000 AXNT20 KNHC 181802 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sun Jul 18 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 1200 UTC surface analysis and satellite imagery through 1630 UTC. ...TROPICAL WAVES... An Atlantic tropical wave is along 38W from 20N southward and moving W near 10 kt. No significant convection is associated this wave due to subsidence aloft. A Caribbean tropical wave is near 69W from the Dominican Republic southward across Venezuela and Colombia, and moving W near 20 kt. Scattered showers and isolated thunderstorms are noted over the central Caribbean basin, S Dominican Republic, W Puerto Rico and E Colombia. Another tropical wave previously located at the SW Caribbean has moved inland over Honduras and Nicaragua. It is moving W at 15 to 20 kt and should enter the E Pacific in the next 6 to 12 hours. Scattered showers and a few thunderstorms are occurring over the NW Caribbean and SE Mexican coast. A tropical wave over the Bay of Campeche and S Mexico is moving W near 10 kt. It will continue westward across S Mexico and the E Pacific. Scattered showers and thunderstorms are seen at the NW corner of the Bay of Campeche. ...MONSOON TROUGH/ITCZ... A monsoon trough stretches from the Gambian coast near 13N17W to 07N37W. Then the ITCZ extends from 07N40W to 09N55W, N of Suriname. Scattered moderate to isolated strong convection is evident 05N to 13N between the African coast and 36W. Scattered showers are present within 60 nm either side of the ITCZ, and N of Guyana. ...GULF OF MEXICO... An upper-level trough curves westward from N Florida to the central Gulf near 26N86W. Scattered moderate convection is found over the central Gulf, and near New Orleans and the Panhandle. Refer to the Tropical Waves section above for details on additional convection. Surface ridging across the N edge of the Gulf continues to support light to gentle ESE to SE winds, and seas of 2 to 4 ft across the entire Gulf. For the forecast...the Bermuda High extends a ridge westward along 30N and toward the north-central Gulf Coast. As the ridge sinks southward through Mon, tranquil conditions will prevail across the Gulf of Mexico through Thu. Moderate to fresh E winds will begin pulsing Thu to the NW of the Yucatan Peninsula. ...CARIBBEAN SEA... Scattered moderate convection is seen over Costa Rica, Panama and adjacent waters near the E end of a monsoon trough across Panama. Convergent trade winds are coupling with divergent flow aloft to trigger scattered moderate convection over and near E Cuba. Please refer to the Tropical Waves section above for details on additional convection. Fresh to strong trades and seas of 8 to 12 ft continue across the S central basin, N of Colombia and Venezuela. Moderate to locally fresh trades and seas of 5 to 7 ft prevail across the rest of the basin. For the forecast, the Bermuda High north of the area combined with lower pressure over N Colombia will support fresh to strong NE to E winds over the central Caribbean through most of the week. Expect an increase in speed and areal coverage Mon night through Wed night while reaching as far north as the Hispaniola adjacent waters. Winds near the coast of NE Colombia and the Gulf of Venezuela could pulse to strong to near gale force Wed night and Thu night. Fresh to strong E winds will occur in the afternoons and early evenings for the next several days in the Windward Passage. Fresh to strong winds are expected to pulse in the Gulf of Honduras by Wed night. ...ATLANTIC OCEAN... Enhanced by upper-level wind shear, convergent trade winds are producing scattered showers and a few thunderstorms over the SE Bahamas and N of the Leeward Islands, from 19N to 23N between 62W and 73W. Please refer to the Tropical Waves and Monsoon Trough/ITCZ sections above for details on additional convection. A persistent surface ridge across the central Atlantic basin near 33N promotes light to gentle winds and seas of 2 to 4 ft N of 24N between 31W and the Florida-Georgia coastline. Moderate to locally fresh trades and seas of 5 to 7 ft prevail from 10N to 24N between 29W and the Lesser Antilles, and near the Canarias Islands N of 25N between the NW African coast and 29W. Gentle to moderate winds with seas at 4 to 6 ft are found elsewhere. For the forecast W of 45W, fresh to strong E winds will occur in the afternoons and early evenings north of Hispaniola for the next several days. Surface ridging associated with the Bermuda High will slowly sink southward to 27N by midweek, leading toward quiescent conditions across the remainder of the western Atlantic. $$ Chan