000 AXNT20 KNHC 211727 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Jul 21 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 1700 UTC. ...SPECIAL FEATURES... Caribbean Gale Warning: The pressure gradient between the Atlantic ridge and the Colombian/Panamanian low will support gale force winds off the coast of the Colombia and in the Gulf of Venezuela tonight. Seas are forecast to build up to 10-15 ft with the strongest winds across the south-central Caribbean. For more information, please see the High Seas Forecast issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml ...TROPICAL WAVES... An Atlantic tropical wave extends its axis along 34W and south of 21N, moving west at 15 to 20 kt. Scattered moderate convection, likely enhanced by the monsoon trough, is noted from 06N to 12N between 29W and 35W. A second Atlantic tropical wave extends it axis along 51W from 20N southward, moving westward at 10 to 15 kt. No convection is noted with the wave at this time. A new tropical wave has been introduced in the E Caribbean near the Lesser Antilles along 62W from 22N southward. This wave is not producing any notable convection. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean from Senegal, extending from 14N16W to 09N42W. Segments of the ITCZ extend from 09N42W to 09N50W and from 07N54W to 08N60W. Aside from the convection described in the tropical waves section, scattered moderate convection is noted from 05N to 12N between 20W and 25W. Scattered moderate convection is also noted along the ITCZ within 80 nm of the coast of NE Venezuela and Guyana. GULF OF MEXICO... At 1500 UTC, a stationary front extends over the NW Gulf of Mexico from 30N92W to 27N97W, and is producing scattered showers. The remainder of the Gulf of Mexico is under the influence of the subtropical ridge. Gentle to locally moderate anticyclonic winds and seas from 2-4 ft prevail across the entire basin. For the forecast, the Bermuda High extends westward along 27N and towards the northeastern Gulf of Mexico. This ridge will continue to sink southward through the forecast period, providing tranquil conditions across the Gulf of Mexico for the remainder of the week. Fresh to locally strong E to SE winds will pulse nightly NW of the Yucatan Peninsula through Fri night. CARIBBEAN SEA... A Gale Warning is in effect for the south-central Caribbean. Please see the Special Features section for more details. Surface observations and recent scatterometer data depict strong to near gale force winds from the coast of Colombia north to 14N between 73W and 78W, with seas of 8-15 ft. Elsewhere in the basin, moderate to fresh trades prevail with 5-8 ft seas, except in the NW Caribbean where trades are mainly moderate with seas of 3-5 ft. For the forecast, the Bermuda High north of the area combined with low pressure N Colombia will continue to support fresh to strong E winds over the central Caribbean. Gale force winds will pulse tonight north of Colombia and the Gulf of Venezuela. Fresh to strong winds will continue across the central Caribbean through Fri, reaching as far north as Hispaniola adjacent waters. Fresh to strong E winds will occur in the afternoons and early evenings in the Windward Passage through Fri. Fresh to strong winds are expected to pulse in the Gulf of Honduras tonight and Thu night. ATLANTIC OCEAN... Gentle to moderate anticyclonic winds prevail across the basin, anchored by a 1026 mb high pressure near 33N48W and another 1026 mb high pressure near 36N41W. Fresh to strong northerly winds are noted near the coast of Morocco. Fresh to strong NNE winds were detected by the latest scatterometer pass near the Canary Islands. Seas are 3-5 ft in the W Atlantic north of 20N west of 65W, with 5-8 ft seas elsewhere in the discussion waters. For the forecast W of 65W, fresh to strong E winds will pulse in the afternoons and evenings north of Hispaniola through Fri. Moderate to fresh trades will prevail elsewhere south of 20N. Surface ridging associated with the Bermuda High will prevail along 27N, leading toward quiescent conditions across the remainder of the western Atlantic. $$ Mahoney/SDR/HN