000 AXNT20 KNHC 112319 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Mon Jul 12 2021 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...TROPICAL WAVES... An Atlantic tropical wave extends its axis along 30W from 12N southward, moving west at 10 to 15 kt. Scattered showers prevail from 07N-11N between 28W-34W. Another Atlantic tropical wave extends its axis along 43W from 10N southward and moving W at 10 to 15 kt. No significant convection is noted with this wave at this time. A Caribbean tropical wave extends its axis along 67W from 21N southward, moving W at 10 to 15 kt. Scattered moderate convection is present from 12N to 22N between 60W and 72W. The northern extension of a tropical wave is analyzed with axis along 83W and south of 15N, moving west at around 10 kt. Scattered moderate convection is noted south of 17N between 80W and 88W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Guinea-Bissau near 12N17W to 08N36W. Segments of the ITCZ extend from 08N36W to 08N41W, and from 09N43W to 09N50W. Scattered moderate convection associated with the monsoon trough is from 06N to 13N and east of 28W. GULF OF MEXICO... A surface ridge extends westward from the western Atlantic across the basin. The periphery of an upper-level low centered over the Bahamas extends over the Florida peninsula and eastern Gulf enhancing convection mainly east of 83W. Latest scatterometer data depicts gentle to moderate easterly winds across the Florida Straits and far east Gulf waters, while light to gentle anticyclonic winds prevail west of 84W. Seas are 1 to 2 ft in the northeast part of the basin with 3 to 5 ft seas elsewhere. For the forecast, the ridge will lift north of the area through Mon. This will support gentle to moderate winds and slight to moderate seas through mid week. The exception will be fresh to occasionally strong winds off the northwest Yucatan Peninsula and eastern Bay of Campeche during overnight hours through mid week, related to the surface trough that forms during the late afternoon each day. CARIBBEAN SEA... Please refer to the section above for details on the tropical waves moving across the basin. Scatterometer data depicts fresh to strong trade winds prevailing across most of the basin except over the northwest portion, where gentle to moderate easterlies are noted. Seas range from 6 to 10 ft except in the far SE Caribbean, where seas are 3 to 5 ft. Seas of 2 to 4 ft are within the northwestern portion of the basin, including the Gulf of Honduras. For the forecast, the tropical wave across the E Caribbean will move quickly across the central Caribbean tonight through Tue, and then move west of the basin on Wed enhancing convection. High pressure centered north of the region will build in the wake of the tropical wave, supporting strong tradewinds and building seas into Wed, including strong nocturnal NE winds across the Windward Passage tonight through Tue night. Winds and seas will diminish through late Thu. ATLANTIC OCEAN... Please see the section above for information the tropical waves moving across the basin. A surface high centered near 36N50W supports gentle to moderate anticyclonic flow across the basin north of 25N and west of 40W with 3 to 5 ft seas. An upper low centered just over the Bahamas is supporting scattered showers and thunderstorms across the western Atlantic mainly west of 73W. The gradient between the surface ridge extending from near Bermuda to central Florida and a tropical wave over the eastern Caribbean supports moderate to fresh trade winds south of 25N west of 35W, with 6 to 8 ft seas in open waters. Moderate to fresh NE winds and 5 to 7 ft seas are noted east of 35W. For the forecast west of 65W, the surface ridge will lift north to along 32N tonight through Tue. A large tropical wave moving quickly across the eastern Caribbean will bring a surge in wind and waves to the Atlantic waters north of Leeward Islands and Puerto Rico through tonight, north of Hispaniola tonight through Mon, then across the Turks and Caicos Islands and southern Bahamas late Mon and Tue. Winds and seas will diminish across the region by mid week as high pressure builds across the region in the wake of the tropical wave. $$ ERA