000 AGXX40 KNHC 140539 MIMATS MARINE WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 140 AM EDT WED MAY 14 2008 MARINE WEATHER DISCUSSION FOR GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO...BUOY...CMAN...AND SHIP REPORTS ACROSS THE GULF EARLY THIS MORNING SHOW A STEADY E TO SE WIND FLOW WEST OF 85W. EARLIER QUIKSCAT DATA CONFIRMS THIS AND REVEALED THE HIGHEST CONCENTRATION OF SE 20 KT WINDS BETWEEN 87W AND 94W...WITH A SMATTERING OF 20 KT WINDS ALSO OVER THE NW GULF DIRECTLY OFFSHORE THE TX COAST. SEAS RANGE FROM 2 TO 3 FT E OF 85W... 3 TO 4 FT BETWEEN 85W AND 90W...AND 4 TO 7 FT W OF 90W N OF 22N IN SE WIND WAVES WITH A DOMINANT PERIOD OF AROUND 6 SEC. QUIKSCAT DATA ALSO INDICATED AN ENHANCED NE TO E WIND FLOW ALONG AND JUST OFFSHORE THE N COAST OF THE YUCATAN...WITH SPOTTY REPORTS OF 25 KT NOTED WITHIN 60 NM OF THE COAST. WATER VAPOR IMAGERY SHOWS A VIGOROUS CLOSED CYCLONE OVER THE SW CONUS...WITH STRONG ANTICYCLONIC FLOW UPSTREAM READY TO POUR INTO THE WESTERN STATES. THE STRONG UPSTREAM FLOW SHOULD FORCE PART OF THE SW CYCLONE EJECT INTO THE SOUTHERN PLAINS AND THEN CENTRAL MS VALLEY DURING NEXT 24 HOURS...WHICH SHOULD FORCE A N-S ORIENTED COLD FRONT CURRENTLY ACROSS THE PLAINS TO THE NW GULF COAST THU AFTERNOON. EVEN THOUGH MODEL GUIDANCE HAS SPED UP WITH THE ARRIVAL OF THE FRONT ALONG THE TX COAST SINCE YESTERDAY ...THEY ALL AGREE THAT IT WILL NOT BE UNTIL FRI MORNING THAT THE FRONT PUSHES FAR ENOUGH OFFSHORE FOR AN INCREASING NW TO N FLOW TO BUILD BEHIND IT. THIS MINOR HESITATION SEEMS TIED TO THE PASSAGE OF A RELATED NORTHERN STREAM TROUGH PASSING FROM THE MIDWEST INTO THE EAST THU THROUGH FRI. UNTIL THEN...THE STEADY E TO SE FLOW NOW OVER THE GULF SHOULD VEER MORE SE TO S...WITH STRONGEST WINDS STILL PRIMARILY W OF 85W. DURING THIS TIMES...SEAS SHOULD BE DOMINATED BY SE WIND WAVES WITH PERIODS OF 5-6 SEC AND SEAS POSSIBLY AS HIGH AS 8 FT IN A FEW LOCATIONS OVER THE CENTRAL AND NW GULF. PRIOR TO THE FRONT SWEEPING THROUGH THE NORTHERN GULF FRI AND SAT...S TO SW WINDS AHEAD OF IT ARE FORECAST TO WEAKEN TO 10 TO 15 KT...WHICH SHOULD CAUSE SEAS TO SUBSIDE TO 3 TO 5 FT...EXCEPT LOCALLY TO 6 FT DIRECTLY AHEAD OF THE FRONT. BY FRI AFTERNOON...MODELS SHOW THE FRONT FROM THE FL PANHANDLE TO NEAR TAMPICO MX...ACCOMPANIED BY A BRISK N TO NE WIND OF 20 TO 25 KT. HOWEVER...GUIDANCE FROM THE LAST FEW DAYS AND IN THE LATEST RUNS DIMINISH WINDS TO 15 KT BY SAT NIGHT...AS THE MAIN DYNAMICS SLIDE QUICKLY NE OF THE AREA. THE SHORT DURATION OF STRONGER WINDS AND THE NARROW FETCH SHOULD ONLY RESULT IN SEAS BUILDING TO 5 TO POSSIBLY 8 FT IN SHORT PERIOD NE WIND WAVES BEFORE SUBSIDING AS SOON AS FRI NIGHT/EARLY SAT. GOING INTO THE WEEKEND...MODELS CARVE OUT A DEEP CLOSED CYCLONE OVER NEW ENGLAND ALONG WITH AN ASSOCIATED LONGWAVE TROUGH NEAR THE U.S. EAST COAST. THIS SHOULD CAUSE THE FRONT TO SWEEP SE TO A PSTN FROM NEAR TAMPA TO THE WESTERN BAY OF CAMPECHE SAT MORNING AND THEN SLOW CONSIDERABLY AND ESSENTIALLY STALL AS IT REACHES FROM SOUTH FL TO NEAR 24N90W TO 19N95W SUN MORNING. A N TO NE WIND OF 10 TO 15 KT BEHIND IT AND SEAS OF 3 TO 5 FT SHOULD DIMINISH FURTHER INTO SUN AS THE WINDS BACK TO W OR NW. SEAS BY THEN ARE FORECAST TO SUBSIDE TO 1 TO 3 FT SUN. S OF THE FRONT A SW TO W FLOW OF 5 TO 10 KT SHOULD PREVAIL E OF 87W...WITH SEAS OF 1 TO 2 FT. W OF 87W...E TO SE WINDS OF 10 TO 15 KT ARE LIKELY WITH SEAS OF 2 TO 4 FT. SW ATLC...THE DEEP STORM SYSTEM NEAR THE MID-ATLANTIC COAST EARLY THIS WEEK HAS NOW MOVED INTO THE CENTRAL ATLC AND IS GRADUALLY WINDING DOWN. THE ASSOCIATED COLD FRONT HAS PUSHED FARTHER SE AND NOW EXTENDS FROM 31N58W TO 25N65W TO SE CUBA. ALTHOUGH THE INTENSE W-NW FLOW OF UP TO 30 KT W OF THE FRONT HAS DECREASED...EARLIER QUIKSCAT AND SHIP REPORTS STILL SHOW 20 TO 25 KT WINDS N OF 27N W OF THE FRONT TO ABOUT 76W...HIGHEST TO THE N. THE LONG DURATION OF THESE WINDS AND THE RATHER WIDE FETCH HAS LED TO A VERY SIGNIFICANT AND RARE SWELL EVENT FOR MAY OFFSHORE THE U.S. EAST COAST....WITH SEAS OF 10 TO 17 FT OVER THE AREA DESCRIBED ABOVE. IN FACT...BUOY 41047 NEAR 27.5N71.5W REPORTS NW WINDS OF 20 KT...WITH SEAS OF 14 FT EARLIER NOW SUBSIDING TO 12 FT IN LONG 13 SEC PERIOD WAVES. JUST N OF THE AREA...BUOY 41048 HAS EVEN HIGHER SEAS OF 16 FT WITH SUSTAINED 25 KT WINDS. OVER THE NEXT 24 TO 36 HOURS...EXPECT THE FRONT TO SLOW BUT CONTINUE PUSHING SE...WITH THE FRONT EXTENDING FROM 24N65W TO HISPANIOLA THIS AFTERNOON AND FROM 21N65W TO N OF THE MONA PASSAGE THU AFTERNOON. THE COVERAGE AND INTENSITY OF THE DEEP-LAYERED CYCLONIC FLOW W OF THE FRONT SHOULD GRADUALLY DIMINISH...AS A WEAK SURFACE RIDGE BUILDS SE FROM THE SE U.S. COAST. STILL THOUGH...THE MAIN THEME WILL BE SIGNIFICANT LONG PERIOD N TO NE SWELL PROPAGATING INTO THE REGION...WITH SEAS ONLY GRADUALLY SUBSIDING FROM NOW UNTIL FRI. SOME OF THE NE SWELL TOO WILL PUSH THROUGH THE GAPS AND PASSES IN THE BAHAMAS AND AGAINST THE GULF STREAM AND MAKE FOR CHOPPY TO ROUGH SEAS...WITH SEAS POSSIBLY APPROACHING 6 TO 7 FT W OF THE NW BAHAMAS IN UNPROTECTED AREAS. NO SOONER WILL THE SWELL FROM THIS EVENT BE SUBSIDING THAT THE NEXT COLD FRONT WILL ARRIVE OVER THE SERN STATES. THE FRONT SHOULD ARRIVE IN RESPONSE TO THE DEEP LONGWAVE TROUGH FORECAST TO FORM ALONG THE U.S. EAST COAST LATE THIS WEEK INTO THE WEEKEND. PRECEDING THE FRONT...BRISK S TO SW WINDS OF 20 TO 25 KT SHOULD BEGIN DEVELOPING INITIALLY N OF 29N W OF 76W THU EVENING AND THEN SPREADING MUCH FARTHER E FRI AFTERNOON THROUGH SAT MORNING. ALREADY CHURNED SEAS WILL REBUILD TO 7 TO 11 FT IN ADVANCE OF THE FRONT IN SW WIND WAVES. AS HAS BEEN THE CASE THE LAST SEVERAL NIGHTS...THE 00Z GFS IS A HAIR FASTER THAN THE REMAINDER OF THE GUIDANCE WITH THE FRONT FORECAST TO MOVE OFF THE NE FL COAST LATE FRI-EARLY SAT. MINOR CHANGES WILL BE MADE TO THIS PACKAGE TO ADJUST FOR THE SLIGHTLY SLOWER TIMING. W OF THE FRONT EARLY SAT...W TO NW WINDS OF 20 TO 25 KT WILL QUICKLY DIMINISH TO 10 TO 15 KT BY SAT AFTERNOON...WITH SEAS PEAKING FROM 5 TO 8 FT W OF THE FRONT SAT MORNING OR EARLY AFTERNOON AND THEN SUBSIDING. BY SUN...A DEEP-LAYERED CYCLONIC FLOW ALONG THE U.S. EAST COAST WILL REMAIN...WITH WINDS APPROACHING 20 KT POSSIBLE ALONG THE NORTHERN BORDER AND 10 TO 15 KT ELSEWHERE. THIS SHOULD RESULT IN A STRONG GRADIENT OF SEAS FROM 3 TO 4 FT OFFSHORE THE FL E COAST TO 6 TO 12 FT W OF THE FRONT OVER THE NORTHERN WATERS IN FRESH SHORT PERIOD W TO NW WIND WAVES. CARIBBEAN AND N TROPICAL ATLC...SUBTROPICAL RIDGING OVER THE EASTERN CARIBBEAN HAS RETREATED INTO THE TROPICAL ATLC...AS LOW PRES DOMINATES MUCH OF THE CENTRAL AND WESTERN ATLC. AS A RESULT...TRADES ARE CLOSE TO OR PERHAPS SLIGHTLY BELOW CLIMATOLOGICAL AVERAGES OVER THE CARIBBEAN BASIN. LATEST SCATTEROMETER DATA REVEAL A SIMILAR PATTERN OBSERVED THE LAST FEW NIGHTS...WITH STRONGEST TRADES OF 20 KT LOCALIZED TO S OF 14N BETWEEN ABOUT 65W AND 77W AND LOCALLY 25 KT WINDS DIRECTLY OFFSHORE THE COAST OF COLOMBIA. SEAS ACROSS THIS AREA RANGE FROM 6 TO 8 FT IN SHORT PERIOD NE TO E WIND WAVES. ELSEWHERE... LIGHTER E TO SE TRADES OF 10 TO 15 KT PREVAIL EXCEPT IN THE GULF OF HONDURAS WHERE E TO SE 20 TO 25 KT CONTINUE. SEAS THERE ARE UP TO AT LEAST 8 FT LOCALLY. LITTLE CHANGE TO THIS PATTERN IS EXPECTED THE NEXT FEW DAYS ...THOUGH HIGH PRESSURE BUILDING SE OFF THE SE U.S. COAST BEHIND A COLD FRONT SHOULD SPARK A ROUND OF ENHANCED NE WINDS THROUGH THE WINDWARD PASSAGE BEGINNING TONIGHT THROUGH THU. MODEL GUIDANCE HAS BEEN SLOW TO RESPOND TO THE FAVORABLE NE WIND FLOW FORECAST...AND CHANGES WILL BE MADE TO REFLECT A LIKELY 2O KT TO 25 KT NE WIND THOUGH THE AREA OVER THIS TIME FRAME. OTHERWISE ...A WELL-DEFINED LONG PERIOD NW TO N SWELL OVER THE SW ATLC SHOULD BEGINNING ARRIVING OVER THE NORTHERN CARIBBEAN TODAY THROUGH EARLY THIS WEEKEND BEFORE GRADUALLY SUBSIDING. SEAS COULD POSSIBLY BUILD TO AS HIGH AS 8-9 FT ALONG THE NORTHERN COASTS OF PUERTO RICO AND HISPANIOLA...WITH SOME OF THE SWELL BLEEDING THROUGH THE ATLC PASSAGES AND INTO THE EASTERN CARIBBEAN. WARNINGS... ATLC... NONE. CARIBBEAN... NONE. GULF OF MEXICO... NONE. .FORECASTER KIMBERLAIN. TROPICAL PREDICTION CENTER.