000 AGXX40 KNHC 041812 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 212 PM EDT SAT AUG 4 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. GULF OF MEXICO... THE WESTERN EXTENSION OF THE W ATLC RIDGE HAS BECOME CUT OFF OR BLOCKED IN THE GULF BY A TROUGH REACHING FROM JUST W OF JACKSONVILLE FLORIDA SE TO 27N80W TO 23N80W. LIGHT TO MODERATE WINDS CONTINUE TO PREVAIL ACROSS THE ENTIRE BASIN AND THESE CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE WEEKEND. SEAS WILL BE 2 FT OR LESS E OF 90W...AND 2-3 FT W OF 90W EXCEPT OCCASIONALLY TO 4 FT IN THE SW GULF. THE TROUGH IS FORECAST TO MOVE INTO THE E GULF SUN MORNING...SLOWLY DRIFTING W THROUGH THE WEEK AHEAD OF ERNESTO. ERNESTO IS EXPECTED TO BE A HURRICANE AS IT REACHES THE YUCATAN PENINSULA LATE TUE INTO EARLY WED. WINDS AND SEAS WILL INCREASE LATE TUE THROUGH WED IN THE YUCATAN CHANNEL AHEAD OF ERNESTO...WITH TROPICAL STORM CONDITIONS SPREADING N INTO THE EXTREME S CENTRAL/SE GULF WED...AND ACROSS THE YUCATAN AND E BAY OF CAMPECHE DURING LATE WED INTO THU. CARIBBEAN SEA AND TROPICAL ATLC W OF 55W... TROPICAL STORM ERNESTO HAS NOT STRENGTHENED THIS MORNING IN THE E CARIBBEAN WHILE MOVING W-NW AT 16 KT...ALTHOUGH MORE RECENT SATELLITE PRESENTATIONS WOULD INDICATE THAT THERE IS SOME INTENSIFICATION OCCURRING EARLY THIS AFTERNOON. CURRENT MAX SEAS ARE TO 17 FT IN THE NE QUADRANT AND NDBC BUOY 42059 ABOUT 60 NM NE OF THE CENTER OF ERNESTO REPORTED SEAS TO 14 FT AND TROPICAL STORM FORCE GUSTS THIS MORNING. LITTLE CHANGE HAS OCCURRED WITH RESPECT TO RECENT FORECASTS IN TERMS OF THE TRACK. ERNESTO IS FORECAST TO STRENGTHEN TO A HURRICANE SUN EVENING...WITH GRADUAL STRENGTHENING CONTINUING PRIOR TO REACHING THE YUCATAN PENINSULA WED. THE HIGHEST WINDS AND SEAS WILL REMAIN ACROSS N/NE SEMICIRCLE OF THE CYCLONE...AND MARINE CONDITIONS WILL BE SIGNIFICANTLY LESS IN SOUTHERN PORTIONS OF THE CARIBBEAN. HAZARDOUS MARINE CONDITIONS AFFECTING THE E CARIBBEAN WILL SPREAD INTO THE COASTAL WATERS OF HISPANIOLA THIS EVENING...AND THEN TO ACROSS THE WINDWARD PASSAGE AND JAMAICA LATE TONIGHT. REFER TO WTNT25 KNHC FORECAST ADVISORY FOR MORE DETAILED INFORMATION. CONDITIONS WILL GRADUALLY IMPROVE BY THE END OF THE WEEK (THU AND FRI) IN THE WAKE OF ERNESTO. SW N ATLC S OF 31N W OF 55W... A SURFACE TROUGH REACHES FROM INLAND JUST W OF JACKSONVILLE FLORIDA TO 27N80W TO 23N80W. A SURFACE LOW IS ALONG THIS TROUGH NEAR 28N80W. RECENT BUOY AND SHIP OBSERVATIONS IN THE AREA FROM 27N TO 30N E OF THE TROUGH TO 77W INDICATED SE 20-25 KT WINDS AND SEAS TO 9 FT...WITH HEAVY SCATTERED SHOWERS AND TSTMS WITHIN 180 NM E-SE OF THE TROUGH AXIS. OTHERWISE LIGHT TO MODERATE E-SE WINDS WITH SEAS 3-5 FT ARE EXPECTED OVER WATERS N OF 23N THROUGH SUN. THE TROUGH IS FORECAST TO GRADUALLY SHIFT W THIS EVENING ...MOVING OVER FLORIDA TONIGHT INTO SUN. FRESH TO STRONG E WINDS ARE EXPECTED S OF THE BAHAMAS THIS WEEKEND AS ERNESTO MAKES ITS WAY FROM THE E CARIBBEAN THROUGH THE CENTRAL CARIBBEAN. SEA HEIGHTS ARE EXPECTED TO BUILD TO 7-9 FT IN E SWELL FOR THE WATERS S OF 23N. DRY AIR PERSISTING TO THE NW OF ERNESTO MAY CONTINUE TO BECOME ENTRAINED AND YIELD SQUALLS WELL REMOVED FROM THE SYSTEM...ALLOWING FOR STRONG WIND GUSTS TODAY ACROSS THE ATLC WATERS OF PUERTO RICO AND HISPANIOLA. ELSEWHERE AN ATLC RIDGE EXTENDS FROM 1026 MB HIGH PRES CENTERED NE OF BERMUDA TO JUST NE OF THE CENTRAL/SE BAHAMAS. THIS HIGH AND ATTENDANT RIDGE WILL REMAIN NEARLY STATIONARY THROUGH THE WEEKEND. ANOTHER SURFACE TROUGH IS FORECAST TO MOVE INTO THE OFFSHORE WATERS W OF 65W MON SLOWLY DRIFTING W TOWARD THE BAHAMAS TUE-WED. MEANWHILE TROPICAL STORM FLORENCE WELL E OF THE OFFSHORE AREA IS FORECAST TO CLIP ZONE AMZ127 LATE WED THROUGH THU. THE OFFICIAL FORECAST HAS FLORENCE AS A POST-TROPICAL/REMNANT LOW AT THAT TIME. NOTE...GRIDDED MARINE FORECAST IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA... .TROPICAL STORM WARNING AMZ021-023-031-033. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER LEWITSKY