000 AGXX40 KNHC 161901 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 301 PM EDT Wed Aug 16 2017 Marine Weather Discussion for the Gulf of Mexico, Caribbean Sea, and Tropical North Atlantic from 07N to 19N between 55W and 64W and the Southwest North Atlantic including the Bahamas. ...GULF OF MEXICO... The main feature continues to be the western extension of the Atlantic sub-tropical ridge that reaches across the central Gulf, with a 1019 mb center at 28N84W at 16/1200 UTC. The associated anticyclonic flow consists of light to gentle winds in the basin. Moderate to fresh southerly winds being observed in the far western Gulf will diminish this afternoon, then briefly materialize tonight before diminishing again on Thursday. Seas to 6 ft associated with these winds will lower to around 4 ft on Thursday. The ridge will lift northward to the northern Gulf on Friday, and remain nearly stationary through the weekend. Moderate NE to E winds over the eastern Bay of Campeche will pulse to fresh to strong at night through the period. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... A tropical wave is analyzed near 84W at 18Z, moving westward at 20-25 kt. The wave will move across the remainder of the western Caribbean through Thursday. A broad tropical wave is in the eastern part of the area, with rainshowers around it. This wave will move quickly through the Tropical N Atlantic waters through Thursday afternoon, across the central Caribbean Thursday beginning late Thursday afternoon through Friday afternoon, and the western Caribbean Friday night through Saturday evening. The next tropical wave or low pressure system will move across the eastern Tropical N Atlantic waters Thursday afternoon, and the rest of the Tropical N Atlantic through Friday morning, then across the eastern Caribbean Friday afternoon through Saturday night and the central Caribbean Sunday and Sunday night. Fresh to strong winds, locally gusty at times, will accompany this system along with scattered to numerous showers and thunderstorms. Scattered showers and thunderstorms in the far SW Caribbean will continue to pulse from time to time through the forecast period. ...SW N ATLANTIC INCLUDING THE BAHAMAS... The sub-tropical Atlantic ridge will become established along along 27N through tonight. It will then shift N to near 28N Thursday through Friday, N to 29N on Saturday and to along 31N on Sunday. The northern part of a broad tropical wave is passing across the far SE portion of the area. Associated scattered showers and isolated thunderstorms cover most of that zone. The wave is moving through the eastern Caribbean now. The pressure gradient that exists between it and the Atlantic ridge will increase the winds and wave heights in the far southern waters tonight through at least early Friday afternoon, with easterly winds reaching the fresh to locally strong range and seas expected to build to around 6 or 7 ft. A 1010 mb low pressure center is near 14N along a tropical wave that is along 35W. This low center is in the medium category for possible development into a tropical cyclone in 48 hours. A second 1010 mb low pressure center is near 14N along a tropical wave that is along 47W. This low center also is in the medium category for possible development into a tropical cyclone. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.nhc.noaa.gov/marine $$ .Forecaster MT. National Hurricane Center.