000 AGXX40 KNHC 310722 MIMATS MARINE WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 322 AM EDT SUN AUG 31 2014 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: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL. NWPS USED FOR WAVE PARAMETERS. MEDIUM CONFIDENCE. SCATTERED SHOWERS ALONG WITH A FEW THUNDERSTORMS REMAIN ACTIVE OVER THE FAR SE GULF TONIGHT. AN EARLIER ASCAT PASS ALONG WITH CMAN OBSERVATIONS IN THE FLORIDA KEYS INDICATED EASTERLY WINDS TO AT LEAST 20 KT WERE IN PLACE IN THE STRAITS OF FLORIDA AND ADJACENT GULF WATERS E OF 87W. THIS IS IN AN AREA BETWEEN THE NORTHERN PORTION OF A TROPICAL WAVE OVER THE YUCATAN PENINSULA AND RIDGING EXTENDING EAST TO WEST ACROSS THE NORTHERN GULF COAST. BUOY OBSERVATIONS INDICATE SEAS AROUND 3 TO 5 FT ACROSS THE GULF...BUT MAY BE APPROACHING 7 FT IN THE FAR SE WATERS. THE MAIN FORECAST ISSUE FOR THE UPCOMING SEVERAL DAYS RELATES TO THE TROPICAL WAVE CURRENTLY MOVING ACROSS THE YUCATAN PENINSULA AND THAT WILL BE DRIFTING ACROSS THE FAR SW GULF WATERS THROUGH MID WEEK. GLOBAL MODELS CONTINUE TO INDICATE WEAK LOW PRES WILL FORM ALONG THE TROPICAL WAVE IN THE BAY OF CAMPECHE...BUT NOT DEEPEN APPRECIABLY AS IT REMAINS IN THE SW GULF WATERS THROUGH THU. THERE IS STILL SOME UNCERTAINTY HOWEVER CONCERNING THE STATUS OF THIS LOW PRES BY MID WEEK GIVEN LOCAL PROCESSES IN THE SW GULF THAT ARE OFTEN NOT HANDLED WELL BY MODELS. THE OFFICIAL FORECAST CONTINUES TO SHOW FRESH TO STRONG E TO SE WINDS SETTING UP BY TUE FROM THE NW COAST OF YUCATAN TO NE MEXICO...BETWEEN THE LOW PRES AND RIDGING N OF THE AREA...WITH SEAS BUILDING TO 9 FT. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL. NWPS USED FOR WAVE PARAMETERS. MEDIUM CONFIDENCE. A SCATTEROMETER SATELLITE PASS FROM AROUND 0230 UTC INDICATED TRADEWINDS IN EXCESS OF 25 KT PERSISTING OVER THE S CENTRAL CARIBBEAN. THIS IS LARGELY DUE TO A TIGHT PRESSURE GRADIENT BETWEEN HIGH PRES OVER THE NW ATLANTIC BUILDING IN THE WAKE OF A TROPICAL WAVE THAT MOVE THROUGH THE NW CARIBBEAN INTO YUCATAN PENINSULA YESTERDAY. BUOY OBSERVATIONS INDICATED SEAS OF 8 TO 10 FT IN THIS AREA AS WELL. THE GFS INDICATES THAT THE FOCUS OF THE STRONGER WINDS WILL SHIFT FARTHER WEST LATER TODAY...WITH 25 KT SE WINDS EXPECTED OVER THE NW CARIBBEAN INTO THE EASTERN COAST OF YUCATAN AS LOW PRES DEVELOPS ALONG THE TROPICAL WAVE AS IT MOVES INTO THE FAR SW GULF OF MEXICO. SEAS IN THE NW CARIBBEAN WILL BUILD TO 8 TO 10 FT BY THIS EVENING. THE FRESH TO STRONG SE FLOW WILL PERSIST THROUGH LATE MONDAY AND INCLUDE THE GULF OF HONDURAS MON NIGHT. GIVEN LOCAL EFFECTS IN THIS PART OF THE CARIBBEAN...THE STRONGER GFS SOLUTION SEEMS MORE PLAUSIBLE THAN THE WEAKER ECMWF AND UKMET. A SECOND AND WEAKER TROPICAL WAVE NEAR 57W IN THE TROPICAL N ATLC WATERS IS ENTERING THE EASTERN CARIBBEAN CURRENTLY AND WILL MOVE THROUGH THE CENTRAL CARIBBEAN MON AND TUE. A THIRD AND MORE DEVELOPED TROPICAL WAVE WILL PASS WEST OF 55W TONIGHT AND APPROACH THE EASTERN CARIBBEAN LATE MON INTO TUE...THEN MOVE THROUGH THE CENTRAL CARIBBEAN THROUGH MID WEEK. MODERATE TO FRESH WINDS AND SEAS GENERALLY UNDER 7-8 FT ARE EXPECTED IN ASSOCIATION WITH THESE TWO TROPICAL WAVES...EXCEPT FOR STRONGER WINDS PULSE DURING THE LATE NIGHT AND EARLY MORNING HOURS OFF THE COAST OF COLOMBIA. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: LATEST GFS BLENDED WITH PREVIOUS OFFICIAL. NWW3 USED FOR WAVE PARAMETERS. MEDIUM TO HIGH CONFIDENCE. A RIDGE WILL DOMINATE THE AREA THROUGH THE FORECAST PERIOD. IT WILL MAINTAIN GENERALLY LIGHT TO MODERATE E TO SE FLOW THROUGH MID WEEK EXCEPT FOR OCCASIONALLY MODERATE TO FRESH TRADE WINDS ACROSS THE SOUTH WATERS MAINLY IN THE SOUTHERN BAHAMAS...TURKS AND CAICOS ISLANDS AND OFF HISPANIOLA. SOME SHOWER ACTIVITY WITH ISOLATED TSTMS IS NOTED OVER THE WATERS FROM 22N TO 27N E OF 70W IN ASSOCIATION WITH A LARGE UPPER-LEVEL LOW CENTERED NEAR 24N69W. WINDS AND SEAS COULD BE HIGHER NEAR THE TSTMS. $$ .WARNINGS...ANY CHANGES IMPACTING COASTAL NWS OFFICES WILL BE COORDINATED THROUGH AWIPS 12 PLANET CHAT OR BY TELEPHONE: .GULF OF MEXICO... NONE. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... NONE. .SW N ATLANTIC INCLUDING THE BAHAMAS... NONE. $$ *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 CHRISTENSEN. NATIONAL HURRICANE CENTER.