000 AGXX40 KNHC 091858 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 300 PM EDT MON APR 9 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLC S OF 19N W OF 55W...AND SOUTHWEST NORTH ATLC FROM 19N TO 31N W OF 55W. GULF OF MEXICO... HIGH PRES RIDGING IS PRESENT ACROSS THE NRN PORTION OF THE GULF WHILE A WEAK SURFACE TROUGH MOVING W ABOUT 8 KT IS IDENTIFIED ON BOTH SATELLITE IMAGERY AND ASCAT DATA FROM JUST PAST 16 UTC TO EXTEND FROM 26N91W SE TO THE NE YUCATAN PENINSULA AND TO THE NW CARIBBEAN SEA. SCATTERED SHOWERS ARE ALONG AND WITHIN 120 NM E OF THE TROUGH FROM 24N TO 26N. BOTH BUOY AND SHIP OBSERVATIONS IN THE VICINITY OF THE TROUGH REVEAL A VERY DISTINCT NE TO SE WIND SHIFT FROM NE TO SE ACROSS THE TROUGH. THE ASCAT DATA ALSO SHOWED NE-E WINDS OF 15-20 KT E OF THE TROUGH TO NEAR 85W. ELSEWHERE...WINDS ARE GENERALLY NE-E 10-15 KT W OF THE TROUGH ...NE-E 10-15 KT E OF THE TROUGH...AND NE-NE 5-10 KT ELSEWHERE. CURRENT BUOY OBSERVATIONS ARE REPORTING SEAS OF 3-5 FT OVER MUCH OF THE GULF...WITH THE EXCEPTIONS OF THE FAR NRN WATERS WHERE SEAS ARE 2-3 FT AND IN THE FAR SE PORTION WHERE SEAS OF 5-7 FT ARE SLOW IN SUBSIDING. THE RIDGE WILL WEAKEN SOME THROUGH TONIGHT IN THE NE PORTION OF THE GULF AS A WEAK COLD FRONT BRUSHES THROUGH THOSE WATERS TONIGHT INTO TUE. THE STRONGER PORTION OF THE RIDGE WILL ACT TO SUPPRESS THE SURFACE TROUGH AND WEAKEN IT THROUGH...LEADING TO ITS DISSIPATION IN THE WRN GULF ON TUE. ONCE THE WEAK FRONT CLEARS THE NE GULF EARLY TUE...MODELS HINT THAT ANOTHER WEAK COLD FRONT WILL MOVE SE ACROSS THE EASTERN GULF EARLY WED...THEN QUICKLY EXIT THE AREA LATE WED. THIS FRONT WILL BE FOLLOWED BY STRONGER HIGH PRES THAT BUILDS SEWD ACROSS THE SRN U.S. AND GULF REGION. THIS AREA OF HIGH PRES THEN QUICKLY SHIFTS EWD THROUGH FRI AS LOW PRES DEVELOPS OVER THE PLAINS. THE COMBINATION OF THE HIGH AND LOW PRES OVER THE SRN PLAINS SHOULD ALLOW FOR WINDS ACROSS THE WRN GULF TO VEER AROUND THE SE ON WED INTO SAT WHILE INCREASING IN SPEEDS...TO 20 KT BEGINNING ON THU AND TO POSSIBLY 20-25 KT BY LATE FRI OVER PORTIONS OF THE WRN GULF. SEAS ARE FORECAST TO REMAIN NEAR CURRENT OBSERVED VALUES OVER MUCH OF THE MIDDLE AND WRN GULF THROUGH MUCH OF WED...THEN BEGIN TO BUILD INTO SAT POSSIBLY UP TO 8 FT IN THE WRN GULF PER GENERAL WAVEWATCH MODEL CONSENSUS. CARIBBEAN SEA AND TROPICAL ATLC S OF 19N W OF 55W... BUOY OBSERVATIONS FROM THIS MORNING AND EARLY AFTERNOON REVEAL A CONTINUATION OF VERY LIGHT TRADES ACROSS THOSE WATERS. ASCAT PASSES FROM 1246 UTC AND 1426 UTC THIS MORNING VERIFIED THE LIGHT WIND CONDITIONS. HIGHER NE WINDS OF 20 KT ARE FUNNELING SW THROUGH THE WINDWARD PASSAGE TOWARDS JAMAICA. NE 15-20 KT WINDS ARE N OF 20N BETWEEN THE WINDWARD PASSAGE AND 84W. WITH THE PRES GRADIENT OVER THE NRN CARIBBEAN RELAXING THROUGH TUE MORNING... OBSERVATIONS FROM BUOYS IN THE TROPICAL N ATLC...41044 AT 22N59W AND 41101 AT 15N56W SHOW SEAS IN THE 4-5 FT RANGE...A LOT LOWER THAN IN RECENT DAYS. WINDS AND SEAS ARE FORECAST TO REMAIN ON THE LIGHT/LOW SIDE THROUGHOUT THE CARIBBEAN DURING THE PERIOD AS CURRENT BUOY REPORTS SHOW 2-3 FT. SEAS WILL INCREASE TO 4-5 FT RANGE IN THE FAR ERN CARIBBEAN THROUGH SAT AS A NE SWELLS INTRUDES FROM THE CENTRAL ATLC. OBSERVATIONS FROM BUOYS IN THE TROPICAL N ATLC...41044 AT 22N59W AND 41101 AT 15N56W SHOW SEAS IN THE 4-5 FT RANGE...A LOT LOWER THAN IN RECENT DAYS. THESE SEAS ARE FORECAST TO CHANGE LITTLE THROUGH MOST OF TUE...THEN BUILD TO 7 FT MAINLY IN THE CENTRAL PORTION LATER TUE THROUGH SAT AS NW TO N SWELLS COMBINES WITH NE SWELLS. THIS FORECAST IS LOWER WITH THE EXPECTED SEA HEIGHTS THAN WHAT WAS ANTICIPATED IN EARLIER DAYS AS THE SWELL ENERGY WILL BE DECREASING BEFORE THEIR ARRIVAL INTO THE FORECAST WATERS. SOUTHWEST N ATLC FROM 19N TO 31N W OF 55W... THE PRELIMINARY 18 UTC SURFACE ANALYSIS HAS A STATIONARY FRONT EXTENDING FROM 22N60W SW TO ALONG THE N COAST OF HISPANIOLA WHERE IT BECOMES RATHER DIFFUSE. A 1021 MB HIGH CENTER IS ANALYZED AT 28N68W WITH AN E TO W RIDGE EXTENDING W TO CENTRAL FLORIDA AND E TO 28N65W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE ALONG AND WITHIN 45 NM EITHER SIDE OF THE FRONT. ASCAT DATA FROM 1422 UTC THIS MORNING SHOWED NE 20 KT WINDS NW OF THE FRONT TO 24N AND W TO 75W. LIGHTER NLY WINDS ARE ELSEWHERE ACROSS THE BASIN. SEAS CONTINUE TO GRADUALLY SUBSIDE BEHIND THE FRONT WITH MAXIMUM SEAS OF 8-9 FT NEAR 23N72W....AND SEAS OF 5-7 FT ELSEWHERE ACROSS THE AREA WITH THE EXCEPTION OF 3-5 FT SW OF THE BAHAMAS AND 2-3 FT NW OF THE NW BAHAMAS. THE FRONT WILL EVENTUALLY BECOME DIFFUSE THROUGH WED WITH A REMAINING TROUGH FEATURE IS EXPECTED TO LINGER FROM NEAR THE SE BAHAMAS TO ERN CUBA BY WED AS IT DRIFTS W. A WEAK FRONT WILL BRUSH THE WATERS N OF 30N BETWEEN N FLORIDA AND BERMUDA TONIGHT BEFORE WEAKENING AND LIFTING N. SW WINDS WILL BEGIN TO INCREASE OVER THE FAR NORTHERN WATERS TONIGHT INTO TUE IN ADVANCE OF THE NEXT SLIGHTER STRONGER COLD FRONT FORECAST TO MOVE INTO THE FAR NW PORTION. THE FRONT IS FORECAST TO REACH FROM NEAR 31N73W TO NEAR DAYTONA BEACH FLORIDA BY WED AFTERNOON...THEN FROM 31N62W TO 25N70W AND S FLORIDA BY LATE THU. IT WILL THEN BEGIN TO WEAKEN WHILE BECOMING STATIONARY FROM 22N55W TO HISPANIOLA BY LATE FRI WHILE BECOMING DIFFUSE SIMILARLY TO THE PRESENT ONE. MODELS SUGGEST THAT STRONGER HIGH PRES WILL BUILD IN BEHIND THIS COLD FRONT INDUCING A TIGHT PRES GRADIENT OVER MUCH OF THE SRN WATERS LATE FRI AND SAT ALLOWING FOR NE 20 KT WINDS THERE. NOTE... EFFECTIVE APR 3, 2012 AT 1800 UTC THE OFFSHORE WATERS FORECAST ZONES CHANGED FOR THE CARIBBEAN AND SW N ATLANTIC AND THE GULF OF MEXICO. ISSUANCE TIME FOR THE GULF OF MEXICO OFFSHORE WATERS FORECASTS IS REFERENCED TO THE EASTERN TIME ZONE. FOR DETAILS SEE WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF GRIDDED MARINE OUTPUT IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE (LOWER CASE). GULF OF MEXICO... .NONE. .CARIBBEAN SEA AND TROPICAL N ATLC... .NONE. .SW N ATLC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORECASTER AGUIRRE