Atlantic Tropical Weather Discussion
271 AXNT20 KNHC 230440 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0615 UTC Wed Sep 23 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 0330 UTC. ...SPECIAL FEATURES... Heavy Rainfall in Central America, Jamaica, and Cuba: A middle to upper-level trough currently extends from the eastern Gulf of America across the Yucatan Peninsula and NW Caribbean, while relatively warm sea surface temperatures and abundant low level moisture are present. An elongated low level trough will develop across this area during the next several days, and aid in funneling enhanced tropical moisture across Central America and the western Caribbean, supporting periods of heavy rainfall tonight through Sat the 26th. There is still some uncertainty regarding the exact location of heaviest rainfall, but for now heavy rainfall looks likely across extreme southeastern Mexico near Chiapas, southern and central Guatemala, western Honduras, El Salvador, southern and eastern Belize, as well as across portions of Costa Rica and Panama. Currently, very heavy rainfall is ongoing from the NW coastal waters of Jamaica, westward across the Cayman Islands to 83W and then northward across east-central Cuba to Andros Island in the Bahamas. Scattered pockets of moderate convection are elsewhere across the Gulf of Honduras, and the remainder of the Bahamas. Heavy rainfall in these regions will create the possibility of life- threatening flash flooding and landslides. Please refer to local weather services as well as the International Desk at the Weather Prediction Center for more information. ...TROPICAL WAVES... An Atlantic tropical wave is analyzed along 40W, S of 15N, moving westward at 15 kt. Scattered moderate convection is about the monsoon trough in this area from 10N to 11.5N between 38W and 45W. An Atlantic tropical wave has its axis along 56W south of 16N, moving westward at 10 to 15 kt. Widely scattered showers and isolated thunderstorms are noted from 08.5N to 11.5N between 54W and 60W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis exits Africa along the Guinea coast near 10N14.5W and extends southwestward to 1009 mb low pressure near 09N16W to 10.5N23W to 09.5N43W, where it transitions to the ITCZ and continues to 08N50W and to 09N56W. Scattered to locally numerous moderate to strong convection is noted from 05.5N to 11.5N E of 25W to the coast of Africa. ...GULF OF AMERICA... A very weak pressure gradient remains across the Gulf basin as weakening high pressure across the SE U.S. extends a ridge across the northern Gulf. A broad and persistent middle to upper-level trough over the eastern Gulf is supporting very active thunderstorms over portions of the NW Caribbean and across eastern Cuba into the Bahamas, while convection across the Gulf has diminished in recent hours, with widely scattered moderate convection across the Straits of Florida and into the SW Florida waters across the Fort Meyers area. A weak surface trough lingers from central Florida into the the SW Gulf to the western Straits of Florida. The current surface pattern is generally producing light to gentle easterly winds and slight seas across the Gulf. Moderate E-NE winds and seas to 3 ft are occurring well offshore of southern Texas between 93W and 95W. For the forecast, the current weak pressure pattern across the Gulf will continue to generate gentle to moderate winds across the Gulf through Thu. The persistent middle to upper-level trough will support scattered showers and thunderstorms over the SE Gulf and the Straits of Florida for at least the next couple of days. A cold front is forecast to move into the NE Gulf Thu night and Fri. The front will shift southward accompanied by increasing winds and seas, before stalling over the SE Gulf this weekend. ...CARIBBEAN SEA... Please refer to the Special Features section above for information on impactful weather across the northwestern Caribbean. Outside of the active convection across the NW Caribbean, fair weather dominates most of the basin. Scattered showers accompany a low level trough moving across the Leeward Islands, while evening convection is diminishing across SW Hispaniola. At the surface, a weak pressure pattern is across the basin, as 1022 mb Atlantic high pressure is located E of Bermuda along 57W and extends a ridge into the SE Bahamas. Moderate trades prevail across most of the basin E of 76W, where seas are 3 to 5 ft, while fresh to strong winds are S of 14N to the coasts of NW Venezuela and extreme NE Colombia, where seas are 5 to 7 ft. Outside of convection, light to gentle winds and slight seas prevail across the remaining waters of the western Caribbean. For the forecast, a weak pressure gradient will continue across the basin to produce moderate to fresh trades over the S central Caribbean, and gentle to moderate winds elsewhere. A deep layered upper trough over NW portions will support scattered to numerous showers and thunderstorms over the W Caribbean for at least the next couple of days. ...ATLANTIC OCEAN... Of note: What was previously Tropical Depression Fay is now a post-tropical remnant low pressure of 1013 mb centered near 30.5N 36W, or about 630 nm southwest of the Azores. Winds of 20-30 kt continue within 180 nm across the N semicircle, where buoy observations suggest seas are 8 to 13 ft. Scattered moderate convection has increased in recent hours, and within 90 nm across the E semicircle of the low. Scattered showers and thunderstorms remain active across the NW Caribbean, across eastern Cuba and over much of the Bahamas and adjacent Atlantic waters S of 27.5N and W of 75W. This activity is occurring due to the combination of ample moisture across the area and unstable conditions created by the persistent and deep layered upper trough across the eastern Gulf of America and NW Caribbean. Another upper-level low is drifting westward near 26N51W. This feature is interacting with several surface troughs in the central Atlantic resulting in an area of scattered moderate convection from 22.5N to 28N between 41W and 53W. Another surface trough is moving westward across the Lesser Antilles, and producing scattered showers and a few thunderstorms across the Leeward Islands and adjacent Atlantic waters W of 59W. Outside of this convection, a rather weak pressure gradient continues across much of the Atlantic, with 1022 mb high pressure across the Atlantic E of Bermuda along 57W producing a modest ridge into the SE Bahamas, while a surface trough lingers from central Florida to near 31N76W. This pattern is sustaining mostly gentle to moderate trades S of 23N and variable light to gentle winds elsewhere W of 50W, except for moderate SE to S winds over the area N of 25N between 58W and 70W. Seas are 4 ft or less across this area except 5 to 8 ft N of 26N between 49W and 52W. Elsewhere, the Azores high is centered across the NE Atlantic along 20W and extends a ridge southwestward and drapes across the remnant low of Fay near 30.5N36W. The resultant pressure gradient is yielding moderate N to NE winds from the Canary Islands to the Cabo Verdes, with strong winds along the coast of Africa. Seas there are 3 to 6 ft. Moderate NE trades prevail S of 21N between the Cabo Verdes and 50W, where seas are4 to 6 ft. N of this area winds are light to gentle. However, long period N to NE swell has moved into the waters N of 25N and E of 52W, where seas are 6 to 8 ft. For the forecast west of 55W, a continued weak pressure gradient will support gentle to moderate trades across forecast waters through Wed night. An upper-level trough will support scattered showers and thunderstorms west of 65W for the next couple of days. A cold front will move off the SE United States coast late Wed night. The front will shift eastward, reaching from near Bermuda to the straits of Florida Sat night before starting to weaken. Fresh to strong winds and increasing seas in large NE swell will follow the front on Thu and Fri.