055 AGXX40 KNHC 280711 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 311 AM EDT Sat Jul 28 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... The Atlantic sub-tropical ridge has an axis that extends southwestward across the Florida peninsula and across the eastern part of the gulf to a 1018 mb high center analyzed at 27N85.5W. The associated gradient is allowing for light to gentle anticyclonic winds to exist throughout, except for light and variable winds near the high center. The buoy observations along with recent satellite-derived waveheight data reveal seas in the 0-2 ft range over just about the entire basin, except for slightly higher seas of 2-3 ft in the eastern Bay of Campeche related to the gradient near the daily Yucatan Peninsula thermal trough. This trough will continue to emerge off the western Yucatan Peninsula each night and move across the eastern Bay of Campeche during the during the forecast period, with associated winds increasing to locally fresh near the trough. Seas will build a little higher over the eastern Bay of Campeche, to the range of 3-4 ft, beginning Mon night. The weak high pressure currently in place will change very little through the middle part of next week. So very little changes are expected with the current observed conditions. A cold front will approach the far northwestern gulf Tue, and move across those waters Wed. Model guidance indicates the front will be driven by yet another rather strong deep- layer trough for this time of year that will swing east-southeast from the Great Plains to the southeastern United States at that time. Expect scattered showers and thunderstorms, some with gusty winds and slightly higher seas, to increase over the northwestern section of the gulf Tue through Wed night as the front moves across those waters. Isolated showers and thunderstorms may occur elsewhere over the gulf through Wed. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Shallow moisture in the northwestern Caribbean along with divergent flow aloft combined with energy from a tropical wave along 81W earlier supported scattered to numerous showers and thunderstorms over and near central Cuba. These ingredients are presently helping to sustain scattered showers and thunderstorms north of 20N between 80-85W. Expect for this activity to decrease through Sun as the wave pulls further away as it moves across inland across Central America. The eastern segment of the E Pacific monsoon trough in combination with southern part of the tropical wave along 81W continues to support scattered showers and tstms south of about 13N and west of NW Colombia to over much of Costa Rica and northern Panama. Isolated showers and thunderstorms are noted over far north-central Caribbean and over southern Hispaniola, supported by diffluence aloft associated with an upper level low centered just to the NW of the Dominican Republic. A tropical wave just west of the Lesser Antilles early this morning will move across the eastern Caribbean through Sun evening, then across the central Caribbean through the middle part of the upcoming week. With the aforementioned upper-level low forecast to slide west- southwestward across the north- central Caribbean at that time, expect for scattered showers and thunderstorms to possibly increase over those waters as the wave passes through. Strong northeast to east winds will pulse along the coast of NW Colombia and NW Venezuela each night through Tue night, then mainly fresh winds with locally strong winds on Wed. Fresh trade winds will prevail elsewhere across the central Caribbean, with moderate to fresh east winds over the eastern Caribbean, and gentle to moderate east-southeast winds over the western Caribbean. East winds will pulse to strong intensity over the Gulf of Honduras starting Mon. ...SW N ATLANTIC INCLUDING THE BAHAMAS... Diffluent flow aloft between the base of an upper trough over the southeastern United States and high pressure ridging just to the NE of the northern Bahamas continues to support scattered showers and thunderstorms north of about 22N and west of 70W. The upper-level trough will gradually shift eastward through today and weaken. It will provide enough lift to continue to support the shower and thunderstorm activity over that area of the basin. Farther east, an upper-level low just to the northwest of the Dominican Republic supports scattered showers and isolated thunderstorms from 19N-27N between 65W-73W. This feature will move slowly west-southwestward through the next few days. Otherwise, high pressure over the west-central Atlantic will prevail across the region through Wed night. Fresh to occasionally strong trade winds are expected just N of Hispaniola through Wed. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... None. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 Aguirre. National Hurricane Center.