411 AXNT20 KNHC 041510 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1815 UTC Thu Sep 4 2025 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 1500 UTC. ...SPECIAL FEATURES... Eastern Tropical Atlantic: An eastern Atlantic tropical wave is along 36W, south of 19N, moving westward at 10-15 kt. Scattered moderate convection is observed from 12N to 14N and between 30W and 35W. Environmental conditions are conducive for development of this system during the next several days, and a tropical depression is likely to form late this week or this weekend over the eastern or central tropical Atlantic. There is a medium chance of formation within the next 2 days, and a high chance within the next 7 days. Refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...TROPICAL WAVES... Refer to the Special Features section above on an eastern Atlantic tropical wave. An eastern Caribbean tropical wave is along 62W south of 21N, and moving westward at 10-15 kt. Scattered moderate convection is active from 12N to 14N between 62W and 64W. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic through the coast of Mauritania near 17N16W and continues southwestward to 1011 mb low pressure near 12N33W, then westward to near 09N45W. An ITCZ extends from 09N45W to 09N60W. Scattered moderate convection is present from 06N to 09N between 15W and 25W, and 08N to 11N between 42W and 47W. ...GULF OF AMERICA... A frontal trough extends from the Florida Keys to 1009 mb low pressure in the east-central Gulf near 27N86W to 24N93W. Scattered showers and thunderstorms cover much of the eastern Gulf to the south of the trough. Moderate E winds and 3 to 4 ft seas are evident across the southeast Gulf, south of the low pressure. Light to gentle to breezes and slight seas are noted elsewhere. For the forecast, the frontal trough will persist over the east-central Gulf through Sat and continue to generate scattered to numerous showers and isolated thunderstorms, mainly across the eastern part of the basin. A cold front is forecast to enter the northern Gulf waters on Sun, becoming stationary early next week. Winds and seas will increase in the NE Gulf behind the front, especially by the middle of next week. Elsewhere, a weak pressure gradient in place will maintain gentle to moderate winds with slight to locally moderate seas through the forecast period. ...CARIBBEAN SEA... In addition to the scattered showers and thunderstorms ahead of the tropical wave in the southeast Caribbean west of the Windward Islands, scattered convection is also ongoing over the far southwest Caribbean off Panama and Costa Rica associated with convergent low level trade wind flow north of the monsoon trough. Farther north, a small cluster of thunderstorms is active off southeast Cuba in the Gulf of Guacanayabo related divergent flow aloft and local morning land breeze convergence. Moderate trade convergence and 3 to 5 ft seas cover much of the eastern and central Caribbean, except for fresh trade winds and 5 to 7 ft seas off Colombia. Light to gentle breezes and 1 to 3 ft seas are observed over the northwest Caribbean. For the forecast, the subtropical ridge will continue to force moderate to fresh easterly trade winds along with moderate seas across much of the central Caribbean through early Sun. Fresh to locally strong winds are expected to pulse off Colombia and the Gulf of Venezuela at night through Fri night. In addition, moderate to locally fresh E winds and slight to moderate seas will prevail in the Gulf of Honduras through Sat night. A tropical wave will move into the eastern Caribbean today, continue westward into the central Caribbean this weekend and across the western Caribbean early next week. Convection associated with this tropical wave is currently limited. ...ATLANTIC OCEAN... Please read the Special Features section about the potential development of a tropical depression in the eastern and central Atlantic. A stationary front extends from 1009 mb low pressure over the north-central Atlantic near 46N37W, to off the eastern seaboard of the United States, then across the northern Bahamas and South Florida and into the far southeast Gulf of America. Scattered showers and thunderstorms are active with 90 nm east of the front south of 31N. Farther east, a cold-core mid to upper level low is centered near 24N60W, supporting scattered showers and thunderstorms within a 240 nm radius. An associated surface trough extends from 27N55W to 24N59W. As discussed in the Special Features section above, a 1011 mb low pressure is analyzed near 12N133W, close to where a tropical wave is interacting with the monsoon trough. A recent scatterometer satellite pass indicated fresh winds within 90 nm of this low pressure center. Broad ridging dominates the remainder of the subtropical Atlantic north of 25N, anchored by 1027 mb high pressure centered near 34N40W. This pattern is supporting generally moderate winds and seas elsewhere across the basin, except for fresh to strong NE winds and locally rough seas off northwest Africa. For the forecast west of 55W, the frontal boundary will persist east of Florida through the weekend, but will drift westward as the Atlantic high pressure moves also westward over the next few days. Moderate to fresh S winds are expected ahead of the boundary through late today. Scattered to numerous showers and thunderstorms E of the front are affecting the NW Bahamas, South Florida, the Straits of Florida and Cuba. Unsettled weather conditions will continue ahead of the front over the next few days. Stronger winds and higher seas are likely near thunderstorms. Elsewhere, the Atlantic ridge will continue to dominate the weather pattern across the forecast waters, supporting gentle to moderate winds and mostly moderate seas. $$ Christensen