAS COULD BUILD TO 6 TO 10 FT OVER THE W GULF BY LATE FRI. FARTHER E...A BRISK NW TO N FLOW OF 15 TO 20 KT SHOULD COVER THE REMAINDER OF THE GULF N OF THE FRONT...BUT THESE WINDS SHOULD QUICKLY VEER N TO NE SAT AND DIMINISH. THUS...PEAK SEAS OF ONLY 3 TO 5 FT WILL GENERALLY BE THE RULE N OF THE BOUNDARY. SOUTH OF THE BOUNDARY...A LIGHT SW TO W FLOW AND 1 TO 3 FT SEAS SHOULD PREVAIL. SW ATLC...A STORM SYSTEM JUST OFF THE MID-ATLC COAST IS SLOWLY MOVING E INTO THE WESTERN ATLC EARLY THIS MORNING. A LARGE ENVELOPE OF DEEP-LAYERED CYCLONIC FLOW SURROUNDS THIS FEATURE ...WITH AN EARLIER QUIKSCAT PASS INDICATING W TO NW FLOW OF 20 TO 30 KT N OF 27N W OF FRONT TO ABOUT 79W. SEAS OF 10 TO 16 FT COVER MUCH OF THIS AREA IN NW SWELL...THOUGH 4 TO 8 FT SEAS ARE BEING REPORTED IMMEDIATELY OFFSHORE THE FL NE COAST. SATELLITE IMAGERY SHOWS A NARROW LINE OF CONVECTIVE CELLS FORMING ALONG THE ATTENDANT COLD FRONT EXTENDING FROM 31N66W TO THE NW BAHAMAS...WITH LITTLE MORE THAN LOW CLOUDS DEFINING THE REST OF THE BOUNDARY EXTENDING THROUGH THE SOUTHERN STRAITS OF FL. WITHIN 600 NM E OF THE FRONT A SW LOW-LEVEL FLOW OF UP TO 30 KT IS OCCURRING...LEADING TO A LARGE AREA OF 8 TO 13 FT SEAS AHEAD OF THE BOUNDARY. SIGNIFICANT LONG PERIOD N TO NE SWELL WILL POUR SOUTHWARD ALONG THE U.S. EAST COAST AND ARRIVE OVER THE BAHAMAS AND EVENTUALLY TO THE NORTHERN CARIBBEAN...AS THE STORM SLOWLY LEAVES THE E COAST OF THE U.S. FROM NOW THROUGH LATE WEEK. PEAK SEAS OVER THE SW ATLC SHOULD OCCUR LATER TODAY THOUGH OVER THE FAR NE...WITH SEAS OF 10 TO 18 FT N OF 27N E OF 75W BY 18Z. GIVEN THE WIDE FETCH OF THESE WINDS AND THE LONG DURATION...THE N TO NE SWELL SHOULD BE QUITE PERSISTENT...EVEN THROUGH LATE WEEK. THUS...EVEN THOUGH WEAK HIGH PRESSURE SHOULD TAKE HOLD BY THU...SEAS OF 8 TO 11 FT IN LONG PERIOD NE SWELL WILL STILL BE COMMON ALL AREAS NE OF THE BAHAMAS. BY FRI...THE NEXT COLD FRONT WILL BE SURGING SEWD THROUGH THE EASTERN STATES...THOUGH NOT AS FAST AS THE 00Z GFS INDICATES. NEVERTHELESS...EXPECT A S TO SW 20 TO 25 KT FLOW TO DEVELOP N OF 28N W OF 74W BY FRI MORNING AND SPREAD E THROUGH THE DAY. SINCE SEAS WILL HAVE LITTLE TIME TO SUBSIDE...EXPECT SEAS TO RAPIDLY REBUILD TO 8 TO 12 FT OVER THE NORTHERN WATERS LATER FRI. ALL MODELS SHOW THE FRONT MOVING OFF THE SE COAST SAT MORNING... FOLLOWED BY AN INITIAL SURGE OF W TO NW 20 KT WINDS. THESE WINDS SHOULD QUICKLY ABATE THOUGH...THOUGH THE STRONGER SW FLOW OF 20 TO 30 KT IN ADVANCE OF THE FRONT SHOULD CONTINUE SPREADING E OVER THE NORTHERN WATERS THROUGH SAT....WITH SEAS OF 8 TO 14 FT. CARIBBEAN AND TROPICAL ATLC...MODERATE TO OCCASIONALLY FRESH TRADES ARE ACTIVE OVER THE CARIBBEAN WATERS EARLY THIS MORNING. AN EVENING QUIKSCAT PASS REVEALED A SIMILAR PATTERN TO THAT OBSERVED YESTERDAY...WITH STRONGEST WINDS OF 20 KT COVERING THE AREA S OF 15N BETWEEN 64W AND 75W AND WEAKER 10 TO 15 KT ELSEWHERE EXCEPT OVER THE GULF OF HONDURAS. LIKE LAST NIGHT TOO...A SUSTAINED E TO SE WIND OF 20 KT IS OCCURRING OVER THAT AREA. THOUGH THERE ARE NO CURRENT SHIP REPORTS OVER THAT AREA...IT IS SUSPECTED THAT SEAS ARE LOCALLY HIGHER OVER THE GULF OF HONDURAS...PERHAPS UP TO 8 FT IN LOCALIZED AREAS. OVER THE NEXT FEW DAYS...AS LOW PRESSURE DOMINATES THE WESTERN ATLC...EXPECT THE WESTERN EDGE OF THE LOW-LEVEL SUBTROPICAL RIDGE TO CONTRACT EASTWARD. THIS SHOULD RESULT IN PERHAPS A BRIEF AND MINOR DIMINUTION TO THE TRADES WED. THEREAFTER...WEAK HIGH PRESSURE BUILDING INTO THE SW ATLC SHOULD REINFORCE THE CURRENT EARLY WEEK PATTERN...KEEPING A MODERATE TO OCCASIONALLY FRESH TRADE WIND FLOW AREA WIDE THROUGH FRI. AS THE HIGH BUILDS SOUTHWARD WED NIGHT INTO THU...A FAVORABLE NE FLOW SHOULD PUSH THROUGH THE WINDWARD PASSAGE AND LED TO SOME FUNNELING OF THE WIND...WITH SPEEDS POSSIBLY APPROACHING 25 KT. GFS GUIDANCE ALSO IS INDICATING AN ENHANCEMENT TO WINDS IN THE GULF OF HONDURAS FOR MUCH OF THE PERIOD...AND THIS WILL BE REFLECTED IN THE OFFSHORE FORECAST. OTHERWISE...THE SOUTHERN END OF THE COLD FRONT CURRENTLY SWEEPING THROUGH THE SW ATLC WILL PUSH THROUGH THE NORTHERN TROPICAL ATLC WATERS THU. WELL-DEFINED LONG PERIOD NW SWELL SHOULD ARRIVE OVER THE NORTHERN CARIBBEAN AND INTO THE TROPICAL ATLC THU THROUGH SAT...WITH SEAS OF 6 TO 8 FT ARRIVING OVER THE AREA N OF 18N. FINALLY...TRADES TO 20 KT SHOULD CONTINUE S OF 12N OVER THE TROPICAL ATLC THROUGH THE PERIOD. WARNINGS... ATLC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. .FORECASTER KIMBERLAIN. TROPICAL PREDICTION CENTER.