000 AGXX40 KNHC 121800 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 200 PM EDT Fri May 12 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... The high that was over the NE Gulf has merged with a ridge extending W from the Atlantic through the Florida Straits. Light to moderate SE to S winds are noted over most of the Gulf in advance of a cold front that is just entering the NW Gulf from Texas. The front entering the Gulf has weakened ridging out ahead of it and has reduced the pressure gradient over the Bay of Campeche. The cold front will head SE over the Northern Gulf this evening through Sunday. The southern portion of the front will stall over the SW Gulf and the northern portion will stall over Florida. Both portions of the front will weaken by Monday. High pressure will then build over the Gulf in the wake of the front on Sunday and Monday, then shift eastward into the Atlantic on Tuesday and Wednesday. This will set up return flow over the Western Gulf. The return flow could become Strong by Thursday ahead of yet another frontal boundary pushing into the Southern Plains. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... High pressure centered just east of the Bahamas near 23N71W is maintaining moderate E to NE trades over the Eastern Caribbean and moderate E to SE winds over the Western Caribbean. A surface trough still extends from the Atlantic into the extreme NE Caribbean. However, the surface trough has begun to weaken. The showers and thunderstorms that were present over and east of the Virgin Islands have shifted eastward away from the trough into the open Atlantic in tandem with the associated upper-level trough. A tropical wave is just E of the Southern Windward Islands near 60W. The tropical wave continues enhancing the pressure gradient over the Tropical Atlantic to the E of the Windward Islands. As the wave shifts W into the Caribbean, the gradient over the Tropical N Atlantic will lessen and allow winds and seas to subside. However, long period N to NE swell will maintain combined seas between 8 and 9 ft in this area until Saturday Morning. Model guidance suggests the tropical wave will continue tracking W through the Caribbean and could become an area of low pressure on Monday or Tuesday. ...SW N ATLANTIC INCLUDING THE BAHAMAS... An cold front situated well to the E of the Bahamas from 31N51W to 25N59W will dissipate this evening. A new cold front is being dragged SE be developing low pressure that is centered N of Bermuda near 33N65W. Strong SW winds can be expected ahead of the front, generally to the N of 26N as it progresses eastward through Sunday. NW swell generated on the N side of the front will cause combined seas to build as high as 12 feet along 31N as the front moves E. Another cold front will be heading eastward very slowly across the northern waters on Saturday night through Monday night, but this boundary looks weaker. SW winds ahead of this front and N of 30N will be fresh to strong from Saturday afternoon through Sunday evening, then will weaken as the front loses impetus. Winds behind the front will be mainly gentle as weak high pressure passes to the N of the Bahamas near 30N. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 McElroy. National Hurricane Center.