000 AGXX40 KNHC 290654 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 254 AM EDT Fri Sep 29 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 stationary front extends from the Florida Panhandle to across SE Louisiana to the upper Texas coast. A weak area of low pressure is analyzed in the SW Gulf near 19.5N93W. Broad troughing is present in the SE Gulf across the Straits of Florida. Mainly moderate winds and seas of 2 to 4 ft dominate the SW half of the basin, with gentle easterly winds and seas of 2 ft or less across the NE half of the basin. Meanwhile, an upper level low across the eastern Gulf, a tropical wave across the Yucatan Peninsula and additional tropical moisture continues to support a fairly unstable atmosphere across the basin, with scattered showers and isolated thunderstorms. The front is forecast to sag to the SE and S through the upcoming weekend, while weak low pressure may very briefly develop along it in the E central Gulf. Building high pressure N of the front will help to increase NE to E flow to fresh to strong Sat night through Sun night. The front will wash out into early next week with moderate to locally fresh winds for Mon and Mon night. High pressure will strengthen thereafter, increasing easterly flow back to fresh to strong in the eastern Gulf by early Tue, spreading westward to the central Gulf by mid-week. Seas will build significantly with the increasing winds, reaching 7 to 10 ft across the central and eastern Gulf by early Wed. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... The combination of tropical wave energy over central America and upper level diffluence over the northwestern Caribbean continues to support clusters of convection over the northwestern Caribbean. A tropical wave is analyzed in the eastern Caribbean along 63W, while a sharp upper level trough is just to the W extending S from the Mona passage. These features are supporting scattered showers and isolated thunderstorms across the eastern Caribbean islands. Moderate to fresh trades and 4 to 7 ft seas dominate the basin, except in the SW Caribbean where the monsoon trough lifts from the NW coast of Colombia to eastern Nicaragua, with light and variable winds S of the monsoon trough. Scattered thunderstorms are also occurring along the monsoon trough. Moderate to locally fresh trades will prevail through the upcoming weekend and early next week, with mainly 4 to 7 ft seas. The monsoon trough will remain oriented from its current location with active convection along it, as well as in the NW Caribbean, where plentiful tropical moisture will continue to accumulate as the tropical wave moves into the area. ...SW N ATLANTIC INCLUDING THE BAHAMAS... Broad surface troughing extends from near 31N68W to just N of the northern Bahamas to near the Florida Treasure Coast. Plentiful moisture is currently in place along and S of the trough. Additional convection is over the SE waters due to a sharp upper level trough and the northern extent of a tropical wave analyzed across the NE Caribbean islands. Mainly light winds are present N of 26N W of 70W with moderate to fresh winds elsewhere. Seas are 7 to 10 ft N of 26N E of 75W in northerly swell associated with distant Tropical Storm Maria, with mainly 4 to 6 ft seas elsewhere. Broad and week low pressure may develop along this trough over the gulf stream with a medium chance of tropical cyclone development during the next 5 days. Fresh to strong winds will setup on the eastern side of the low, while a cold front will sneak into the NW waters on the back side of the low with fresh to strong NE flow behind it from the Georgia coast southward. That boundary will stall along 30N through the upcoming weekend, gradually washing out Sun night. High pressure N of the area will strengthen and build down with fresh to strong easterly flow dominating N of 23N and W of 75W for early next week, with moderate to fresh trades elsewhere. Seas will build to 7 to 10 ft with the fresh to strong wind areas. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.