000 AGXX40 KNHC 171811 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 111 PM EST Tue Jan 17 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... MODEL PREFERENCE: Global model consensus. Medium to high confidence. A ridge axis extends across the northern Gulf coast and through Wednesday will support mainly moderate to fresh E-SE winds over the majority of the gulf. Seas will remain generally between 4 and 6 ft. Model guidance continues to indicate that a cold front will clip the northwestern gulf tonight with showers and thunderstorms. Another cold front is then expected to enter the NW Gulf by Thursday night with guidance indicating widespread showers and thunderstorms, possibly in the form of a squall line, spreading from west to east across the northern Gulf Thursday through Friday. If the squall line scenario materializes, strong southerly flow may develop early Thursday through Thursday evening to the east of the squall line over the northern Gulf, with brief gale force winds and large seas possible with the passage of the squall line. This front and associated convection will weaken as it reaches the northeastern Gulf Friday morning. A stronger cold front is forecast to sweep across the Gulf waters during the upcoming weekend. Currently, model guidance indicates that the front will enter the northwestern Gulf late Saturday night, and suggests fresh to strong southerly winds will develop ahead of the front, with strong to gale force winds behind the front on Sunday. With this scenario, wave guidance is currently forecasting a large area of seas building up to 14-17 ft across the Gulf basin behind the front. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... MODEL PREFERENCE: Global model consensus. High confidence. Strong high pressure north of the region combined with the Colombian/Panamanian low will continue to support fresh to strong NE-E winds over the majority of the Caribbean Sea, including through the Windward and Mona passages, and in the lee of Cuba through Wednesday night. Near gale force winds are expected to continue to pulse near the coast of Colombia each night during this time period, with seas up to 11 ft. The ridge north of the region will shift southeast, become elongated, and weaken later this week. This will allow for trades across the Caribbean to decrease beginning Thursday. During the upcoming weekend, winds are forecast to increase across the western Caribbean and the Yucatan Channel ahead of a cold front moving across the Gulf of Mexico. This front is currently forecast to reach the NW Caribbean late Sunday with strong winds and building seas. Over the tropical Atlantic forecast waters fresh to locally strong NE-E winds and seas of 8 ft are affecting mainly the waters north of about 15N. These marine conditions are expected to diminish through this evening. By later tonight, expect NE-E winds in the 15-20 kt range and seas of 6-7 ft. Generally tranquil conditions are then expected mid to late this week as high pressure shifts closer to the region. ...SW N ATLANTIC INCLUDING THE BAHAMAS... MODEL PREFERENCE: Global model consensus. High confidence. Fresh to strong winds on the southern periphery of Atlantic high pressure will continue south of 22N and west of 65W, including the approach to the Windward Passage, through tonight before decreasing to below 20 kt. North of 22N, gentle to moderate winds and seas of about 4 to 6 ft will prevail through Wednesday under the control of high pressure. By Thursday night, a cold front is forecast by global models to approach the northern zones, which will bring about an increase in winds and seas across the northern waters. All global model guidance has been trending deeper with this system the past 24 hours. The latest operational GFS, ECMWF, and CMC all are forecasting a period of gale force winds east of the cold front entering the northeastern zone AMZ115 early Thursday morning, then quickly shifting east of 65W by late Thursday morning. SREF and GFS ensemble probabilities also indicate at or better than 50 percent chance of gale. Based on the above trend and model support, a gale is being issued for the late Wednesday night through Thursday time frame over portions of our northern waters. A larger area of 20 to 30 kt winds will develop east of the front, north of 27N, Wednesday night and Thursday. West to northwest winds of 20 to 30 kt are expected behind this front. Seas of 8 to 13 ft will build both east and west of the front from the associated winds and from swell to the north from the parent low pressure system. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... .GMZ011...NW GULF INCLUDING STETSON BANK... GALE CONDITIONS POSSIBLE Sun into Sun night. .GMZ013...N CENTRAL GULF INCLUDING FLOWER GARDEN BANKS MARINE SANCTUARY... GALE CONDITIONS POSSIBLE Sun night. .GMZ017...W CENTRAL GULF FROM 22N TO 26N W OF 94W... GALE CONDITIONS POSSIBLE Sun into Sun night. .GMZ019...CENTRAL GULF FROM 22N TO 26N BETWEEN 87W AND 94W... GALE CONDITIONS POSSIBLE Sun night. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ115...ATLANTIC FROM 27N TO 31N BETWEEN 65W AND 70W... Gale Warning Wed night. $$ *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 Latto. National Hurricane Center.