000 AGXX40 KNHC 111837 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 250 PM EDT WED APR 11 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... WEAK 1020 MB SURFACE HIGH PRES CENTERED OFF THE SW LOUISIANA COAST NEAR 28N91W DOMINATES THE ENTIRE GULF WATERS PRODUCING MAINLY LIGHT WINDS AND RELATIVELY FLAT SEAS PARTICULARLY ACROSS THE NORTHERN GULF. BUOYS ARE REPORTING 1 TO 2 FT OVER THE NE GULF AND GENERALLY 2 TO 4 FT ELSEWHERE. WINDS WERE IN THE 10-15 KT RANGE NEAR THE COAST OF YUCATAN DURING THE MORNING HOURS DUE TO LOCAL EFFECTS. THE PATTERN WILL START TO CHANGE LATER TODAY AS A COLD FRONT CONTINUES TO MOVE SE ACROSS THE NE GULF. THE FRONT WILL REACH FROM THE TAMPA BAY AREA TO NEAR THE MISSISSIPPI RIVER DELTA TONIGHT...AND WILL START TO BECOME DIFFUSE AS IT SAGS FURTHER SOUTH THU REACHING FROM SW FLORIDA TO SW LOUISIANA BY LATE THU. HIGH PRES WILL BUILD OVER THE EASTERN UNITED STATES BEHIND THE FRONT WED THROUGH FRI. PRES GRADIENT BETWEEN THE HIGH AND A LOW PRES MOVING INTO THE CENTRAL PLAINS STATES WILL BRING AN INCREASE IN WINDS AND SEAS ACROSS THE WESTERN GULF. EXPECT 20 KT E TO SE WINDS BY FRI...AND 20 TO 25 KT SE WINDS BY SAT. WINDS AND SEAS WILL ALSO INCREASE ACROSS THE EASTERN GULF AND THE STRAITS OF FLORIDA LATE FRI INTO SAT. MARINE GUIDANCE SUGGESTS INCREASING WINDS TO 20-25 KT AND BUILDING SEAS TO 8 FT MAINLY ACROSS THE STRAITS OF FLORIDA. CARIBBEAN SEA... BUOY/SHIP OBSERVATIONS ALONG WITH SCATTEROMETER DATA SHOW FAIRLY LIGHT WINDS AND SEAS ACROSS ALMOST THE ENTIRE BASIN...WITH THE EXCEPTION OF THE FAR EASTERN PORTION OF THE CARIBBEAN NEAR THE LESSER ANTILLES AND ALSO NEAR THE COAST OF COLOMBIA WHERE 15 TO 20 KT TRADE WIND FLOW IS NOTED. AN EARLIER ASCAT PASS SHOWED NE TRADES TO 20 KT SLIPPING THROUGH THE WINDWARD PASSAGE AND JUST ON THE LEE SIDE OF EASTERN CUBA. THESE WINDS WILL DIMINISH TODAY AS THE HIGH PRES TO THE NORTH WEAKENS AND A COLD FRONT MOVES ACROSS THE SW N ATLC. WINDS WILL START TO INCREASE AGAIN BY LATE FRI INTO SAT AS HIGH PRES BUILDS AGAIN N OF THE AREA. EXPECT NE TRADE WINDS OF 20 KT N OF CUBA...THROUGH THE WINDWARD PASSAGE AND IN LEE OF CUBA. AS HIGH PRES MOVES FROM THE CAROLINAS INTO THE WESTERN ATLC OCEAN...EXPECT INCREASING WINDS ACROSS THE MONA PASSAGE AND MOST THE NORTHERN CARIBBEAN WATERS. ENSEMBLE WAVE GUIDANCE SHOWS SEAS BUILDING TO 6 TO 8 FT BY SUN PARTICULARLY S OF DOMINICAN REPUBLIC AND WEST OF THE CAYMAN ISLANDS. TROPICAL NORTH ATLANTIC S OF 19N W OF 55W... A RIDGE FROM THE CENTRAL ATLC EXTENDS SW INTO THE NORTHERN PORTION OF THE AREA. SOUTH OF THE RIDGE...MAINLY 15 TO 20 KT WINDS ARE NOTED E OF THE LEEWARD AND WINDWARD ISLANDS AS SHOWN BY SURFACE DATA AND THE MOST RECENT ASCAT PASS. THE FRESH TRADE WIND FLOW WILL PERSIST THROUGH THU THEN DIMINISH AS THE RIDGING TO THE NORTH WEAKENS AHEAD OF A COLD FRONT MOVING INTO THE AREA FROM THE WEST. NE SWELL WITH PERIODS AROUND 8 SECONDS WILL SPREAD INTO THE AREA W OF 55W THU ALLOWING SEAS TO BUILD TO AROUND 9 FT. SEA HEIGHTS WILL GRADUALLY SUBSIDE BY LATE FRI. SW NORTH ATLANTIC S OF 31N W OF 55W... WEAK RIDGE EXTENDING FROM 31N55W TO S FLORIDA DOMINATES THE AREA. A COLD FRONT HAS JUST MOVED INTO THE FAR NW WATERS. THE FRONT WILL SHIFT SE AND REACH FROM 31N73W TO CENTRAL FLORIDA BY THIS EVENING...AND FROM NEAR BERMUDA TO S FLORIDA EARLY THU. THEN...THE FRONT WILL EXTEND FROM 27N65W TO THE WINDWARD PASSAGE THU EVENING AND MOVE E OF 65W BY FRI. EXPECT INCREASING WINDS BETWEEN THE BAHAMAS AND CUBA...THEN MAINLY S OF 27N LATE FRI THROUGH SUN AS HIGH PRES MOVES FROM THE CAROLINAS INTO THE WESTERN ATLC. SEAS WILL BUILD TO AROUND 8 FT ACROSS THE SE WATERS BY SAT...REACHING 9 FT IN THE ATLC WATERS JUST EAST OF THE SOUTHERN BAHAMAS LATE SAT INTO SUN. 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 GR/EC