000 AGXX40 KNHC 050755 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 355 AM EDT SUN AUG 5 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 THE TROUGH LINGERING ACROSS THE FLORIDA PENINSULA AND INTO THE STRAITS...LEAVING A VERY WEAK 1017 MB HIGH CENTERED OFFSHORE OF THE PANHANDLE. LIGHT TO MODERATE WINDS CONTINUE TO PREVAIL ACROSS THE ENTIRE BASIN THIS MORNING AND SIMILAR CONDITIONS ARE EXPECTED TO PERSIST THROUGH LATE MON. SEAS WILL REMAIN 2 FT OR LESS E OF 90W...AND 2-3 FT W OF 90W EXCEPT OCCASIONALLY TO 4 FT IN THE SW GULF. MOISTURE AND INSTABILITY GENERATED BY UPPER LOW BISECTING GULF WILL MAINTAIN ACTIVE CNVTN TODAY ACROSS THE NW GULF. THE SURFACE TROUGH IS FORECAST TO MOVE W INTO THE E GULF TODAY...SLOWLY DRIFTING W AND REACHING 89W BY TUE EVENING. ERNESTO IS EXPECTED TO REACH HURRICANE STRENGTH 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... RECENT RECON INVESTIGATING TROPICAL STORM ERNESTO HAS FOUND DECREASED WINDS AND A PRES OF ONLY 1008 MB...AND LLVL CENTER RACING OFF TO THE NW AHEAD OF APPARENT WELL DEFINED MID LEVEL CIRCULATION. CENTRAL CARIB BUOY STILL HOLDING AT 6 FT ATTM AND IS WITHIN ABOUT 90 NM OF CENTER OF ERNESTO. WINDS AND SEAS ARE THUS DOWN SLIGHTLY WITH ERNESTO...BUT A BROAD WIND FIELD ACROSS THE NRN SEMICIRCLE CONTINUES TO PRODUCE A LARGE WAVE FIELD GENERALLY N OF 14N MOVING WITH THE SYSTEM...AND EXTENDS WILL E TO 65W/66W...WHERE BUOY 42059 IS STILL AT 9 FT. ERNESTO MAY HAVE INGESTED SOME OF THE DRY AIR SUGGESTED IN PW ANIMATIONS AND SAL PRODUCTS BUT IS EXPECTED TO CONTINUE ON ITS WNW TRAJECTORY AND REACH MORE FAVORABLE CONDITIONS IN THE W CARIB FOR INTENSIFICATION INTO A HURRICANE WITHIN 36-48 HOURS. CURRENT MAX SEAS ARE ESTIMATED NEAR 20 FT IN THE NE QUADRANT. 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 HAVE SPREAD FROM THE COASTAL WATERS OF HISPANIOLA W AND NW ACROSS THE WINDWARD PASSAGE AND JAMAICA OVERNIGHT AND WILL SHIFT NW TO THE CAYMANS LATER TODAY. 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 ACROSS THE FLORIDA PENINSULA CONTINUES TO DRIFT W...WITH MID LEVEL CYCLONE ACROSS N FLORIDA AIDING IN GENERATING SCATTERED TSTMS N OF 27N W OF 77W. RECENT BUOY AND SHIP OBSERVATIONS IN THE AREA FROM 27N TO 30N E OF THE TROUGH TO 77W SUGGESTS SE WINDS HAVE DIMINISHED TO 15-20 KT FROM THE AFTERNOON WINDS OF 20-25 KT SAT. 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 AND INTO THE E GULF TODAY AND E CENTRAL GULF BY LATE TUE. FRESH TO STRONG E WINDS ARE EXPECTED S OF 23N FROM THE NE CARIB THROUGH THE BAHAMAS THIS MORNING AND THEN SHIFT W IN TANDEM WITH ERNESTO AS IT MAKES ITS WAY WNW 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 HISPANIOLA THROUGH THE TURKS AND CAICOS TO THE CENTRAL BAHAMAS BY THIS AFTERNOON. ELSEWHERE AN ATLC RIDGE EXTENDS FROM 1027 MB HIGH PRES CENTERED N OF BERMUDA TO NEAR THE SC COAST. THIS HIGH AND ATTENDANT RIDGE WILL REMAIN NEARLY STATIONARY THROUGH MON AND HELP TO MAINTAIN THE TIGHTER PRES GRADIENT N AND NE OF ERNESTO. MEANWHILE TROPICAL STORM FLORENCE WELL E OF THE OFFSHORE AREA IS FORECAST TO CLIP ZONE AMZ127 LATE WED THROUGH THU. THE CURRENT NHC 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 AMZ019-021-023. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER STRIPLING