000 AGXX40 KNHC 071900 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 250 PM EDT SAT APR 7 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 IS ONCE AGAIN BUILDING OVER THE GULF NOW THAT THE RECENT COLD FRONT HAS MOVED SE OF THE AREA...AND IS CURRENTLY WEAKENING ROM ACROSS NW CUBA TO THE YUCATAN CHANNEL. HOWEVER...A RATHER TIGHT PRES GRADIENT IS PRESENT IN THE ERN PART OF THE GULF ALLOWING FOR NE TO E WINDS OF 15-20 KT PRIMARILY TO THE S OF 27N AS REVEALED BY AN ASCAT PASS FROM JUST PAST 15 UTC THIS MORNING. LATEST AND CURRENT OBSERVATIONS SHOW SEAS OF 3-5 FT OVER MUCH OF THE GULF...WITH THE EXCEPTIONS OF THE FAR NRN WATERS WHERE SEAS ARE LOWER (2-4 FT RANGE) AND IN THE FAR SE PART WHERE SEAS OF 5-6 FT ARE SEEN. SEAS ARE EXPECTED TO CHANGE LITTLE THROUGH SUN. OVER THE FAR SE PART ...PARTICULARLY THE STRAITS OF FLORIDA SEAS ARE FORECAST TO RAISE TO AROUND 8 OR 9 FT TONIGHT INTO SUN AS THE NE WIND FLOW COUNTER INTERACTS WITH THE PREVAILING GULF STREAM CURRENT. AS THE HIGH PRES SHIFTS S AND WEAKENS THROUGH SUN NIGHT...WINDS WEAKEN MOSTLY IN THE ERN PORTION OF THE GULF. LIGHT NE-E WINDS REMAIN ELSEWHERE THROUGH LATE MON. WITH THE HIGH SHIFTING S...THIS WILL ALLOW FOR A WEAK COLD FRONT TO BRUSH THE NRN WATERS MON AND TUE WITH LIGHT WINDS SHIFTING WINDS. HIGH PRES THEN SETTLES IN OVER THE NW PORTION WED AND BECOMES REPLACED BY AN EXPANDING AREA OF STRONGER HIGH PRES FROM THE NW INTO THU WHILE SLIDING EWD. THE COMBINATION OF THE HIGH AND LOW PRES OVER PLAINS SHOULD ALLOW FOR WINDS ACROSS THE WRN GULF TO INCREASE WHILE VEERING AROUND TO THE SE WED AND THU. CARIBBEAN SEA AND TROPICAL ATLC S OF 19N W OF 55W... BUOY OBSERVATIONS FROM THIS MORNING AND EARLY AFTERNOON REVEAL LIGHT TRADES ACROSS THESE AREAS. AN ASCAT PASS FROM JUST PAST 15 UTC THIS MORNING VERIFIED THE LIGHT WIND CONDITIONS. SLIGHTLY HIGHER WINDS...NE TO E IN DIRECTION...ARE NOTED OVER THE FAR SE WATERS OF THE TROPICAL N ATLANTIC. WINDS INCREASE TO 20 KT IN THE FAR NRN PORTION OF THE NW CARIBBEAN LATE SUN NIGHT INTO MON AS GULF OF MEXICO HIGH PRES PRESSES SEWD. THE ASSOCIATED PRES GRADIENT THEN RELAXES LATER MON ALLOWING FOR THE WINDS TO DIMINISH. N SWELLS CONTINUE TO SUBSIDE ACROSS THE TROPICAL N ATLC AS EVIDENT BY OBSERVATIONS FROM BUOYS 41044 AT 22N59W AND 41101 AT 15N56W WHERE COMBINED SEAS ARE 6-7 FT. SEAS ARE FORECAST TO REMAIN RATHER LOW THROUGHOUT THE CARIBBEAN DURING THE PERIOD...WITH RANGES OF 3-4 FT W OF 70W...AND 3-5 FT E OF 70W. IN THE TROPICAL N ATLC SEAS ARE FORECAST TO LOWER TO AROUND 4-6 FT SUN THROUGH MON...BUT BE SHORT-LIVED MAINLY IN THE NRN AND CENTRAL SECTIONS AS A NE SWELL COMPONENT BUILDS SEAS BACK UP TO 7 OR 8 FT THERE WED AND THU AS ERN AND CENTRAL ATLC HIGH PRES BUILDS SW. SOUTHWEST N ATLC FROM 19N TO 31N W OF 55W... THE PRELIMINARY 18 UTC SURFACE ANALYSIS SHOWS THE COLD FRONT NOW HAVING ADVANCED TO ALONG A LINE FROM 26N65W TO E CENTRAL CUBA WHERE IT WEAKENS. SATELLITE IMAGERY SHOWS SCATTERED SHOWERS AND TSTMS RACING EWD OUT AHEAD OF THE FRONT. RECENTLY ARRIVED ASCAT DATA SHOWS NW-N WINDS OF 20-25 KT BEHIND THE FRONT TO NEAR 74W WITH INDICATIONS OF 25-30 KT WINDS IN THE FAR NE PART OF SW N ATLC FORECAST WATERS. HIGH PRES IS BUILDING SEWD IN BEHIND THE FRONT. BUOYS AND SHIPS SHOW LARGE SEAS IN THE N SWELL TRAIN PROPAGATING SW BEHIND THE FRONT. COMBINED SEA HEIGHTS OF 10-13 FT ARE N AND NE OF THE BAHAMAS. SEAS OF 8-10 FT ARE ELSEWHERE... EXCEPT SW OF THE BAHAMAS WHERE SEAS OF 5-7 FT ARE SEEN. THE COLD FRONT WILL WEAKEN AND GRADUALLY STALL ALONG 22N E OF 65W STERN CUBA EARLY TONIGHT...BEFORE STALLING ALONG 22N E OF 65W SUN INTO MON AS RIDGING BUILDS EASTWARD ALONG 29N. SW WINDS WILL BEGIN TO INCREASE OVER THE FAR NORTHERN WATERS LATE MON INTO TUE IN ADVANCE OF THE NEXT COLD FRONT FORECAST TO MOVE INTO THE FAR NW PORTION. WINDS AND SEAS BEHIND THE FRONT WILL DIMINISH INTO MON AS HIGH PRES BUILDS FROM W TO E OVER THE AREA. THE HIGH PRES THEN BEGINS TO SHIFT EWD LATE MON AS A COLD FRONT MOVES OFFSHORE THE SE U.S. AHEAD OF IT SW WINDS INCREASE TO 20 KT OVER THE FAR NORTHERN WATERS INTO TUE. THIS FRONT IS EXPECTED TO REACH FROM ALONG 31N76W TO E CENTRAL FLORIDA TUE MORNING...AND FROM NEAR 31N73W TO STRAITS OF FLORIDA AS A WEAKENING COLD FRONT LATER ON TUE AND INTO WED...THEN FROM 27N65W TO ERN CUBA BY LATE THU PER GENERAL NWP MODEL CONSENSUS. HIGH PRES WILL BUILD SE BEHIND IT ALLOWING FOR NLY FLOW THROUGHOUT...EXCEPT IN THE FAR NRN PORTION WHERE NW-N STRONGER FLOW CAN BE EXPECTED. 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