000 AGXX40 KNHC 081854 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 250 PM EDT SUN APR 8 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... A 1025 MB HIGH CENTER IS LOCATED OVER SE GEORGIA WITH ASSOCIATED RIDGING OVER MUCH OF THE NRN AND CENTRAL WATERS. A TROUGH FEATURE IS IDENTIFIED TO BE ALONG 86W FROM 23N TO 28N MOVING W ABOUT 5-10 KT. SATELLITE IMAGERY FROM THIS MORNING AND EARLY AFTERNOON HIGHLIGHTED SMALL CLUMPS OF SCATTERED SHOWERS WITHIN 90-120 NM OF THE TROUGH. BOTH BUOY AND SHIP OBSERVATIONS IN THE VICINITY OF THE TROUGH REVEAL A VERY DISTINCT NE TO SE WIND SHIFT FROM W TO E OF THE TROUGH. A PARTIAL ASCAT PASS FROM JUST PAST 14 UTC THIS MORNING SHOWED A TIGHT PRES GRADIENT E OF THE TROUGH S OF 25N INDUCING NE-E 20 KT WINDS. E-SE WINDS OF 15-20 KT ARE JUST SE OF THE TROUGH INCLUDING THE YUCATAN CHANNEL. ELSEWHERE...WINDS ARE GENERALLY NE-E 10-15 KT W OF THE TROUGH ...AND E-SE 10-15 KT E OF THE TROUGH. THE EXCEPTION IS IN THE ERN BAY OF CAMPECHE WHERE THERE ARE BRIEF INSTANCES OF 15-20 KT WINDS. 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 5-8 FT SEAS ARE NOTED. THE HIGHEST OF THIS RANGE IS CONFINED THE RIDGE OVER THE NRN AND CENTRAL PORTIONS WILL SLIDE S AND WEAKEN THROUGH MON ALLOWING FOR A WEAK FRONTAL BOUNDARY OVER THE MISSISSIPPI VALLEY TO SLOWLY MOVE S INTO THE FAR NRN WATERS MON TO ACROSS THE FAR NE GULF MON NIGHT TO E OF THE GULF BY EARLY TUE. WITH THE HIGH SLIDING SWD...THE TROUGH WILL BE FORCED WESTWARD WHILE WEAKENING THROUGH MON AND DISSIPATE MON NIGHT. THE PRES GRADIENT E OF THE TROUGH SLACKEN ALLOWING FOR THE NE-E 20 KT WINDS TO 10-15 KT MON. SEAS IN THE FAR SE PART LOWER TO 2-4 FT BY MON NIGHT. LATEST MODELS...SIMILAR TO EARLIER RUNS...IN SUGGESTING THAT ANOTHER COLD FRONT SWEEPS SEWD ACROSS THE NRN PORTIONS OF THE CENTRAL AND ERN GULF ON WED...FOLLOWED BY STRONGER HIGH PRES THAT BUILDS SEWD ACROSS THE 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 PLAINS SHOULD ALLOW FOR WINDS ACROSS THE WRN GULF TO VEER AROUND THE SE ON WED INTO FRI WHILE INCREASING IN SPEEDS. SEAS ARE FORECAST TO REMAIN NEAR CURRENT OBSERVED VALUES OVER MUCH OF THE MIDDLE AND WRN GULF THROUGH PERIOD WITH ONLY MODEST INCREASES IN THE FAR WRN PART THU AND FRI. IN THE ERN HALF OF THE GULF...SEAS WILL LOWER TO 1-2 FT BY TUE AND CONTINUE LIKEWISE THROUGH FRI. CARIBBEAN SEA AND TROPICAL ATLC S OF 19N W OF 55W... BUOY OBSERVATIONS FROM THIS MORNING AND EARLY AFTERNOON REVEAL VERY LIGHT TRADES ACROSS THESE WATERS AN ASCAT PASS FROM NEAR 15 UTC THIS MORNING VERIFIED THE LIGHT WIND CONDITIONS. NE-E WINDS OF 15 KT ARE ARE OVER THE FAR SE PART OF THE TROPICAL N ATLC. A TIGHTENING OF THE PRES GRADIENT THERE FROM WRN ATLC AND GULF OF MEXICO HIGH PRES WILL INCREASE WINDS TO 20 KT IN THE FAR NRN PORTION OF THE NW CARIBBEAN TONIGHT INCLUDING THE WINDWARD PASSAGE...THEN DIMINISH BY EARLY TUE. . 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 DOWN TO 3-5 FT...SIMILAR TO THE WAVEWATCH VALUES. BUOY 41040 E OF THE AREA AT 14N52W HAS SEAS OF 5-7 FT IN A NE SWELL. WINDS AND SEAS ARE FORECAST TO REMAIN ON THE LIGHT/LOW SIDE 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 BE AROUND 4-6 FT OVER MUCH OF THE AREA THROUGH MON...THEN BUILD TO 7 FT OVER THE CENTRAL PORTION LATER TUE THROUGH FRI AS A N SWELL TRAIN COMBINES WITH A NE SWELL TRAIN...HOWEVER MOST OF THE SWELL ENERGY SHOULD HAVE BEEN EXHAUSTED N AND NE OF THE FORECAST WATERS BEFORE THEY ARRIVE INTO THE ZONES. SOUTHWEST N ATLC FROM 19N TO 31N W OF 55W... THE PRELIMINARY 18 UTC SURFACE ANALYSIS SHOWS THE RECENT COLD FRONT NOW SLOWING DOWN AND BECOMING STATIONARY FROM 23N65W TO THE WINDWARD PASSAGE WHILE AT THE SAME TIME HIGH PRES IS BUILDING SEWD IN ITS WAKE. SCATTERED SHOWERS AND ISOLATED TSTMS ARE ALONG THE FRONT. RECENTLY ARRIVED ASCAT DATA SHOWS VEERING WINDS OF N-NE 20 KT BEHIND THE FRONT S OF ABOUT 25N. LIGHTER NLY WINDS ARE ELSEWHERE ACROSS THE BASIN. SEAS ARE SLOWLY SUBSIDING BEHIND THE FRONT WITH MAXIMUM SEAS OF 10 FT NOW NOTED WITHIN 120 NM NE OF THE BAHAMAS. SEAS OF 8 FT ARE POSSIBLE SW OF THE BAHAMAS AND NEAR THE STRAITS OF FLORIDA. SEAS ELSEWHERE ARE IN THE RANGE OF 5-7 FT IN N-NE SWELLS E OF 79W...AND LOWER IN THE RANGE OF 3-4 FT W OF 79W N OF THE NW BAHAMAS. THE FRONT WILL TRANSITION TO STATIONARY STATUS THROUGH MID WEEK BEFORE DISSIPATING. A RESIDUAL 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 AND MON BEFORE WEAKENING AND LIFTING N. 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. THE FRONT IS FORECAST TO THEN REACH FROM NEAR 31N75W TO VERO BEACH FLORIDA BY WED MORNING...THEN BEGIN TO SLOW DOWN AS IT REACHES FROM NEAR 31N67W TO 26N72W AND AS A WEAKENING STATIONARY FRONT TO THE CENTRAL BAHAMAS BY LATE THU...AND FROM NEAR 22N65W TO ERN HISPANIOLA BY EARLY FRI. THE TROUGH LEFT OVER FROM THE PREVIOUS FRONT MERGES WITH THIS FRONT LATE WED NIGHT INTO THU. NW WINDS OF 20 KT WILL FOLLOW BEHIND THIS FRONT WED INTO THU AS HIGH PRES BUILDS IN ITS WAKE. THESE WINDS SHOULD BE CONFINED TO THE WATERS N OF THE BAHAMAS. THEY THEN DIMINISH TO 15 KT LATER ON THU. SEAS BEHIND THE FRONT SHOULD PEAK TO AROUND 7 FT PER THE NWW3 WAVEWATCH GUIDANCE ON WED BEFORE SUBSIDING TO 6 FT THU AND TO 5 FT FRI. 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