000 AGXX40 KNHC 211827 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 227 PM EDT Fri Apr 21 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... An mid to upper short wave trough is supporting clusters of showers and thunderstorms across the south central and southeast Gulf this morning, near an associated surface trough reaching from the Yucatan Channel to 25N84W. Gentle to moderate east to southeast flow is noted between the trough and weak ridging in place over north central Florida. A mid level low pressure appears to be forming along this trough currently. This may be the start of weak surface low pressure to form over the south central Gulf on Saturday that is expected to migrate to the northeast across the southern Florida peninsula through Sunday night. This will be ahead of a cold front moving off the coast of Texas late Saturday. The front is expected to weaken as it moves southeast, eventually sweeping southeast of the basin through early Tuesday. Strong northerly winds will follow the front over the far northwest and west central Gulf through Sunday with seas building to 7 ft. Otherwise, little more than a wind shift is expected as the front weakens while moving eastward. A second weak front will shift eastward over the northern Gulf Monday, followed by building high pressure behind the fronts allowing gentle breezes and slight seas early next week. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Scattered showers and thunderstorms from Jamaica to Cayman Islands to western Cuba, supported by jet dynamics aloft, will persist through Saturday then largely dissipate. Moderate to fresh trade winds over the eastern Caribbean and tropical north Atlantic west of 55W will continue into early next week south of high pressure northeast of the Bahamas. These winds will weaken into Tuesday as the high pressure dissipates. Northeast swell will move into Atlantic passages in the Leeward Islands and through the Mona Passage Saturday through early next week with seas to 7 ft. A weak cold front will move into the northwest Caribbean Monday, then stall and dissipate from central Cuba to Belize. Fresh northwest winds will follow the front, then diminish quickly through late Monday. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A ridge extends along 30N from 1021 mb high pressure located near 30N70W to northeast Florida, maintaining gentle to moderate easterly winds over most of the region. Fresh east winds are noted over the Cay Sal area of the Bahamas in a 15 UTC scatterometer pass. Seas are generally 3 to 5 ft outside of the Bahamas. Northeast swell of 5 to 7 ft will move into the region south of 27N from late Saturday through early next week. Southerly winds will increase to 15-20 kt off northeast Florida by late Sunday ahead of a cold front approaching from the west accompanied by developing low pressure moving from the eastern Gulf to off the Carolina Coast. The front is forecast to enter the forecast region by late Sunday night, and extend from 31N75W to west- central Cuba by Monday night. Strong southerly flow will develop within 240 nm east of the front Monday with seas building to 11 ft. Winds and seas diminish through early next week as the front stalls and dissipates from west of Bermuda to eastern Cuba through Tuesday. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 Christensen. National Hurricane Center.