Atlantic Tropical Weather Discussion
621 AXNT20 KNHC 290421 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0615 UTC Sat Aug 29 2026 Tropical Weather Discussion for North America, Central America Gulf of America, 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 0400 UTC. ...SPECIAL FEATURES... Atlantic Gale Warning: The remnants of Tropical Storm Dolly have opened up into a trough at the surface, and is now a tropical wave along about 51W. This system is passing directly south of the Atlantic subtropical ridge, and producing gale-force winds to 35 kt, from 16.5N to 17.5N between 49W and 51W. Peaks seas there are estimated at 14 ft. This tropical wave will approach the waters east of the Leeward Islands late Sat as a strong tropical wave, with winds expected to diminish to 25-30 kt by then, and below gale conditions. Strong winds with gusts to gale- force, rough seas, accompanied by squalls and thunderstorms will spread into the far NE Caribbean, the Virgin Islands, and Puerto Rico and the adjacent waters Sat evening into early next week in association with this tropical wave. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml ...TROPICAL WAVES... A tropical wave is along 30W, south of 16N, moving westward at around 15 kt. Isolated moderate convection is around the periphery of this wave, as Saharan Air dominates the area N of 11N. A tropical wave, the remnants of Dolly, is along 50W, south of 21N, moving westward around 20 kt. A few clusters of moderate to strong convection are noted from 15N to 19N between 49.5W and 53.5W. Gale-force winds accompany this wave. See description above in the Special Features section for more details. A tropical wave is over the eastern Caribbean, along 64W and south of 17N, moving westward at 15 to 20 kt. Scattered moderate convection is noted from 13.5N to 17N between 63W and 65W. A tropical wave is over the central Caribbean with axis near 79W, moving westward at 15 to 20 kt. The wave appears to be enhancing convection over parts of central and eastern Cuba and Jamaica. Scattered moderate isolated strong convection is near the south portion of this wave from 09N to 11.5N between 78W and 83W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Mauritania near 19.5N16.5W to 10N20W to 07N26W. The ITCZ extends from 06N34W to 15N50W, then resumes from 11N54W to 09.5N61W. Associated convection is described above with the tropical waves. ...GULF OF AMERICA... Showers and thunderstorms affecting the norther Gulf waters N of 26N have diminished significantly in recent hours, with only widely scattered moderate convection now occurring mainly N of 26N and E of 91W. This activity is occurring south of a stalled frontal boundary across the Gulf coast states along 32N. Also, over the Gulf waters, a 1014 mb low is located near 29.5N87W with a surface trough extending W-SW to near 28N91W. A weak ridge dominates the remainder of the basin. Under this pattern, gentle to locally moderate winds and slight seas 3 ft or less prevail. For the forecast, weak will persist across the Gulf waters through early next week, supporting moderate or lighter winds and slight seas. Winds will pulse to fresh with moderate seas off western Yucatan during the evenings due to a diurnal surface trough moving west off the peninsula each night. A nearly- stationary front will meander near the northern Gulf waters during the next few days producing thunderstorms along and to the south of the front. Mariners can expect gusty winds and higher seas associated with the stronger thunderstorms. ...CARIBBEAN SEA... The Atlantic subtropical ridge extends across the central Atlantic along about 36N then SW to coastal Georgia along 31N. The pressure gradient south of this ridge supports fresh to strong easterly trade winds and rough seas to 9 ft in the south- central Caribbean, to around 30 kt across the Gulf of Venezuela and NE Colombia. Moderate to fresh easterly winds and moderate seas are found in the eastern Caribbean, Gulf of Honduras and Windward Passage. Elsewhere, moderate or weaker winds and slight to moderate seas prevail. Scattered showers and thunderstorms are occurring in the SW Caribbean ahead of a tropical wave. For the forecast, the remnants of Tropical Storm Dolly are now a strong tropical wave moving quickly westward, and will cross 55W Sat morning. This tropical wave will then approach the waters east of the Leeward Islands late Sat, bringing strong winds with gale-force wind gusts, rough seas, and accompanied by squalls and thunderstorms that will spread across the far NE Caribbean, the Virgin Islands, Puerto Rico and the adjacent waters Sat evening into early next week. Otherwise, the pressure gradient between high pressure north of the basin and lower pressure over South America will support strong trades and rough seas over the south- central Caribbean this weekend. These winds will diminish some early next week as the aforementioned tropical wave disrupts the pressure gradient, but will increase again by the middle of next week. ...ATLANTIC OCEAN... A Gale Warning is in affect in association the remnants of Dolly, now a tropical wave along 51W. Please, refer to the Special Features section for more details. Scattered showers, with embedded thunderstorms, dot the waters between Bermuda and the Bahamas, particularly N of 23N and W of 67W. Converging middle level winds and a diffluent pattern aloft are helping to induce this convective activity. A ridge dominates the remainder of the Atlantic forecast waters, anchored on a pair of surface highs, one 1030 mb high pressure located SW of the Azores near 37N32W, and a second 1027 mb high near 36N52W. The ridge supports moderate to locally fresh easterly winds and moderate seas across much of the SW North Atlantic S of 26N and W of 35W. Farther E, fresh to strong NE winds and moderate to rough seas prevail N of 18N and E of 24N to the coast of W Africa, including the Canary Islands. Moderate to locally fresh winds and moderate seas prevail elsewhere to 35W, under the influence of the ridge. For the forecast west of 55W, the strong tropical wave associated with the remnants of Tropical Storm Dolly will bring strong winds, rough seas, squalls and thunderstorms waters S of 23N as it moves across the southeastern zones E through NE of the Leeward Islands late Sat through Sun, and then reaches the Atlantic waters near the Virgin Islands and Puerto Rico early Sun through Sun night, and spreads toward Hispaniola Sun night through Mon. Elsewhere, the subtropical ridge will dominate the SW N Atlantic waters over the next several days supporting mainly moderate or weaker winds and moderate seas. Winds will pulse to locally strong off northern Hispaniola each night.