Atlantic Tropical Weather Discussion
693 AXNT20 KNHC 151543 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1815 UTC Tue Sep 15 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 1543 UTC. ...TROPICAL WAVES... A well defined tropical wave is along 56W, south of 21N, moving westward at 10-15 kt. Moderate to fresh E winds along with seas 4 to 6 ft are found in the vicinity of the wave. Scattered moderate to isolated strong convection is observed from 11N to 21N and between 51W and 59W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 13N17W and continues to 07N45W. The ITCZ extends from 07N45W to 10N54W. Scattered moderate to isolated strong convection is noted from 05N to 20N and east of 26W. ...GULF OF AMERICA... A few showers and isolated thunderstorms are occurring in the eastern Gulf waters and off Veracruz. A weak high pressure over the N Gulf supports moderate E to SE winds and 3 to 5 ft seas in the Bay of Campeche. Elsewhere, light to gentle winds and slight seas prevail. For the forecast, a strong high pressure over the eastern United States will build southward behind a weakening cold front that will spread across the eastern Gulf waters. The tighter pressure gradient will support fresh to locally strong NE-E winds and rough seas starting in the NE Gulf tonight and spreading over the northern Gulf waters through Thu night. Elsewhere, a diurnal trough will move westward offshore the Yucatan Peninsula each evening through Thu night, bringing nightly pulses of fresh to locally strong NE winds. Conditions will improve across the basin Fri, allowing for moderate or weaker winds and slight to moderate seas during the weekend. ...CARIBBEAN SEA... The interaction between an large upper-level low pressure system over the north-central Caribbean and tropical moisture support scattered showers and isolated thunderstorms south of Puerto Rico. This environment is also generating a few showers in the eastern Caribbean, bringing some rain to Puerto Rico and the Virgin Islands. High pressure north of the area sustains fresh to strong easterly trade winds and moderate to rough seas across much of the central Caribbean. Moderate to locally fresh NE-E winds and moderate seas are occurring in the eastern Caribbean, Windward Passage and lee of Cuba. Elsewhere, moderate or weaker winds and moderate seas prevail. For the forecast, tight pressure gradient between the subtropical ridge located north of the islands and lower pressures in Colombia will support fresh to locally near gale-force easterly trade winds and moderate to rough seas across much of the central Caribbean, with moderate to fresh trades elsewhere from 11N to 18N. These conditions will persist through the workweek. Elsewhere, moderate or lighter winds and slight to moderate seas are expected, except moderate to fresh mainly in the evenings near the Windward Passage and Lee of Cuba through midweek. Winds may diminish across the basin by the end of the week into the upcoming weekend as the pressures gradient relaxes, with seas also slightly subsiding. ...ATLANTIC OCEAN... A pre-frontal trough is noted ahead of an approaching cold front over the NW waters producing scattered showers and isolated thunderstorms north of 27.5N and between 68W and 76W. Meanwhile, a large upper-level low over and east of the SE Bahamas is supporting scattered showers south of 26N and between 61W and 72W. High pressure dominates the rest of the SW North Atlantic, sustaining moderate or weaker winds and slight to moderate. Another upper-level low over the central Atlantic interacts with a surface trough analyzed along 51.5W and north of 26N, producing numerous showers and isolated thunderstorms north of 26N and between 46W and 54W. Environmental conditions are forecast to become more conducive for development in a few days, and a tropical depression could form late this week as the system moves slowly west-northwestward over the subtropical Atlantic. The system has a medium chance of formation over the next 7 days. A strong subtropical ridge centered north of the Azores extends southward into the central and eastern Atlantic, supporting moderate to fresh easterly winds and moderate seas between 25W and 53.5W. Moderate or weaker winds and moderate seas are prevalent elsewhere. For the forecast west of 55W, a cold front is approaching the waters off NE Florida and then will become stationary from Bermuda to the NW Bahamas into Wed. A tight pressure gradient between the building ridge over the eastern United States and the front will result in fresh to locally strong NE winds and seas to build to rough N of the Bahamas and W of 70W through early Thu. Conditions will improve later Thu into Fri. During the middle to later portion of the week, a trough of low pressure is forecast to move west- northwestward into the NE portion of the waters, bringing thunderstorms while also weakening the high and pressure gradient.