000 AGXX40 KNHC 181711 MIMATS Marine Weather Discussion NWS National Hurricane Center Miami FL 111 PM EDT Fri Aug 18 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... High pressure is centered in the N central Gulf near 28N90W with a ridge extending from E to W. Latest observations show light to moderate anticyclonic flow across the basin, except locally to moderate. Seas are 1 to 3 ft, highest in the western Gulf. An upper level low approaching the Straits of Florida is supporting scattered showers and isolated thunderstorms in the eastern Gulf. The upper level low will continue to move WNW while the northern extent of a tropical wave, currently moving through the SE Bahamas, approaches the basin. The tropical wave will enter the SE Gulf Saturday night, moving across the basin through early next week. Meanwhile, Tropical Storm Harvey currently well SE of the area entering the eastern Caribbean is forecast to approach the NW Caribbean and Yucatan Peninsula Tue into Tue night. Uncertainty remains as far as the exact strength and track of Harvey that late in the forecast period. Tropical Storm Conditions are Possible in the SW Gulf Tue. Please refer to http://hurricanes.gov for more information on Harvey. ...CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... Tropical Storm Harvey is in the process of entering the eastern Caribbean, centered near 13 nm SSW of St. Vincent and 43 nm SSW of St. Luica. Maximum sustained winds are 35 kt with gusts to 45 kt. Minimum central pressure is 1005 mb. Numerous showers and scattered thunderstorms are within 240 nm in the SW semicircle of Harvey. Harvey is expected to continue westward across the central Caribbean through Sun, moving into the western Caribbean early next week. Harvey is forecast to move into the NW Caribbean and approach the Yucatan Peninsula Tue and Tue night, although uncertainty remains with respect to the strength and exact track of Harvey that late in the forecast period. Harvey will remain a relatively compact system, with an envelope of strong winds and seas 8 to 12 ft within 120 nm of the center on the northern semicircle. Please refer to http://hurricanes.gov for more information on Harvey. Ahead of Harvey, a tropical wave currently moving across eastern Cuba and across the waters between Jamaica and Haiti to NW Colombia will follow an upper low across the western Caribbean through Sat, accompanied by a few showers and thunderstorms across mainly the northwest Caribbean. Associated convection is currently ongoing across the approach to the Windward Passage. ...SW N ATLANTIC INCLUDING THE BAHAMAS... A large and well defined upper low centered over central Cuba and moving into the Straits of Florida is moving WNW and is supporting isolated convection over portions of the Bahamas and eastern Cuba. The northern extent of a tropical wave is moving through the SE Bahamas in the wake of the upper level low. Fresh easterly winds follow the tropical wave over the waters S of 22N and W of 70W. Meanwhile, a ridge extends along roughly 29N. Fresh easterly winds will expand across the waters S of 25N with locally stronger winds near the coast of Hispaniola through today into Sat as Tropical Storm Harvey passes S of the region through early next week. A second feature, an area of low pressure to the SE approaching the tropical N Atlantic, is moving WNW toward the region. Some potential exists for this low to develop into a tropical cyclone during the next couple of days as it approaches the area. Strong upper level winds may weaken it before it crosses 65W to the N of Puerto Rico by early Sun. Even so, the low will bring strong winds and building seas to the area S of 25N from Sun through mid week. The ridge along roughly 29N will move little through Sun, then will shift slowly northward early next week, maintaining light to gentle breezes into early next week N of 28N, with short period southeast swell of 4 to 6 ft. $$ .WARNINGS...Any changes impacting coastal NWS offices will be coordinated through AWIPS II Collaboration Chat, or by telephone: .GULF OF MEXICO... None. .CARIBBEAN SEA AND TROPICAL N ATLANTIC FROM 07N TO 19N BETWEEN 55W AND 64W... .AMZ021...CARIBBEAN FROM 15N TO 18N BETWEEN 72W AND 80W... Tropical Storm Warning Sat night into Sun. .AMZ031...CARIBBEAN FROM 11N TO 15N BETWEEN 72W AND 80W INCLUDING COLOMBIA BASIN... Tropical Storm Warning Sat night into Sun. .AMZ033...CARIBBEAN S OF 15N BETWEEN 64W AND 72W INCLUDING VENEZUELA BASIN... Tropical Storm Warning tonight into Sat night. .AMZ035...OFFSHORE WATERS WINDWARD ISLANDS INCLUDING TRINIDAD AND TOBAGO... Tropical Storm Warning today into tonight. .SW N ATLANTIC INCLUDING THE BAHAMAS... None. $$ *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 Lewitsky. National Hurricane Center.