000 AGXX40 KNHC 201747 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 1247 PM EST Mon Nov 20 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 strong cold front crosses the southern Gulf of Mexico from the Florida Straits to 22N90W. From that point, it becomes stationary and extends over the Bay of Campeche. Gentle to moderate easterly winds prevail across the basin. The front is slowing down and will stall and weaken over the southern Gulf through Tuesday. High pressure over Texas will shift rapidly eastward through the Carolinas by Tue evening, allowing the winds and seas over the Gulf to diminish. A surface trough is expected to develop on Tue over the eastern Gulf as a sharp upper-level trough digs into the lower Mississippi Valley and central Gulf. A reinforcing upper- level disturbance will move into the western Gulf by Wed, causing the trough to deepen into a low pressure area, as well as ushering in another frontal boundary and round of strong northerly winds over the western Gulf late Wed into Thu. Model guidance has come into better agreement on the likelihood of gales off the coast of Mexico during that time frame, so the official forecast calls for a minimal gale force event along the Mexican coast near Veracruz. The low pressure over the eastern Gulf will slowly lift NE across Florida on Thu and allow the frontal boundary to exit the SE Gulf by Fri night. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... A 1008 mb surface low persists over the central Caribbean near 14N77W. Troughing extending NE from the low continues to support scattered showers and thunderstorms over the north-central Caribbean affecting western Puerto Rico and adjacent waters south of Dominican Republic. Moderate to fresh NE to E prevail over the basin except in the vicinity of the monsoon trough over the SW Caribbean. Winds will diminish over the region as high pressure north of the area weakens in response to the developing low pressure along the east coast of the United States. Seas will generally run 2 to 4 ft during the next several days. The weak pressure gradient should remain in place over the Caribbean until Thu, when a cold front will enter the NW Caribbean from the Gulf of Mexico. The front will then stall and weaken over the NW Caribbean Fri. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A cold front extends from 31N68W to the Florida Straits. Fresh to strong SW winds are straddling 30N between the front and 66W. Fresh winds prevail in the vicinity of the front mainly west of 67W. Elsewhere a ridge extends from high pressure over the central Atlantic to east of the central Bahamas near 24N71W, while a weak pre-frontal trough crosses the waters northeast of the central Bahamas. The pressure gradient along the southern flank of the ridge is generally maintaining moderate winds and 5 to 7 ft seas in NE swell over the forecast waters S of 25N. Winds and seas will increase over the northern Bahamas tonight and Tue as the cold front stalls over the central Bahamas and high pressure builds eastward from the United States east coast. The front will eventually lift northward through mid week. A second front will move off the NE Florida coast Wed, associated with a low pressure area moving from the eastern Gulf NE across northern Florida to off the Carolinas through Fri. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... .GMZ023...SW GULF S OF 22N W OF 94W... GALE CONDITIONS POSSIBLE Wed into Wed night. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 ERA. National Hurricane Center.