000 AGXX40 KNHC 211737 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 140 PM EDT SAT APR 21 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... A SURFACE LOW IS OVER THE N-CENTRAL GULF TRAILING A COLD FRONT SW TO THE W BAY OF CAMPECHE WITH CONVECTION ORGANIZED OVER THE N-CENTRAL PORTION ALONG A PRE-FRONTAL LINE AS FORECAST. CONVECTION IS ALSO OCCASIONALLY FLARING ALONG THE FRONT OVER THE NW BAY OF CAMPECHE. A WARM FRONT IS OVER THE SE WATERS WITH CONVECTION EXPECTED TO CONTINUE TO FLARE AHEAD OF THE BOUNDARY AS IT PROGRESSES NE ACROSS THE FL PENINSULA TONIGHT. SLY FLOW AHEAD OF BOTH FRONTS EXPECTED TO MAX AT 25 KT WHILE NLY FLOW W OF COLD FRONT SHOULD PEAK AT 30 KT TODAY...DIMINISHING TO 25 KT TONIGHT...AND FURTHER DIMINISHING TO 20 KT ON SUN NIGHT. WINDS WILL CONTINUE TO DIMINISH TO BELOW 20 KT ALL AREAS BY SUNRISE TUE WITH SE FLOW ALREADY BEGINNING OVER THE EXTREME NW WATERS. THE RETURN FLOW WILL SPREAD E TO ALL WATERS W OF 87W WED AND ACROSS ALL WATERS E OF 87W WED NIGHT AS AN E-W RIDGE SETS UP ALONG 29N. SW NORTH ATLC S OF 31N W OF 65W... A RIDGE EXTENDS FROM A SURFACE HIGH JUST SE OF BERMUDA TO THE FL STRAITS. SOUTHERLY WINDS ARE INCREASING ACROSS THE WESTERN WATERS IN ADVANCE OF THE STRONG COLD FRONT THAT WILL MOVE OFF THE SE CONUS AT SUNRISE SUN. USING A BLEND OF GUIDANCE...WILL RACE A LOW PRES CENTER ALONG THE SE CONUS COAST TONIGHT TRAILING A COLD FRONT TO A POSITION FROM 31N75W TO NW CUBA AT SUNRISE MON...THEN SLOW THE FRONT REACHING FROM 31N67W TO HISPANIOLA AT SUNRISE TUE...FROM 31N62W TO 20N70W SUNRISE WED...AND FROM 31N57W TO 22N65W WITH REMNANTS OF THE SOUTHERN SEGMENT DRIFTING W TO NEAR THE WINDWARD PASSAGE AT SUNRISE THU. EXPECT SLY FLOW TO MAX AT 30 KT...WITH OCCASIONAL GUSTS TO GALE FORCE...AHEAD OF THE FRONT OVER THE NW WATERS...AND MAX AT 25 KT AHEAD OF FRONT AS FAR S AS THE BAHAMA CHANNEL AN CAY SAL BANK. THE POST FRONTAL NLY FLOW WILL BRIEFLY MAX AT 30 KT OVER THE WATERS N OF 30N AND MAX AT 25 KT ELSEWHERE. NW WINDS WILL DIMINISH BELOW 20 KT OVER THE ATLC WATERS W OF 79W TUE AS A RIDGE BUILDS W TO E ALONG 27N EARLY WED. AN EMBEDDED HIGH CENTER WILL SHIFT RAPIDLY E ALONG THE RIDGE WED NIGHT REACHING NEAR BERMUDA THU REVERSING THE RIDGE TO NNE-SSW BY LATE THU. CARIBBEAN SEA... SE LOW LEVEL FLOW WILL GRADUALLY INCREASE OVER THE NW CARIBBEAN AHEAD OF A COLD FRONT MOVING INTO THE YUCATAN CHANNEL LATE THIS AFTERNOON. THE FRONT WILL REACH FROM CENTRAL CUBA TO THE GULF OF HONDURAS SUN...THEN WEAKEN AND SLOW AS IT REACHES FROM E CUBA TO NE HONDURAS EARLY MON...AND STALL FROM NEAR THE WINDWARD PASSAGE TO NICARAGUA TUE...WITH THE REMNANTS DRIFTING W AND DISSIPATING OVER THE N CENTRAL AND NW WATERS ON WED. EXPECT THE POST FRONTAL NW WINDS TO BRIEFLY MAX AT 25 KT OVER THE NW CARIBBEAN SUN NIGHT...THEN GRADUALLY DIMINISH AND CLOCK TO THE NE BY TUE NIGHT. THE NE WINDS WILL INCREASE TO 20-25 KT IN THE WINDWARD PASSAGE AND ACROSS THE NW CARIBBEAN WED NIGHT. OTHERWISE...ELY WINDS WILL REMAIN AT 15 KT OVER THE E AND CENTRAL CARIBBEAN WATERS WITH SEAS TO 6 FT IN THE SW PART...AND GENERALLY SUBSIDING ELSEWHERE. TROPICAL N ATLC S OF 19N W OF 55W... GENERALLY NE-E 15 KT TRADES WILL CLOCK TO THE SE OVER THE NORTHERN PORTION SUN THROUGH WED THEN VEER BACK TO NE ON THU. SEAS IN THE 4-6 FT RANGE THROUGH THE PERIOD. 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 NELSON