000 AGXX40 KNHC 191711 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 111 PM EDT Wed Apr 19 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 few showers and thunderstorms are noted over the central and southwest Gulf this morning ahead of a sharp upper trough moving across the western Gulf. Gentle to moderate east to southeast flow continues across the Gulf, south of a weak surface ridge extending across the northern Gulf. The ridge will remain in place across the Gulf region through Friday. A thermally induced trough will develop over the Yucatan Peninsula late each afternoon. This trough will shift into the southwest Gulf each evening accompanied by moderate to fresh northeast winds, then it will dissipate each morning. Expect fresh southerly return flow across the northwest Gulf late Friday ahead of a weak cold front forecast to enter the northwest Gulf by Saturday afternoon. Fresh to strong northerly winds are expected behind the front, with seas building to 8 ft by Sunday morning. There is some disagreement among global models regarding the possibility of gale force winds off Veracruz Sunday. The latest GFS is outlier and strongest showing this. The official forecast is more of a consensus blend and while stronger than other operational and ensemble output, shows near gale force Sunday afternoon off Veracruz. Winds and seas diminish through late Sunday, as the front shifts east, sweeping southeast of the basin by early Monday. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Latest buoy observations and scatterometer data indicated moderate trade winds across most of the basin, except for locally fresh to strong winds south of Hispaniola and into the Windward Passage. Pulses of fresh to strong winds will persist in these areas and off Colombia through Sunday. Northerly swell continues to move through Atlantic passages into the eastern Caribbean, with buoys and altimeter passes indicating seas of 6 to 8 ft. Northerly swell is also apparent over the tropical Atlantic waters east of the Windward and Leeward Islands with seas reaching 8 to 11 ft. These seas will subside from north to south to 8-9 ft today, and are expected to subside below 8 ft by tonight. A cold front will move into the far northwest Caribbean Monday followed by fresh northwest winds. Otherwise little change is expected. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A mid level short wave trough and associated surface low pressure off the Carolinas have weakened the resident high pressure over the western Atlantic, resulting in gentle to moderate easterly winds across most of the region north of 24N. The exceptions farther south include the area between Haiti and the southern Bahamas, including the approaches to the Windward Passage where fresh to strong winds were noted earlier this morning. In addition, an earlier scatterometer pass indicated fresh easterly winds over the Cay Sal area of the Bahamas and the entrances to the Straits of Florida. Buoy and altimeter data indicate seas of 8 to 9 ft east of the southern Bahamas and Turks and Caicos Islands south of 24N. This is lingering northerly swell, expected to decay below 8 ft through late today. The ridge will become reestablished over along 27N/28N Friday. Southerly winds will increase off northeast Florida starting Saturday night, ahead of a cold front expected to move off the northeast Florida coast late Sunday. Looking ahead, the general consensus among global models shows a weak low pressure area forming along the boundary north of the northern Bahamas Monday, although there remains some uncertainty regarding exact position and intensity at this time. This may enhance southerly flow over the waters northeast of the Bahamas between the developing low pressure and the ridging shifting eastward. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 Christensen. National Hurricane Center.