Atlantic Tropical Weather Discussion
625 AXNT20 KNHC 130929 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1215 UTC Sun Sep 13 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 0600 UTC surface analysis and satellite imagery through 0925 UTC. ...TROPICAL WAVES... A central Atlantic tropical wave is along 42W, south of 16N, moving westward at 20 kt. Scattered moderate to isolated strong convection is found within 120 nm on both sides of the trough axis. Another central Atlantic tropical wave is along 46W, south of 17N, moving westward at 15-20 kt. A few showers are found near this wave. ...MONSOON TROUGH/ITCZ... The monsoon trough reaches the Atlantic through the coast of Guinea near 13N16W and continues WSW to 09N27W and then to 11N44W. The ITCZ extends from 10N47W to the coast of NE Venezuela near 10.5N63W. Scattered moderate to isolated strong convection is observed within 120 nm on both sides of the monsoon trough and ITCZ. ...GULF OF AMERICA... A 1017 mb high pressure system over central Florida and lower pressures over Mexico supports moderate to locally fresh easterly winds and moderate seas in the south-central Gulf waters. Moderate E-SE winds and seas of 2-4 ft are found in the western Gulf. Elsewhere, under the broad ridge, light to gentle winds and slight seas prevail. For the forecast, weak high pressure over central Florida will continue to support relatively tranquil conditions to the Gulf waters into Tue. The exception will be the Bay of Campeche, where a diurnal trough will move westward offshore the Yucatan Peninsula each evening, bringing nightly pulses of fresh to locally strong NE winds. Starting late Tue, stronger high pressure building southward from the eastern United States will lead to increasing NE to E winds over the basin, with speeds reaching fresh to strong force and rough seas over the northern Gulf Wed and Thu. Conditions will improve late this week. ...CARIBBEAN SEA... The tight pressure gradient between the subtropical ridge north of the islands and lower pressures in Colombia sustain strong to near gale-force NE-E winds over much of the central Caribbean. Rough to very rough seas are occurring in these waters. Fresh to strong NE-E winds and seas of 4-8 ft are found in the Windward Passage and Gulf of Honduras. Moderate to fresh easterly winds and moderate seas are evident in the eastern Caribbean. Elsewhere, moderate or weaker winds and slight to moderate seas prevail. An upper- level trough over the north-central Caribbean is helping to induce a few showers and thunderstorms over the eastern Caribbean. Similar convection is found in the SW Caribbean. For the forecast, the aforementioned tight pressure gradient will continue to support strong to near-gale easterly trade winds and rough to locally very rough seas over the central Caribbean for the next several days. Gale- force winds off Colombia will diminish below gale this morning. Strong winds are expected this morning and tonight in the Gulf of Honduras. Meanwhile, moderate to fresh easterly breezes are expected over the next few days in the eastern Caribbean. ...ATLANTIC OCEAN... Scattered showers and isolated thunderstorms are occurring between Bermuda and the Greater Antilles, especially north of 22N and between 55W and 72W. A broad subtropical ridge dominates the SW North Atlantic, supporting moderate or weaker winds and seas of 3-5 ft. However, a tighter pressure gradient north of Hispaniola and in the Windward Passage allow for fresh to locally strong easterly winds and moderate seas. The interaction between a surface trough along 44W and an upper level low near 26N50W continue to support scattered showers and isolated thunderstorms east of the trough axis to 38W and north of 22N. An extensive subtropical ridge over the central Atlantic sustains moderate to locally fresh easterly winds and moderate seas south of 20N and west of 45W. East of 45W, moderate to fresh NE-E winds and moderate seas are prevalent. In the remainder of the basin, moderate or weaker winds and moderate seas prevail. For the forecast west of 55W, a broad subtropical ridge will persist over the basin through Mon night, bringing mainly tranquil marine conditions. However, trades north of Hispaniola into the Windward Passage will be fresh to locally strong into Mon. On Tue, strong high pressure building southward through the eastern United States will bring a cold front into the NW waters, increasing NE winds to fresh to strong and causing seas to build to rough N of the Bahamas and W of 70W Tue through Wed night. Conditions will improve late this week.