217 AGXX40 KNHC 041800 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 200 PM EDT Thu Oct 4 2018 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... Scattered showers and isolated thunderstorms are moving westward over the northern Gulf from 25N-30N between 87W-92W. This activity is being enhanced by an area of upper-level diffluence over the Gulf stemming from an upper-level ridge over the south-central U.S. GOES-16 TPW imagery shows that the highest moisture in the area is near 90W-92W moving westward. These showers and storms should diminish before reaching 94W as they encounter increasingly pronounced low and mid level ridging. A surface trough is analyzed over the central Bay of Campeche. Scattered showers and isolated thunderstorms are noted west of the trough, just offshore the coast of Mexico between Veracruz and Tampico. High pressure will prevail over the forecast area through the weekend. A surface trough will develop each evening over the Yucatan peninsula. The trough will move into the SW Gulf overnight, where it will dissipate each morning. Moderate to fresh winds will accompany the trough. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... A large cyclonic gyre, defined by a broad area of low pressure, covers a portion of Central America and the western Caribbean Sea. Within this gyre, a surface trough is analyzed from 20N80W to a 1007 mb low near 16N83W to 11N83W. Satellite imagery shows scattered moderate to isolated strong convection from 11N-16N between 75W-82W. Scattered showers and thunderstorms are noted elsewhere from 11N-18N between 70W-85W. Some slow development of this system is possible this weekend or early next week as the system drifts northwestward across the northwestern Caribbean Sea and the southern Gulf of Mexico. A mid to upper level trough extending over the Bahamas and Greater Antilles will help advect moisture northwestward over the next several days. As a result, heavy rainfall is likely to spread over portions of Hispaniola, Jamaica, Cuba, the Yucatan Peninsula, and Central America Friday through early next week. A tropical wave is over the eastern Caribbean. Refer to the Tropical Waves section above for details. Large NNE swell generated from Hurricane Leslie will continue to pass through the Atlantic passages into the Caribbean through the end of the week before subsiding. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A weak surface trough located near the east coast of South Florida is enhancing coverage of showers and thunderstorms over the NW Bahamas and the southern and central Florida peninsula. This activity should continue through this afternoon as the trough drifts westward. Hurricane Leslie centered near 32.5N 57.2W at 04/1500 UTC moving N at 8 kt. Leslie will continue to lift slowly northward through Fri. Large and powerful swell generated by Leslie will affect the forecast waters through the end of the week. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 Latto. National Hurricane Center.