000 AGXX40 KNHC 220639 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 239 AM EDT Tue May 22 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... A sharp upper trough persists over the eastern Gulf this morning from the western Florida Panhandle to near the Yucatan Channel. An associated surface trough is analyzed directly beneath the near stationary trough. Divergent flow aloft is supporting a few showers and thunderstorms along 23N/24N east of 90W to the Straits of Florida. The trough interrupts a broad surface ridge reaching across the northern Gulf and Deep South states. Gentle to moderate E to SE winds are evident across the Gulf as noted in buoy observations and scatterometer satellite data. Buoys and altimeter satellite data show generally 2 to 4 ft seas. No other showers or thunderstorms are noted. The ridge over the northern Gulf coast will shift east through mid week ahead of a developing low pressure area expected to emerge off the coast of Yucatan Thu. The low pressure will continue to move northward into the north central Gulf through Sat, bringing fresh to strong winds and building seas to the eastern Gulf, then diminish Sun as the low moves north of the area. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... The southern end of a sharp upper trough reaches from the Yucatan Channel to near Cabo Gracias a Dios in eastern Honduras/northeast Nicaragua. A related surface trough reaches from central Honduras to near Cozumel Island. Deep layer tropical moisture continues to stream northward on the eastern edge of this trough, where related upper divergence is supporting clusters of showers and thunderstorms from just north of San Andres Island to just south of Grand Cayman Island. A recent scatterometer satellite pass indicated fresh to strong SE winds from 15N to 20N east of the trough to 80W. Meanwhile Atlantic ridging north of the area is supporting moderate to fresh trade winds from the tropical north Atlantic west of 55W to the central Caribbean, except for fresh to strong winds funneling along the higher coastal terrain of northeast Colombia and northwest Venezuela. Trade wind convergence, possibly aided by the upper trough is supporting scattered convection from the central coast of Colombia to near 13N77W. Meanwhile a weak tropical wave over the far eastern Caribbean is starting to lose definition as it drifts west, and will likely dissipate. A line of showers and thunderstorms is active from near Guadeloupe to 18N55W, at the base of broad upper low centered north of the area. Buoy observations and altimeter data show5 to 7 ft seas in the northwest Caribbean, 6 to 8 ft seas over the central Caribbean, and 4 to 6 ft seas in the eastern Caribbean, and 5 to 7 ft seas elsewhere. The Atlantic ridge will maintain fresh to locally strong trades over the central Caribbean through Fri. Strong winds and seas to 9 ft will affect the NW coast of Colombia. Low pressure may form along the trough in the northwest Caribbean and near the Yucatan Peninsula through mid week, then move north into the Gulf of Mexico late Thu. Fresh to strong winds will develop between the trough and the Atlantic high pressure south of Cuba Fri, persisting through Sat. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A recent scatterometer satellite pass indicated fresh to strong trade winds pulsing off the north coast of Haiti. The stronger winds are due to localized overnight land breezes off the coast, and relatively tight gradient south of the subtropical ridge, reaching east to west along 30N. Otherwise, the ridge is supporting gentle to moderate SE winds north of 22N and moderate to fresh trade winds south of 22N. Seas are 4 to 6 ft in open waters. The ridge will shift eastward from mid to late week, as developing low pressure moves through the Gulf of Mexico west of the region. This change in the pattern will result in slightly stronger winds over the Cay Sal Bank area, and SE to S winds increasing over the northern Bahamas and off northeast Florida Sat. Winds and seas will diminish elsewhere due to a weakened and displaced Atlantic ridge. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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.