Atlantic Tropical Weather Discussion
352 AXNT20 KNHC 120450 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0615 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 0000 UTC surface analysis and satellite imagery through 0430 UTC. ...TROPICAL WAVES... The axis of a tropical wave is near 37W-38W, south of 24N, moving westward at 15 to 20 kt. The portions of the wave N of 18N is shifting northwestward, forced by middle level southeasterly flow behind it. Scattered moderate convection is from 21N to 25N near this portion of the wave. Scattered moderate convection is also about the southern portion of the wave, from 07.5N to 12N between 34W and 44W. A tropical wave previously analyzed over the central Caribbean along 76W is no longer clearly evident, and has been dropped from the 00Z analysis. However, a wind surge is suggested across that area, and is approaching the next tropical wave across the western Caribbean. A second tropical wave is over the NW Caribbean near 85W-86W, south of 20N, moving westward at 15 to 20 kt. Scattered to locally numerous squalls and thunderstorms are across the NW basin and Gulf of Honduras, from 15.5N to 20.5N between 78W and 86w. Scattered moderate convection is noted about the eastern Pacific monsoon trough and Central America and into the eastern Pacific waters, affecting parts of Honduras, Nicaragua. Costa Rica and Panama. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Senegal near 14N17W, and continues to 09N21W to 13N32W to 11N39W. The ITCZ extends from 10.5N43W to the coast of Venezuela near 08.5N61W. Aside from convection associated with the tropical wave, numerous moderate to strong convection is noted from 09N to 12N between 47W and 61W. ...GULF OF AMERICA... Evening convection across the basin has diminished significantly in recent hours, with scattered moderate convection continuing across the Florida Big Bend N of 27N. A very weak pressure pattern prevails across the Gulf basin, with 1017 mb high pressure over north-central Florida yielding a generally light to gentle anticyclonic wind flow. Moderate E to NE winds prevail across NW and W coastal waters of the Yucatan Peninsula, ahead of the typical surface trough over the peninsula, while moderate to locally fresh winds are near the coast of northeastern Mexico and south Texas. Seas are 3 ft or less basin-wide, except 3-5 ft within 120 nm of the coasts of northeastern Mexico and south Texas. For the forecast, high pressure will prevail across the NE Gulf waters during the next several days. Winds will pulse to fresh speeds each night off the W Yucatan peninsula due to a diurnal trough moving toward the SW Gulf. By the middle of next week, a building ridge over the eastern United States and a frontal trough will combine to increase winds to fresh speeds over the Gulf waters N of 23N. ...CARIBBEAN SEA... Weak high pressure is centered N of the basin, between the Bahamas and Bermuda. The pressure gradient between the associated ridge and the Colombian low supports fresh to strong trade winds and rough seas over much of the central Caribbean S of 18N, as noted in recent satellite scatterometer data. Seas are 8 to 11 ft S of 17N over the south- central Caribbean. Elsewhere moderate to locally fresh trade winds and moderate seas are evident, with the exception of light to gentle winds over the NW Caribbean. An upper-level trough over the NW Caribbean is enhancing convective activity associated with the tropical wave across the western basin. Fair weather prevails across the area E of 78W. For the forecast, the pressure gradient between the subtropical ridge north of the area and lower pressures associated with the Colombian Low will continue to force strong to locally near-gale easterly trade winds and rough to locally very rough seas over the central Caribbean for the next several days. Meanwhile, moderate to fresh easterly breezes are expected over the next few days in the eastern Caribbean. Winds will pulse to strong speeds in the Gulf of Honduras late Sat through Mon morning. Elsewhere, moderate or weaker winds and slight to moderate seas will be prevalent. ...ATLANTIC OCEAN... A frontal trough extends from 31N44.5W to 25N53W to 31N64W. Upper level low pressure located E of the southeast Bahamas is supportingscattered showers and thunderstorms S of this trough, from 24.5N to 28.5N between 55W and 73W. The remainder of the forecast waters are dominated by high pressure, with a 1026 mb high center of 1023 mb located offshore of NW Spain, and 1018 mb high near 28N69W. The pressure gradient between the eastern Atlantic high pressure and lower pressures over NW Africa is promoting moderate to fresh N to NE winds N of 16N and E of 22W, including the Canary Islands. Moderate to fresh trade winds are observed E of the Lesser Antilles to about 50W, where seas are 5 to 7 ft, and also along the N coast of Hispaniola. Moderate or weaker winds prevail elsewhere. Seas are, in general, moderate across the Atlantic forecast waters. For the forecast west of 55W, the subtropical ridge will dominate the SW N Atlantic waters over the next several days. Trades north of Hispaniola into the Windward Passage will be fresh to locally strong through early next week. Looking ahead, a building ridge over the eastern United States and a frontal trough will combine to increase winds to fresh speeds and build seas to locally rough north of the Bahamas and W of 70W starting early next week and continuing through Wed night. Elsewhere, moderate or weaker winds and slight to moderate seas will prevail.