000 AGXX40 KNHC 080545 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 145 AM EDT SUN JUL 08 2012 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND SOUTHWEST NORTH ATLC S OF 31N W OF 55W. ................................................................. ATTENTION - SATELLITE TRANSMISSION OF NATIONAL WEATHER SERVICE HIGH SEAS FORECASTS HAS BEEN TEMPORARILY DISRUPTED. PLEASE VISIT THE FOLLOWING WEBSITE FOR MARINE FORECASTS: WWW.HURRICANES.GOV/MARINE ................................................................. GULF OF MEXICO... AN E TO W RIDGE WILL EXTEND ACROSS THE NORTHERN GULF THROUGH THE PERIOD. A SURFACE HIGH PRESSURE WILL DEVELOP OCCASIONALLY ALONG THE RIDGE AXIS OVER THE NE WATERS AS A WEAK N-S TROUGH FORMS OVER THE FL PENINSULA EFFECTIVELY SEPARATING THE GULF OF MEXICO SEGMENT OF THE RIDGE FROM THE PARENT ATLC RIDGE. THE NORTHERN EXTENSION OF A TROPICAL WAVE IS PASSING THROUGH THE S-CENTRAL GULF WATERS ACCOMPANIED BY SMALL CLUSTERS OF TSTMS. EXPECT THE WAVE TO INTO THE EASTERN BAY OF CAMPECHE LATE TODAY AND LEAVE A N-S TROUGH IN THE CENTRAL PORTION OF THE BAY THROUGH MON NIGHT. EXPECT SLY RETURN FLOW TO INCREASE TO 15-20 KT OVER THE W-CENTRAL WATERS MON NIGHT AND CONTINUE THROUGH WED NIGHT... WITH THE GRADIENT RELAXING SOME ON THU. AN UPPER CYCLONE IS QUASI STATIONARY AT 24N85W...AND AN UPPER ANTICYCLONE IS CENTERED OVER GUATEMALA WITH AN UPPER RIDGE EXTENDING NE TO A CREST OVER FL BAY. CONVECTIVE DEBRIS MOISTURE HAS SPREAD N ACROSS THE EXTREME SE GULF WATERS AND THE ASSOCIATED UPPER DIFFLUENCE IS SUPPORTING THE TSTMS MENTIONED JUST E OF THE TROPICAL WAVE AXIS. EXPECT THE PATTERN TO SHIFT A LITTLE W AND ENHANCE CONVECTION OVER THE BAY OF CAMPECHE MON THROUGH AT LEAST WED. DO NOT SEE TOO MUCH DIFFERENCE IN THE GUIDANCE ARRAY FOR LOW LEVEL WINDS...THUS BLENDED IN A SMALL PERCENT OF LATEST GFS INTO PREVIOUS FORECAST. SW N ATLC S OF 31N W OF 55W... A RIDGE EXTENDS E TO W FROM 30N55W TO NE FL. GUIDANCE CONSENSUS SUGGESTS THE RIDGE WILL MEANDER ALONG ROUGHLY THIS POSITION THROUGH EARLY MON BEFORE LIFTING N OF THE AREA TUE OVER THE WATERS E OF BERMUDA. THE W SEGMENT OF THE RIDGE WILL FLUCTUATE ACROSS THE NW WATERS BETWEEN 29N AND 31N THROUGH THU. SW WINDS N OF THE RIDGE WILL CONTINUE AT 10-15 KT...WHILE ELY WINDS S OF 23N WILL BE MOSTLY IN THE 15-20 KT RANGE AND MOSTLY SUSTAINED AT 20 KT ACROSS ZONE AMZ123. UPPER LEVEL DEBRIS MOISTURE CONTINUES TO ADVECT N FROM THE CARIBBEAN ACROSS THE FL STRAITS AND THE NW BAHAMAS. EXPECT CONVECTION TO BE ENHANCED ACROSS THE SW PORTION THROUGH AT LEAST MID WEEK AS ANOTHER TROPICAL WAVE IS ENTERING THE E PORTION...TO THE S OF 25N ALONG 57W ATTM. EXPECT THE WAVE TO REACH ALONG 66W EARLY TUE...AND MOVE THROUGH THE CENTRAL BAHAMAS WED AND W OF THE AREA THU NIGHT. THE WAVE IS CURRENTLY INTERACTING WITH AN UPPER TROUGH RESULTING IN CONVECTION FLARING NEAR 23N54W. BLENDED LATEST GFS INTO PREVIOUS FORECAST. CARIBBEAN SEA AND TROPICAL N ATLC W OF 55W... A TROPICAL WAVE HAS MOVED W OVER THE YUCATAN PENINSULA BUT UPPER SUPPORT CONTINUES TO ENHANCE CONVECTION OVER NW CARIBBEAN. ELY TRADES ARE AT MOSTLY 25-30 KT ACROSS THE S CENTRAL CARIBBEAN WITH 20-25 KT OBSERVED ACROSS THE CARIBBEAN ELSEWHERE BETWEEN 68W AND 82W...AND ALSO ACROSS THE NW WATERS IN THE AREA OF ENHANCED CONVECTION THIS MORNING. THE GFS RUNS SEEM TO HAVE A LITTLE BETTER HANDLE ON THE LOW LEVEL WINDS PER LATEST SCATTEROMETER DATA...WITH THE GFS SUGGESTING THE GRADIENT WILL RELAX SOME TONIGHT THROUGH TUE...THEN TIGHTENS THE GRADIENT AGAIN TUE NIGHT AND WED LIKELY DUE TO THE TROPICAL WAVE PASSING THROUGH THE NORTHERN WATERS. THUS...BLENDED LATEST GFS WITH PREVIOUS FORECAST PACKAGE. NOTE...GRIDDED MARINE OUTPUT IS AVAILABLE AT WWW.NHC.NOAA.GOV/TAFB/GRIDDED_MARINE GULF OF MEXICO... .NONE. CARIBBEAN SEA... .NONE. SW N ATLANTIC... .NONE. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ FORECASTER NELSON