Atlantic Tropical Weather Discussion
081 AXNT20 KNHC 121706 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1815 UTC Sat Sep 12 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 41W from 06N to 20N, moving westward at around 20 kt. Scattered showers are seen near the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Senegal near 13N17W, and continues to 10N24W to 13N35W to 10N44W. The ITCZ extends from 10N44W to the coast of Venezuela near 10N61W. Numerous moderate convection is noted from 08N to 14N between 44W and 63W. The eastern extension of the East Pacific monsoon trough extends across the far SW Caribbean. Scattered moderate and isolated strong convection are seen along and near the coasts of Nicaragua, Costa Rica, and Panama. ...GULF OF AMERICA... An upper level shortwave trough over the SE US and convergent surface winds over the eastern Gulf are supporting widely scattered moderate convection across a large region N of 24N and E of 95W. Elsewhere, the pressure gradient between higher pressure inland over Mexico and a surface trough in the Bay of Campeche supports moderate to locally fresh SE to S winds and seas of 3-5 ft across the Bay of Campeche and the far west Gulf. Gentle to moderate or weaker winds and seas of 1-3 ft prevail elsewhere. For the forecast, high pressure centered over the NE Gulf will dominate into the start of next week. Winds will pulse to fresh speeds each night off the W Yucatan peninsula due to a diurnal trough moving toward the SW Gulf. By Tue night, a building ridge over the eastern United States and a frontal trough will combine to increase winds to fresh to locally strong speeds and build seas over the Gulf waters N of 23N into late next week. ...CARIBBEAN SEA... The pressure gradient between surface ridging over the western N Atlantic and the Colombian low supports fresh to near gale-force easterly trade winds and rough seas over much of the central Caribbean S of 18N. Moderate to fresh easterly winds and moderate seas are found in the eastern Caribbean, while moderate or weaker winds and slight seas are prevalent elsewhere. An upper-level trough over the NW Caribbean is producing scattered showers and isolated thunderstorms. All other convection is described in the monsoon trough/ITCZ section above. Fair weather prevails across most of the Caribbean E of 77W. For the forecast, a tight pressure gradient between a subtropical ridge north of the islands and lower pressures associated with the Colombian Low will continue to support strong to locally near- gale easterly trade winds and rough to locally very rough seas over the central Caribbean for the next several days. Gusts to gale force are likely tonight off Colombia. Winds will pulse to strong speeds in the Gulf of Honduras this evening through Mon morning. Meanwhile, moderate to fresh easterly breezes are expected over the next few days in the eastern Caribbean. ...ATLANTIC OCEAN... An upper-level trough in the SW N Atlantic and surface trough paralleling the SE US coast are producing scattered moderate convection N of 23N and W of 72W. To the east, A frontal remnant trough extends from 31N44W to 26N55W to just south of Bermuda. A 1017 mb low is analyzed SE of Bermuda. Interactions between these features and the upper-level trough are supporting more scattered moderate convection from 24N to 30N between 56W and 67W, while scattered showers and isolated thunderstorms are occurring along the trough axis from 52W northeastward. Finally, a surface trough N of the tropical wave near 41W is also supporting isolated moderate convection along the trough axis. Outside of convection, surface ridging dominates much of the tropical Atlantic. Moderate to fresh NE to E winds and moderate seas dominate much of the basin E of 34W, as well as S of 20N and W of 40W. Gentle to moderate or weaker trades and 3-5 ft seas prevail elsewhere. For the forecast west of 55W, scattered thunderstorms between Bermuda and the Bahamas in association with an upper-level trough should diminish tonight. At the surface, the subtropical ridge will continue to dominate for the next several days. Trades north of Hispaniola into the Windward Passage will be fresh to locally strong into early next week. Looking ahead, a building ridge over the eastern United States and a frontal trough will combine to increase winds to fresh to locally strong speeds and build seas to rough north of the Bahamas and W of 70W starting Tue and continuing into Thu. Elsewhere, moderate or weaker winds and slight to moderate seas will prevail.