Atlantic Tropical Weather Discussion
891 AXNT20 KNHC 211711 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1815 UTC Mon Sep 21 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... An eastern Atlantic tropical wave has its axis near 30-31W, south of 19N, moving westward at around 10-15 kt. No significant convection is noted with this wave. The axis of a central Atlantic tropical wave is analyzed from 21N43W to 06N48W, moving westward at around 10 kt. Scattered moderate convection is active on the northern end of the tropical wave from 18N to 22N between 41W and 45W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends off the coast of Africa near 14N17W to 07N35W. The ITCZ extends from 07N35W to 04N52W. Scattered moderate convection is noted from 06N to 16N and east of 25W. Scattered showers are also noted along and within 100 nm of these features W of 25W. ...GULF OF AMERICA... A very weak pressure gradient prevails across the area generating light to gentle winds and slight seas across the Gulf. An upper low centered over northern Florida is interacting with a pair of surface troughs in the eastern Gulf to support scattered showers and isolated thunderstorms N of 23N and E of 90W. Another surface trough extending into the Gulf from NE Mexico is supporting scattered showers and isolated thunderstorms in the W Gulf as well. For the forecast, a very weak pressure gradient will force only gentle to moderate winds across the Gulf through Thu. A vigorous upper- level low will promote scattered showers and thunderstorms over the SE Gulf and the Straits of Florida for at least the next two days. Looking ahead, a cold front should dip into the NE Gulf Thu night and Fri with fresh NE to E winds to follow across the N Gulf. ...CARIBBEAN SEA... The eastern extension of the East Pacific monsoon trough extends across the far SW Caribbean, with a 1010 mb surface low analyzed near 12N81W. These features are interacting with an upper level trough over the Gulf of America and NW Caribbean to support numerous moderate to strong convection across the Caribbean between 75-85W, with scattered showers and isolated thunderstorms noted along the coasts of Honduras, Belize and the Yucatan Peninsula. Outside of convection, a weak pressure pattern is across the basin. Moderate to fresh winds and moderate seas prevail east of 80W. Light to gentle winds and slight to moderate seas prevail west of 80W. For the forecast, a weak pressure gradient between high pressure north of the area to the Colombian Low is forcing only moderate to fresh trades over the S central Caribbean for the next several days. A vigorous upper-level low is forcing scattered to numerous showers and thunderstorms over the W Caribbean for at least the next two days. ...ATLANTIC OCEAN... For awareness, Tropical Storm Fay is centered near 33.3N 32.0W at 21/1500 UTC or 370 nm SW of the Azores, moving S at 4 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Please visit hurricanes.gov for more info on Tropical Storm Fay. An upper trough reaches from the eastern Gulf into the northwest Caribbean. Divergent flow aloft on the east side of the upper trough is supporting clusters of showers and thunderstorms across a large area N of 20N and W of 67W. Farther eastward in the central Atlantic, an upper level low near 26N48W and surface trough extending from 32N41W to 22N55W are interacting with the central Atlantic tropical wave to support scattered moderate convection from 20N to 31N between 36W and 45W, as well as more scattered showers along and near the surface trough. Outside of convection, a very weak pressure gradient across much of the Atlantic supports gentle to moderate trades and 3-6 ft seas across much of the basin. For the forecast west of 55W, a very weak pressure gradient between the Bermuda- Azores High and lower pressure over the ITCZ is promoting only gentle to moderate trades across forecast waters through Thu. A vigorous upper-level low will continue to produce scattered showers and thunderstorms west of 65W for at least the next couple of days. Looking ahead, a cold front will emerge from the SE United States coast late Wed night and extend from 31N71W to the central Bahamas Fri morning. Fresh N winds and increasing seas will follow the front.