399 AXNT20 KNHC 110455 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0615 UTC Thu Sep 11 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 0000 UTC surface analysis and satellite imagery through 0425 UTC. ...TROPICAL WAVES... An eastern Atlantic tropical wave is along 33W, south of 18N, moving westward at 10 kt. Scattered moderate convection is observed from 14N to 17N and between 25W and 36W. A central Atlantic tropical wave is along 55W, south of 17N, moving westward at 10 kt. Scattered moderate convection is present from 11N to 15N and between 53W and 58W. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic through the coast of Mauritania near 19N16W and then continues southwestward to 13N35W and then to 12N53W. The ITCZ extends from 12N56W to 11N61W. Scattered moderate convection is present from 04N to 18N and east of 22W. Similar convection is noted from 05N to 14N and between 37W and 50W. ...GULF OF AMERICA... A stationary front continues draped across the central Gulf, extending from Fort Myers, Florida to south Texas. Scattered moderate convection is noted within 200 nm of the frontal boundary. Scattered showers and isolated thunderstorms are also seen in the Bay of Campeche. Gusty winds and higher seas are likely occurring near the strongest storms. The pressure gradient between the ridge over the central and eastern United States and lower pressures associated with the front support moderate to locally fresh easterly winds and slight to moderate seas north of 26N. Similar winds and seas are also evident off northern and western Yucatan. Elsewhere, light to gentle winds and slight seas are prevalent. For the forecast, the aforementioned front will gradually evolve into a cold front and move southward across the Gulf waters, likely reaching the south part of the basin by Sat. Showers and thunderstorms will continue along and ahead of the front through the week. Moderate to locally fresh NE to E winds and moderate seas are expected N of the front while mainly gentle winds and slight seas will prevail S of the front. ...CARIBBEAN SEA... An upper level low is moving westward across the western Caribbean, promoting the development of scattered showers and isolated thunderstorms across the region. A few showers are also seen near and south of the eastern Dominican Republic. At the surface, broad ridging positioned north of the islands and lower pressures over northern South America continue to force fresh to strong easterly trade winds across much of the central Caribbean. This was confirmed by a recent scatterometer satellite pass. Moderate to locally rough seas are occurring in these waters. The strongest winds and highest seas are found off northern Colombia and the Gulf of Venezuela. Moderate to locally fresh easterly winds and seas of 3-5 ft are noted in the eastern and NW Caribbean, especially south of 20N. Elsewhere, light to gentle winds and slight seas prevail. For the forecast, the pressure gradient between the Atlantic ridge and the Colombian low will lead to fresh to locally strong winds in the south central Caribbean into Friday, along with moderate to locally rough seas. Elsewhere, mainly moderate winds with slight to moderate seas are expected. ...ATLANTIC OCEAN... A stationary front, extending from 31N75W to Port Saint Lucie, Florida, continues to bring scattered showers and isolated thunderstorms to the SW North Atlantic, Bahamas and central and south Florida. Moderate northerly winds and moderate seas are present behind the frontal boundary. Farther east, a surface trough is along 66W, producing numerous showers and isolated thunderstorms from 21N to 27N and between 61W and 70W. Mariners navigating these waters can expect gusty winds near gale-force and higher seas. The remainder of the SW North Atlantic, west of 60W, is under the influence of a weak pressure gradient that result in moderate or weaker winds and moderate seas. In the north-central tropical Atlantic, a surface trough is along 51W and north of 24N. The interaction of this feature with an upper level low support scattered showers north of 23N and between 45W and 57W. The rest of the eastern and central tropical Atlantic is dominated by a 1031 mb high pressure system west of the Azores. The pressure gradient between the ridge and the monsoon trough sustain moderate to fresh easterly winds and seas of 6-9 ft north of 17N and between 20W and 50W. Similar winds and moderate seas are occurring south of 20N and west of 50W. In the far eastern Atlantic, east of 20N and north of 18N, fresh to strong N-NE winds and rough seas are evident. The strongest winds and seas peaking near 11 ft are found off Morocco. Elsewhere, moderate or weaker winds and moderate seas are prevalent. For the forecast west of 55W, the aforementioned front will transition to a cold front Thu and move SE, likely reaching the NW Bahamas and South Florida by Friday, before stalling again, and dissipating this upcoming weekend. The front will continue to bring showers and thunderstorms to waters near Florida and the northwest Bahamas through the week. Moderate to fresh N to NE winds and moderate to rough seas are expected N of the front through Sat. Ahead of the front, the Atlantic ridge will continue to dominate the weather pattern across the forecast region this week, producing a gentle to moderate anticyclonic flow and mostly moderate seas. $$ Delgado