000 AXNT20 KNHC 111056 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sun Jul 11 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 0600 UTC surface analysis and satellite imagery through 1040 UTC. ...TROPICAL WAVES... An Atlantic tropical wave is near 24W/25W from 12N southward and moving W at 10 to 15 kt. Scattered moderate convection is from 05N to 06N between 24W and 26W. Another Atlantic tropical wave is along 39W/40W from 09N southward and moving W at 10 to 15 kt. No significant convection is noted with this wave. A Caribbean tropical wave is near 64W from 21N southward moving W 15 to 20 kt. Aided by divergent upper-level winds aloft, scattered moderate to isolated strong convection is present within 150 nm west of the tropical wave axis, north of 14N. Scattered moderate convection is also noted from 08N to 13N between 55W and 62W. Another Caribbean tropical wave is along 80W from 15N southward to central Panama, moving W at 15 kt. Scattered moderate to isolated strong convection is flaring up over the SW Caribbean basin from 10N to 15N W of 77W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from Senegal near 15N16W to 09N25W to 07N35W. Segments of the ITCZ extend from 07N35W to 06N39W, and from 06N41W to 04N51W near the French Guiana- Brazil border. Scattered moderate to isolated strong convection is evident from 08N to 11N east of 17W to the coast of Africa, from 07N to 09N between 28W and 31W, and from 08N to 10N between 45W and 52W. GULF OF MEXICO... A surface ridge extends westward from the western Atlantic across the northern Gulf to South Texas. Divergent upper- level winds are coupling with convergent SE winds along the surface ridge to trigger scattered convection over the north-central Gulf. A recent scatterometer satellite pass indicated moderate to fresh NE winds off the western coast of the Yucatan Peninsula, where a surface trough developed overnight. Fresh NE to E winds are also noted in the Straits of Florida. Gentle to moderate E to SE winds are noted elsewhere. Seas are 2 to 4 ft in most areas, slightly higher over the Bay of Campeche. 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 see the Tropical Wave section for information on convection. Fresh to strong trade winds and 8 to 10 ft seas are noted across the central Caribbean, driven by the pressure gradient between the subtropical high north of the area and lower pressure over Colombia and W Venezuela. Fresh NE winds and 6 ft seas are noted in the Gulf of Honduras. In the eastern Caribbean, mainly moderate trades and seas of 5 to 7 ft are evident. Gentle to moderate trades and seas of 4 to 6 ft are found elsewhere. For the forecast, the tropical wave in the eastern Caribbean will move through the central Caribbean by late Mon or early Tue, and then west of the basin through mid week. High pressure centered north of the region will build in the wake of the tropical wave, supporting strong tradewinds and building seas into Wed, to include strong NE winds across the Windward Passage 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 ridge extends from near Bermuda to central Florida. The gradient between this ridge and a tropical wave over the eastern Caribbean is supporting moderate fresh trade winds south of 25N west of 35W, with 6 to 8 ft seas in open waters. Gentle to moderate E to SE winds are noted along the ridge axis, north of 25N, with 3 to 5 ft seas in open waters. An upper low centered just east of the central Bahamas is supporting scattered showers and thunderstorms near the approaches to the Windward Passage, and north of the Leeward Islands where the tropical wave is present. A few showers and thunderstorms is noted off northeast Florida over the Gulf Stream. 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 from Bermuda to central Florida will lift north of the area through tonight. A large tropical wave moving across the eastern Caribbean will bring a surge in wind and waves to the Atlantic waters north Leeward Islands today, north of Puerto Rico and Hispaniola 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. $$ Christensen