Atlantic Tropical Weather Discussion
810 AXNT20 KNHC 130410 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0615 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 0000 UTC surface analysis and satellite imagery through 0330 UTC. ...SPECIAL FEATURES... Caribbean Gale Warning: A tight pressure gradient between the western Atlantic subtropical ridge centered along 71W and lower pressures associated with the Colombian Low supports fresh to strong winds across a large portion of the central Caribbean tonight. Winds have increased to gale-force off the coast of Colombia S of 12.5N, where seas are 11-12 ft. Winds there will diminish below gale-force by sunrise. This pattern is expected to continue for the next several days, and maintain these rough marine conditions. A Gale Warning has been issued for the waters off of Colombia through 0900 UTC. 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... An Atlantic tropical wave has been added to the 0000 UTC surface analysis along 38W/39W, south of 16N, moving westward near 20 kt. Latest satellite imagery, precipitable water, and scatterometer data depict this wave. Scattered moderate isolated strong convection is noted from 06N to 15N between 36W and 41.5W. The axis of a tropical wave is near 45W, from 08N to 18N, moving westward near 20 kt. Widely scattered moderate convection is seen near the wave axis between 42W and 46W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Guenia-Bissau near 12N16.5W, and continues to 08N26W to 11N39W to 10.5N44W. The ITCZ extends from 10N46W to the coast of NE Venezuela near 10.5N63W. Beyond weather described with tropical waves, scattered moderate isolated strong convection is noted from 05.5N to 10N between 14W and 33W, and from 09N and 12.5N between 46W and 55W. ...GULF OF AMERICA... Convection has diminished significantly across the northern Gulf early tonight. Scattered moderate isolated strong convection continues within 75 nm of the W coast of Florida from Cedar Key to the Florida Keys. and then across the Yucatan Channel. A strong convective cluster is shifting off the western coast of the Yucatan Channel and into the eastern Bay of Campeche. Weak high pressure persists over the NE Gulf and is promoting generally light to moderate anticyclonic flow across the basin, with seas of 3 ft or less. Moderate to fresh NE winds prevail along the NW and W coasts of the Yucatan, while moderate SE winds prevail across the coastal waters of NE Mexico and southern Texas, where seas are 3 to 4 ft. For the forecast, weak high pressure will maintain relatively tranquil conditions across Gulf waters into the start of next week. 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 NE winds followed by showers and thunderstorms. Starting later 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 over the NE basin Wed and Thu. Conditions will improve late next week. ...CARIBBEAN SEA... As previously mentioned, the pressure gradient between surface ridging over the western Atlantic and the Colombian low supports fresh to strong easterly trade winds and rough seas over much of the central Caribbean, S of 18N between 64W and 81W. Fresh to strong winds and seas to 6 ft are found across the Gulf of Honduras S of 17N. Moderate to fresh easterly winds and moderate seas are found in the eastern Caribbean E of 64W, while moderate or weaker winds and slight seas are prevalent elsewhere. An upper- level trough over the NW Caribbean is helping to sustain convection over Haiti, and the NW Caribbean between Jamaica and central Cuba. Scattered showers and thunderstorms are noted over the western Basin from the Yucatan Channel to the Gulf of Honduras, and across the coastal waters of Panama, Costa Rican and Nicaragua. For the forecast, the pressure gradient between the western Atlantic subtropical ridge and lower pressures associated with the Colombian Low has increased in the past 24 hours, as the most recent tropical wave has exited the eastern Caribbean and moved into the eastern Pacific. This pattern 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. Winds will pulse to gale force tonight offshore Colombia, then diminish by sunrise. Strong winds are expected tonight and Sun night in the Gulf of Honduras. Meanwhile, moderate to fresh easterly breezes are expected over the next few days in the eastern Caribbean. ...ATLANTIC OCEAN... A deep layered upper-level trough extends from the central Atlantic near 33N41W southwestward to N of Hispaniola to near Jamaica, and is supporting several areas of significant convection across the basin tonight. A band of showers and thunderstorms covers the area from 23N to 26.5N between 61W and 72W. A low to middle level trough along about 42W from 20N to 28N is favorably interacting with this upper trough to produce scattered showers and thunderstorms from 22N to 30N between 38W and 43W. At the surface 1020 mb high pressure is centered near 31N71W and is producing anticyclonic flow N of 25N and W of 65W. A lingering surface trough from the Straits of Florida to near 30N77W is helping to focus scattered thunderstorms that have shifted southeastward off of SE Florida and into the coastal waters between the NW Bahamas to across the Florida Keys in the past few hours. A pair of weak surface troughs N of 20N between 50W and 65W aid in separating the western Atlantic ridge from stronger high pressure across the NE and E Atlantic. 1026 mb high pressure centered NE of the Azores extends a ridge southwestward to 30N40W. The pressure gradient between this ridge and lower pressure across NW Africa is producing fresh to locally strong N to NE winds from offshore of Europe along 35N through the Canary Islands to 25N and E of 25W. Seas are 6 to 9 ft across this area. Of note, a gale- force easterly gap wind event is occurring in the Straits of Gibraltar. Elsewhere across the tropical Atlantic moderate to locally fresh trade winds prevail S of 22N between 30W and the Lesser Antilles. Seas are 4 to 7 ft across this zone. To the north of these trades, winds are moderate or less with seas 4 ft or less. For the forecast west of 55W, the western Atlantic subtropical ridge will continue to dominate through Mon night, producing mainly tranquil marine conditions. However, trades north of Hispaniola into the Windward Passage will pulse fresh to locally strong into Monday. On Tue, strong high pressure building SE 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 night through Wed night.