000 AXNT20 KNHC 120552 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 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 0000 UTC surface analysis and satellite imagery through 0430 UTC. ...TROPICAL WAVES... An Atlantic tropical wave is along 33W from 12N southward and moving W at 15 to 20 kt. Scattered moderate convection is seen from 07N to 12N between 29W and 36W. Another weaker Atlantic tropical wave is near 45W from 10N southward and moving W near 15 kt. No significant convection is found near this wave. A robust Caribbean tropical wave is along 70W from 22N southward across Hispaniola to N Venezuela, and moving W at 10 to 15 kt. Aided by upper-level divergent winds, scattered to numerous showers and thunderstorms are present across the SE Bahamas, Dominican Republic and the NE Caribbean Basin. Another Caribbean tropical wave over Honduras, Nicaragua and Costa Rica is moving W at 10 to 15 kt. Scattered showers are occurring along the coastal waters of the above countries. This wave is entering the E Pacific and will be included in the Pacific Discussion. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the African coast near the Gambia/Guinea-Bissau border at 12N16W to 08N26W to 07N38W. Segments of the ITCZ then continues from 07N39W to 07N45W, and from 07N47W to 07N51W, NE of the French Giana. Scattered moderate to isolated strong convection are evident near the monsoon trough between 05N and 14N from the African coast to 29W. Scattered showers are found near the ITCZ between 07N and 10N from 37W to the French Giana coastline. ...GULF OF MEXICO... A surface ridge extends west-southwestward from N Florida across the N Gulf to S Texas. An upper-level trough is also across the N Gulf near 29N. Convergent SE to S winds along the ridge axis are coupling with the low to trigger scattered showers and thunderstorms near New Orleans within 55 nm of 29N88W. Otherwise, light to gentle winds and seas of 1 to 3 ft prevail across the N Gulf. A surface trough is exiting into the SW Gulf near the Yucatan Peninsular, numerous showers and thunderstorms are occurring over the SE Bay of Campeche. Increased pressure gradient between this trough and the ridge to the N is creating moderate to fresh winds, and seas of 4 to 6 ft over the SW Gulf. Gentle to moderate ESE winds and seas of 2 to 4 ft prevail elsewhere. For the forecast, moderate SE winds persist over the western Gulf between a ridge extending from the western Atlantic to the north central Gulf and lower pressure over northern Mexico. The ridge will lift just 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 Tropical Waves section above for details on convection in the basin. Scatterometer data depicts fresh to locally strong trade winds across the central S and SW Caribbean Basin. Model guidance and earlier satellite altimetry data suggest seas are between 7 and 9 ft in this area. Moderate to fresh trades and seas of 4 to 6 ft are present over the E and central N basin. Gentle to moderate winds and seas of 3 to 5 ft prevail elsewhere. For the forecast, a large tropical wave reaching from Hispaniola to northwest Venezuela will move quickly across the central Caribbean tonight through Tue, and then move west of the basin on Wed. 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 Tropical Waves and Monsoon Trough/ITCZ sections above for information on convection across the basin. There are two upper-level lows, one over the N Bahamas at 26N78W and another one ESE of Bermuda at 31N52W. Scattered showers and a few thunderstorms are occurring over S Florida and the N Bahamas from 21N to 29N between 72W and 81W, and over the central Atlantic N of 28N between 47W and 56W. A surface ridge extends west-southwestward from a 1030 mb high near 37N48W to N Florida. Light to gentle winds and seas of 3 to 5 ft prevail near this feature N of 26N from 44W to Florida-Georgia coast. Moderate to fresh trades and seas of 6 to 8 ft are seen between 10N and 26N from 39W to the Bahamas and Less Antilles. Moderate to locally fresh trades and seas of 4 to 7 ft are found farther E, N of 22N from the Cape Verde Islands to 40W. Gentle to moderate SE to S trades and seas of 4 to 6 ft prevail elsewhere. For the forecast west of 65W, a surface ridge from the N central Atlc through Bermuda to central Florida will lift north to along 32N through Tue. A large tropical wave over Hispaniola will move quickly across the central Caribbean and bring a surge in wind and waves to the Atlantic waters north of Hispaniola and across the Turks and Caicos Islands and southern Bahamas late Mon and Tue. Strong winds will continue to pulse off Hispaniola and into the Windward Passage Tue night into Wed. Winds and seas will diminish across the region later in the week as high pressure builds in the wake of the tropical wave. $$ Chan