000 AGXX40 KNHC 180648 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 248 AM EDT Thu May 18 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... A surface ridge extends along the U.S. Gulf coast states, anchored by a surface high in the Atlantic near Bermuda. Moderate to fresh southerly flow dominates the basin, except locally strong through the Straits of Florida, and gentle in the NE Gulf where the gradient is weaker. Seas are 4 to 6 ft across most of the Gulf, except up to 8 ft through the Straits of Florida, and 2 to 4 ft in the NE Gulf. Winds will pulse locally to fresh to strong NW of the Yucatan peninsula each evening with the typical thermal trough developing each afternoon just inland. Winds will also pulse to fresh to strong through the Straits of Florida during the next couple of evenings, as a weakening surface trough moves across Florida into the eastern Gulf. Otherwise, ridging will hold just north of the area through the weekend with moderate to fresh E to SE flow prevailing. Southerly flow over the NW Gulf will diminish by late Sunday as a weak cold front moves off the Texas coast. The majority of the front will remain N of the area while the southern portion attempts to shift eastward across the northern Gulf through early next week. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... A sharp upper trough reaching from the northern Bahamas to Honduras is supporting an area of showers and thunderstorms across the N central Caribbean, with a large and persistent complex of numerous showers and scattered thunderstorms along and to the S of Haiti where devastating flooding continues to occur. An associated surface trough reaches from the central Bahamas to across central Cuba to near the Honduras/Nicaragua border. A tight gradient between the subtropical ridge north of the area and the trough is supporting fresh to strong trade winds across mainly the N central Caribbean. The ridge will build N of the eastern Caribbean and tropical N Atlantic W of 55W as the trough moves slowly west through Saturday. This will be in phase with the westward exit of a weak tropical wave farther S in the deep tropics. These shifts will allow the area of fresh to strong winds to expand into the southern Caribbean and slightly more W, with fresh to strong trade winds and seas to 9 ft between Colombia and Jamaica by Friday. Meanwhile, NE to E swell to 8 ft will propagate into the tropical north Atlantic waters E of the Windward Islands by Friday. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A surface trough extends from the central Bahamas to the SW across central Cuba and into the NW Caribbean, while ridging extends along 32N anchored by a high center near Bermuda. Fresh to locally strong winds are blowing from N of Hispaniola and offshore of northern Cuba through the Straits of Florida, with moderate to locally fresh E to SE flow elsewhere. The pressure gradient will relax a little by Saturday after the trough moves well W of the region. A weak cold front over the SE United States will approach the NE Florida coast by early next week, with little impact on winds or seas anticipated so far. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 Lewitsky. National Hurricane Center.