000 AGXX40 KNHC 231815 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 215 PM EDT Sat Sep 23 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 thermal trough will develop each evening over the NW Yucatan Peninsula, move W-NW across the SW Gulf during the overnight hours and dissipate over the SW Gulf waters by late each morning. Expect the trough to be accompanied by a surge of moderate to locally fresh winds that shift from NE to SE along with brief seas to 4 ft through early Tuesday. Expect a tighter pressure gradient on Tuesday evening with a fresh to locally strong wind shift along the trough axis and seas to 6 ft through early Wednesday. Elsewhere, weak high pressure will continue to support gentle to locally moderate anticyclonic flow, and 1 to 3 ft seas, through Wednesday night. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... With Hurricane Maria over the SW N Atlantic about 275 nm E of Nassau, the gradient remains rather weak across the the Caribbean, and the tropical N Atlantic forecast waters. This supports generally light and variable winds across the basin W of 70W. The most recent scatterometer pass indicated moderate to locally fresh E-SE winds across the eastern Caribbean E of 70W while an altimeter pass provided observations of seas to near 8 ft across the Mona Passage in a southerly wind flow. These winds will persist during the weekend. Early next week, as tropical cyclone Maria continues to move northward and away from the forecast region, expect increasing trade winds of 20-25 kt and building seas to 8 ft, particularly near the Colombia and Venezuela basins. NE swell originating from the far NE Atlantic is expected to propagate through the waters E of the Tropical N Atlantic zones through Monday night, and arrive into the eastern portions of those same zones on Tuesday. ...SW N ATLANTIC INCLUDING THE BAHAMAS... Hurricane Maria is located about 275 nm E of Nassau, Bahamas at 23/1500 UTC, with maximum sustained winds 100 kt with gusts to 125 kt, and a minimum central pressure of 952 mb. Maria is moving toward the north-northwest at 7 kt, but a turn toward the north is expected by this evening. A northward motion with a decrease in forward speed is forecast to then continue through Monday. On the forecast track, Maria will move away from the Bahamas into the open waters of the western Atlantic today. The most recent scatterometer data indicated that the 20-33 kt winds extend within 360 nm NE semicircle of center. An area of moderate to fresh NE winds is noted per an ASCAT pass over the NW waters between Maria and a ridge over the SE CONUS. Mixed swell associated with Maria dominates most of the waters E of the Bahamas with seas to 8 ft acrosss the Bahamas Passages. An altimeter pass just over the center of Maria indicated max seas between 36-42 ft. Buoy 41047 located north of Maria near 27.5N71.5W is reporting seas of 24 ft while buoy 41046 located SE of Maria near 24N68W is reporting seas of 15 ft. Swells generated by Maria are increasing along portions of the southeastern United States coast and Bermuda and will be increasing along the Mid-Atlantic coast tonight and Sunday. Swells also continue to affect Puerto Rico, the Virgin Islands, the northern coast of Hispaniola, the Turks and Caicos Islands, and the Bahamas. These swells are likely to cause life- threatening surf and rip current conditions. Otherwise, in the wake of Maria a surface trough will extend from the N-central forecast waters SW to near the Central Bahamas through Wednesday night. Scattered showers and thunderstorms are possible with the trough. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... .AMZ113...ATLANTIC FROM 27N TO 31N BETWEEN 70W AND 77W... Hurricane Warning today into Sun night. .AMZ115...ATLANTIC FROM 27N TO 31N BETWEEN 65W AND 70W... Tropical Storm Warning today into tonight. .AMZ119...ATLANTIC FROM 22N TO 27N E OF BAHAMAS TO 70W... Hurricane Warning today into tonight. Tropical Storm Warning Sun. .AMZ121...ATLANTIC FROM 22N TO 27N BETWEEN 65W AND 70W... Tropical Storm Warning today into tonight. $$ *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. National Hurricane Center.