000 AGXX40 KNHC 241918 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 318 PM EDT Mon Apr 24 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 ----------------------------------------------------------------- PREVIOUS DISCUSSION.... ...GULF OF MEXICO... A cold front extends from the Florida Big Bend to near Tuxpan Mexico. Moderate to fresh northerly winds and seas up to 6 ft are noted in the wake of the front, forecast to reach from south Florida to the Yucatan Peninsula late this morning, pushing SE of the Gulf late today. Weak high pressure will build behind the front with decreasing winds and seas by late today into Tuesday. By mid week, fresh to strong southerly return flow is forecast to develop over the western half of the Gulf between a ridge extending from the Atlantic into the Gulf waters and a low pressure system over northern Texas and NE Mexico. Seas are expected to build to 7-8 ft across the NW Gulf by Wednesday morning in association with these winds. The next cold front will enter the Gulf region by Wednesday night and extend from SE Louisiana to near Tampico Mexico by Thusrday morning, and from the western Florida Panhandle to the Bay of Campeche by Thursday afternoon. Then, it is forecast to lift N by Thursday night with a southerly return flow dominating most the Gulf at that time. Moderate to fresh northerly winds are expected in the wake of this second front with building seas to 5-6 ft. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... The most recent scatterometer data indicate moderate to locally fresh NW winds over the NW Caribbean and the Yucatan Channel, behind a trough that extends from a low pressure in the northern Bahamas to near 20N83W. Mainly light and variable winds are noted over the central Caribbean, while moderate to fresh easterly winds dominate the eastern Caribbean on the SW periphery of a high pressure center located near 28N63W. A cold front will enter the northwest Caribbean late today, then will reach from central Cuba to northern Honduras tonight into Tuesday before dissipating. Moderate to fresh NW winds are forecast behind the front today. Then, expect light to gentle winds across the western half of the Caribbean Tuesday and Tuesday night. Mainly moderate to fresh trade winds will prevail across the remainder of the basin and Tropical North Atlantic waters throughout the forecast period. Northeast swell continues to affect the Atlantic passages in the northeast Caribbean, including the Anegada and Mona Passages, and also the Tropical N Atlantic waters with seas of 6-7 ft. Seas will subside to 4-6 ft across those areas on Tuesday. Then, expect increasing winds and building seas across the south-central Caribbean Wednesday night through Fri night, with the strongest winds of 20-25 kt and seas of 6-9 ft near the coast of Colombia by Friday night. ...SW N ATLANTIC INCLUDING THE BAHAMAS... Since yesterday, a low pressure has moved from the SE Gulf across South Florida into the NW Bahamas producing numerous showers and some thunderstorms. The low pressure is very well defined using night channel visible imagery. The center of 1006 mb is just north of the Grand Bahama Island. A trough extends from the low center across central Cuba into the NW Caribbean. The most recent scatterometer data indicate fresh to strong winds within about 90 nm north semicircle of the low, with mainly moderate to fresh southerly winds just ahead of the trough axis. The pressure gradient between this deepening low and the high pressure to the east will result in strong to near gale force southeast winds developing northeast of the Bahamas through tonight, with seas building to 8 to 12 ft. Sustained winds to minimal gale force are anticipated across forecast zone AMZ113, east of the low today before the low moves north of the area. As the low merges with a frontal system later today, a cold front will cross the NW waters. The front will then reach from 31N75W to central Cuba on Tuesday morning, with strong southerly winds persisting east of the front. Winds and seas will gradually diminish by Wednesday across the forecast region as the low lifts well north of the area and the associated cold front dissipates over the SW N Atlantic waters. By that time, a ridge, with axis along 29N, will dominate the forecast region. This ridge will persist through Friday. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ113...ATLANTIC FROM 27N TO 31N BETWEEN 70W AND 77W... Gale Warning today. $$ *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 GR/SS. National Hurricane Center.