000 AGXX40 KNHC 170738 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 338 AM EDT SUN MAY 17 2015 MARINE WEATHER DISCUSSION FOR THE GULF OF MEXICO...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W...AND THE SW N ATLANTIC INCLUDING THE BAHAMAS. ...GULF OF MEXICO... MODEL PREFERENCE: FOR WINDS LATEST GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. FOR WAVE PARAMETERS LATEST MWW3 BLENDED WITH PREVIOUS OFFICIAL FORECAST. HIGH CONFIDENCE. SEVERAL REPORTS OF LIGHT FOG ARE NOTED ACROSS THE NW GULF. A SURFACE RIDGE CONTINUES TO DOMINATE THE GULF REGION AND EXTENDS FROM THE FLORIDA BIG BEND TO THE NE COAST OF MEXICO. THE MOST RECENT SCATTEROMETER DATA SHOW SE-S WINDS OF 15-20 KT ACROSS THE WESTERN GULF DUE TO THE PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES OVER EASTERN TEXAS AND NE MEXICO. E-SE WINDS OF 10-15 KT ARE OBSERVED ALONG THE RIDGE AXIS OVER THE NE WATERS. IN ADDITION... THE THERMAL TROUGH OVER THE NW YUCATAN PENINSULA WILL DRIFT WESTWARD AND CONTINUE TO ENHANCE THE WINDS ACROSS THE SW GULF EACH EVENING THROUGH MON. THESE E-SE PULSES OF MAINLY 20-25 KT WILL PROPAGATE WNW ACROSS THE SW GULF OF MEXICO E OF AN INVERTED TROUGH DURING THE MORNING DAYLIGHT HOURS...WITH THE TROUGH LOSING IDENTITY AND WINDS DIMINISHED TO 15-20 KT BY THE EARLY AFTERNOONS. EXPECT BUILDING SEAS OF 6-7 FT WITH THE STRONGEST WINDS. OTHERWISE...SEAS WILL BE GENERALLY UNDER 6 FT ACROSS THE WESTERN GULF AND UNDER 4 FT ACROSS THE EASTERN GULF. A SURFACE HIGH WILL DEVELOP ALONG THE RIDGE OVER THE NE GULF ON MON NIGHT AND THEN MEANDER OVER THE NE WATERS THROUGH THE END OF THE FORECAST PERIOD. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: FOR WINDS LATEST GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. FOR WAVE PARAMETERS LATEST MWW3 BLENDED WITH PREVIOUS OFFICIAL FORECAST. HIGH CONFIDENCE. A HIGH RESOLUTION ASCAT PASS PROVIDED OBSERVATIONS OF NE-E WINDS IN THE 20-30 KT RANGE ACROSS THE SOUTH-CENTRAL CARIBBEAN WHILE AN ALTIMETER PASS INDICATED SEAS OF UP TO 10 FT WITH THESE FRESH TO STRONG WINDS. FRESH TO LOCALLY STRONG EASTERLY WINDS ARE ALSO NOTED ACROSS THE GULF OF HONDURAS PER THE SAME SCATTEROMETER PASS. EXPECT TRADE WINDS OF 20-30 KT AND BUILDING SEAS OF 8-11 FT ACROSS THE SOUTH-CENTRAL CARIBBEAN THROUGH TONIGHT...WITH WIND DIMINISHING TO 20-25 KT THEREAFTER AS HIGH PRES LOCATED N OF AREA WEAKENS. THE PRES GRADIENT IS FORECAST TO WEAKEN CONSIDERABLY TUE THROUGH THU WITH ONLY MODERATE TO FRESH TRADES ACROSS THE SOUTH-CENTRAL CARIBBEAN. THEN...THE PRES GRADIENT MAY TIGHTEN SLIGHTLY THU EVENING THROUGH FRI WITH 20-25 KT CONDITIONS EXPECTED ACROSS THE CENTRAL CARIBBEAN. MODERATE TO FRESH TRADE WINDS WILL PREVAIL ACROSS THE REMAINDER OF THE AREA S OF 17N AND MODERATE TRADES N OF 17N. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: FOR WINDS LATEST GFS BLENDED WITH PREVIOUS OFFICIAL FORECAST. FOR WAVE PARAMETERS LATEST MWW3 BLENDED WITH PREVIOUS OFFICIAL FORECAST. MEDIUM-HIGH CONFIDENCE. A WEAKENING FRONTAL BOUNDARY WILL PERSIST ACROSS THE SE WATERS THROUGH AT LEAST MON ACCOMPANIED BY SOME SHOWER ACTIVITY. HIGH PRES IN THE WAKE OF THIS FRONT WILL SHIFT S REACHING A POSITION NEAR 31N70W TONIGHT...AND NEAR 28N73W ON MON NIGHT WHILE BEGINS TO WEAKEN. THEN...THE HIGH PRES CENTER WILL SHIFT FARTHER S TO NEAR 27N74W BY EARLY TUE AS A COLD FRONT CLIPS THE FAR NE WATERS. WINDS AND SEAS WILL BRIEFLY INCREASE ACROSS THE NE WATERS WITH THE FRONTAL PASSAGE. AS A RESULT...EXPECT W-NW WINDS OF 15-20 KT WITH BUILDING SEAS OF 6-7 FT. ANOTHER COLD FRONT WILL REACH THE FAR NW WATERS LATE WED AND EXTEND ACROSS THE FAR N WATERS MAINLY W OF 70W BY THU. GENTLE TO MODERATE SW WINDS AND SEAS OF 3-4 FT ARE EXPECTED AHEAD OF THE FRONT. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *FOR DETAILED ZONE DESCRIPTIONS PLEASE VISIT: HTTP://WWW.NHC.NOAA.GOV/ABOUTTAFBPROD.SHTML#OWF NOTE: GRIDDED MARINE FORECASTS ARE AVAILABLE IN THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AT: HTTP://WWW.NHC.NOAA.GOV/MARINE/GRIDS.PHP FOR ADDITIONAL INFORMATION PLEASE VISIT: HTTP://WWW.HURRICANE WARNINGS.GOV/MARINE $$ .FORECASTER GR. NATIONAL HURRICANE CENTER.