000 AGXX40 KNHC 080757 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 357 AM EDT SUN APR 8 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... RIDGING EXTENDS N OF THE AREA FROM A 1021 MB HIGH PRES CENTER OFF THE CAROLINAS WESTWARD THROUGH THE LOWER MISSISSIPPI VALLEY. SHIP AND BUOY OBSERVATIONS ALONG WITH SCATTEROMETER DATA INDICATE 20 TO 25 KT EASTERLY WINDS THROUGH THE STRAITS OF FLORIDA AND INTO THE FAR SE GULF. 15 TO 20 KT NE TO E WINDS ARE ALSO NOTED IN THE FAR SW GULF OFF THE WEST COAST OF YUCATAN. SHIP C6VG7 INDICATED SEAS WERE UP TO 7 FT IN THE STRAITS OF FLORIDA THIS PAST EVENING. THE RIDGING WILL WEAKEN TODAY AS A WEAK COLD FRONT CURRENTLY OVER THE MISSISSIPPI VALLEY SAGS SE AND REACHES FROM THE CAROLINAS TO SE TEXAS BY LATE TODAY...ALLOWING THE WINDS AND SEAS OVER THE SOUTHERN GULF TO DIMINISH. THE FRONT WILL NOT APPRECIABLY PENETRATE INTO THE NORTHERN GULF AND MERELY SLIDE EAST AND WEAKEN THROUGH TONIGHT. A FAIRLY STATIC UPPER PATTERN SETS UP TODAY THROUGH EARLY NEXT WEEK WITH A MID TO UPPER LONG WAVE TROUGH OVER THE NE UNITED STATES. WEAK SHORT WAVE TROUGHS WILL MIGRATE ACROSS THE SE STATES IN THE NW FLOW ALOFT...WEAKENING THE SURFACE RIDGE AND ALLOW LIGHT TO MODERATE WINDS OVER THE GULF TO PREVAIL MON THROUGH MID WEEK. THE PATTERN BECOMES A LITTLE MORE AMPLIFIED BY THU...ALLOWING RIDGING OVER THE CENTRAL UNITED STATES TO BUILD AND STRENGTHENING A SURFACE RIDGE FROM THE OHIO VALLEY THROUGH THE CENTRAL GULF. THIS WILL ALLOW SE RETURN FLOW TO INCREASE OVER THE WESTERN GULF BY THU. CARIBBEAN SEA AND TROPICAL ATLC S OF 19N W OF 55W... BUOY OBSERVATIONS AND SCATTEROMETER DATA FROM THE PAST 12 HOURS REVEAL LIGHT TO MODERATE TRADES FROM 55W TO ACROSS THE CARIBBEAN. BUOY AND ALTIMETER DATA INDICATE SEAS AROUND 3 TO 5 FT MOST EVERYWHERE EXCEPT TO AS HIGH AS 6 FT IN THE ATLC WATERS E OF THE WINDWARDS WHERE DECAYING N SWELL IS STILL PROPAGATING. THE STALLED TRAILING END OF A WEAK FRONT IS DRAPED FROM THE WINDWARD PASSAGE TO THE SOUTH OF EASTERN CUBA WILL DISSIPATE THROUGH TODAY. HIGH PRES BUILDING N OF THE BAHAMAS BEHIND THE FRONT WILL ALLOW A SURGE OF 20 KT NE WINDS OVER THE SOUTHERN BAHAMAS WILL BRIEFLY PUSH INTO THE WINDWARD PASSAGE AND NW CARIBBEAN IN THE LEE OF CUBA LATE TODAY AND OVERNIGHT...DIMINISHING BY EARLY MON. THE SAME HIGH PRES WILL DRIFT EAST IN TO THE CENTRAL ATLC TUE INTO WED. THIS WILL TIGHTEN GRADIENT OVER THE TROPICS S OF THE RIDGE. GFS AND ECMWF ARE IN CLOSE AGREEMENT SHOWING E WINDS ACROSS THE TROPICAL ATLC WATERS W OF 55W TO INCREASE TO 20 KT WED INTO THU WITH SEAS INCREASING TO 8 FT BY LATE THU IN FRESH NE SWELL. SOUTHWEST N ATLC FROM 19N TO 31N W OF 55W... A COLD FRONT EXTENDS FROM 31N57W TO THE WINDWARD PASSAGE. RIDGING IS STARTING TO BUILD BEHIND THE FRONT FROM THE SE UNITED STATES TO ALONG 29N. BUOYS AND SCATTEROMETER DATA INDICATE NORTHERLY WINDS THAT WERE 20 KT 12 HOURS AGO HAVE DIMINISHED TO 10 TO 15 KT FOR THE MOST PART N OF 25N. S OF 25N WINDS ARE NE AT 20 KT. THROUGH TONIGHT...A 1021 HIGH PRES CENTER OVER THE CAROLINAS WILL DRIFT E ALONG 29N...ALLOWING S TO SW RETURN FLOW OFF THE NE FLORIDA COAST AND N OF THE BAHAMAS BY TONIGHT. THE AREA OF FRESH NE FLOW WILL CONTRACT TO MAINLY S OF 22N. THE MID TO UPPER PATTERN OVER THE EASTERN SEABOARD AND WESTERN ATLC DOES NOT CHANGE MUCH OVER THE NEXT SEVERAL DAYS. A VERY BROAD MID TO UPPER TROUGH EXTENDS FROM LOW PRES ANCHORED OFF NEW ENGLAND. A SERIES OF WEAK SHORT WAVE TROUGHS ROUND THE BASE OF THE MID/UPPER TROUGH THROUGH MID WEEK. THE FIRST OF THESE WILL PUSH A WEAK COLD FRONT OFF THE NE FLORIDA COAST BY EARLY MON. WEAKENING UPPER SUPPORT AT THE BASE OF THE TROUGH WILL NOT ALLOW THIS FRONT TO PENETRATE FURTHER TO THE SOUTH AND INSTEAD EASE EASTWARD THROUGH LATE MON AS IT DISSIPATES. SURFACE WINDS WILL BE MORE SW N OF 29N AHEAD OF THE WEAKENING FRONT AND A SUBSEQUENT TROUGH. A MORE SUBSTANTIAL FRONT WILL EMERGE OFF THE CAROLINAS BY LATE TUE...REACHING FROM 31N75W TO NE FLORIDA BY EARLY WED...FROM 31N66W TO THE NORTHERN BAHAMAS BY EARLY THU...AND FROM 31N60W TO THE SOUTHERN BAHAMAS BY THU NIGHT. THE FRONT WILL BE PRECEDED BY SW FLOW TO 20 KT...AND FOLLOWED BY NW FLOW TO 20 KT WED...DIMINISHING WED NIGHT AS THE FRONT WEAKENS. 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 CHRISTENSEN