000 AGXX40 KNHC 040754 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 355 AM 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... WESTERN EXTENSION OF W ATLC RIDGE HAS BECOME CUT OFF OR BLOCKED FROM GULF BY TROPICAL WAVE/TROUGH ALONG E COAST OF FLORIDA THIS MORNING. LIGHT TO MODERATE WINDS WILL PREVAIL ACROSS THE ENTIRE BASIN THROUGH THE WEEKEND...WITH SEAS 2 FT OR LESS E OF 90W... AND 2-3 FT W OF 90W EXCEPT POSSIBLY TO 4 FT IN EXTREME S BAY OF CAMPECHE SAT. ERNESTO IS EXPECTED TO BE A HURRICANE AS IT REACHES THE YUCATAN PENINSULA WED. WINDS AND SEAS WILL INCREASE LATE TUE IN THE YUCATAN CHANNEL AHEAD OF ERNESTO...WITH TROPICAL STORM CONDITIONS SPREADING N INTO THE EXTREME SERN GULF EARLY WED AND ACROSS YUCATAN AND INTO SW GULF DURING THE DAY WED. SW N ATLC S OF 31N W OF 55W... ATLC RIDGE N OF 30N EXTENDING SW TO N FLORIDA WILL REMAIN NEARLY STATIONARY THROUGH THE WEEKEND. A SURFACE TROUGH BETWEEN THE E COAST OF FLORIDA AND THE BAHAMAS IS EXPECTED TO MOVE SLOWLY W-NW ACROSS SE FLORIDA TODAY THROUGH TONIGHT...AND GENERATE ACTIVE DEEP CONVECTION ACROSS THE PENINSULA TODAY...AND ALONG AND BEHIND TROUGH AXIS ACROSS THE BAHAMAS AND ADJACENT WATERS. LIGHT TO MODERATE E-SE WINDS WITH SEAS 3-4 FT ARE EXPECTED OVER WATERS N OF 23N THROUGH SUN. FRESH TO STRONG E WINDS ARE EXPECTED S OF THE BAHAMAS THIS WEEKEND AS ERNESTO MAKES ITS PATH THROUGH THE CARIBBEAN. SEA HEIGHTS EXPECTED TO BUILD TO 7-9 FT IN E SWELL FOR WATERS S OF 23N. DRY AIR PERSISTING TO THE NW OF ERNESTO MAY CONTINUE TO BECOME ENTRAINED AND YIELD SQUALLS WELL REMOVED FROM THE STORM...ALLOWING FOR STRONG WIND GUSTS TODAY ACROSS ATLC WATERS OF PUERTO RICO AND DOMINICAN REPUBLIC. CARIBBEAN SEA AND TROPICAL ATLC W OF 55W... TROPICAL STORM ERNESTO HAS SLOWED ITS FORWARD MOTION TO NEAR 16 KT THIS MORNING AND APPEARS TO BE ALLOWING CNVTN TO BETTER WRAP INTO LLVL CIRCULATION CENTER. DESPITE FORECAST OF MJO RELATED UPPER CONDITIONS TO BECOME UNFAVORABLE AHEAD OF ERNESTO NEXT 2 DAYS...CONVECTION NEAR ERNESTO IS MUCH IMPROVED FROM 24 HOURS AGO. LITTLE CHANGE TO RECENT FORECASTS IN TERMS OF TRAJECTORY WITH JUST A SLIGHT SHIFT TO THE RIGHT BEYOND DAY 3. FAVORABLE CONDITIONS ARE EXPECTED ACROSS THE W AND NW CARIBBEAN BY LATE MON AND TUE AND ARE EXPECTED TO ALLOW ERNESTO TO GRADUALLY INTENSIFY AND BECOME A HURRICANE IN WESTERN CARIBBEAN. HIGHEST WINDS AND SEAS WILL REMAIN ACROSS N SEMICIRCLE OF THE CYCLONE AND MARINE CONDITIONS WILL BE SIGNIFICANTLY LESS IN SOUTHERN PORTIONS OF THE CARIBBEAN. HAZARDOUS MARINE CONDITIONS AFFECTING THE NE CARIB ATTM WILL SPREAD INTO THE COASTAL WATERS OF THE HISPANIOLA TODAY...ACROSS THE WINDWARD PASSAGE BY THIS EVENING AND INTO JAMAICA TONIGHT. REFER TO WTNT25 KNHC FORECAST ADVISORY FOR MORE DETAILED INFORMATION. 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 STRIPLING