000 AXNT20 KNHC 211033 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1215 UTC Sun Sep 21 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 0600 UTC surface analysis and satellite imagery through 1030 UTC. ...SPECIAL FEATURES... Tropical Storm Gabrielle is centered near 27.2N 60.0W at 21/0900 UTC or 400 nm SE of Bermuda, moving NNW at 8 kt. Estimated minimum central pressure is 995 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Seas 12 ft or greater are noted 25N-29N between 57W-62W. Scattered to numerous moderate to strong convection is from 23N-30N between 54W-62W. On the forecast track, the center of Gabrielle is expected to pass east of Bermuda on Monday. Swells generated by Gabrielle will continue to affect Bermuda during the next few days. These swells are expected to reach the east coast of the United States from North Carolina northward, as well as Atlantic Canada, beginning later today and continuing through early this week. These swells are likely to cause life- threatening surf and rip current conditions. Please consult products from your local weather office. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Gabrielle NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis near 32W, south of 21N, moving westward at 10 kt. A 1011 mb low is along the wave axis near 13N33W. Scattered moderate convection is noted from S of 15N between 30W-36W. A central Atlantic tropical wave has its axis near 47W, south of 21N, moving westward at 10 kt. Scattered moderate convection is over the northern half of the wave. A western Caribbean tropical wave is along 81W, from 21N southward from the Cayman Islands to Panama. Scattered showers are noted along the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic off the coast of Mauritania near 19N16W and continues to 10N40W. The ITCZ extends from 10N40W to 12N46W, then resumes W of a tropical wave near 12N48W to 09N60W. GULF OF AMERICA... Scattered moderate to isolated strong thunderstorms are active near a trough along the west coast of the Yucatan Peninsula. Elsewhere, weak 1019 high pressure centered along the north- central Gulf coast off Mississippi provides for gentle to locally moderate E winds and moderate seas across the basin. For the forecast, surface ridging will control the general weather pattern through the weekend before shifting NE and weakening by midweek. With Tropical Cyclone Gabrielle over the Atlantic lifting northward through Mon night, Atlantic ridging will build westward along the northern Gulf early next week. Mainly gentle to moderate winds and slight seas will prevail across the basin. CARIBBEAN SEA... Refer to the section above for details on the tropical wave moving across the basin. Little thunderstorm activity is currently ongoing across the basin, outside of the thunderstorms already described in the Tropical Wave section near Jamaica and Cuba. The subtropical ridge north of the area is disrupted by the presence of Gabrielle in the Atlantic, and this pattern is supporting only gentle to moderate trade winds across the eastern and central Caribbean, east of the tropical wave in the western Caribbean. Light breezes are noted elsewhere west of the wave across mainly the northwest Caribbean. The exception may be moderate E winds along the coast of eastern Honduras. Slight seas prevail across the basin. For the forecast, gentle to moderate trades along with moderate seas are expected today, increasing slightly thereafter basinwide as the pressure gradient tightens in the wake of Tropical Cyclone Gabrielle moving through the central Atlantic. Fresh to strong winds may pulse in the S-central portion of the basin Mon night. ATLANTIC OCEAN... Refer to the sections above for details on Tropical Storm Gabrielle, and on the tropical waves across the eastern Atlantic. A few showers and thunderstorms are active over the central Bahamas, along a surface trough that persists from 31N75W across the northern Bahamas. Moderate to fresh NE winds are west of the trough to the coast of Florida, with moderate seas. Farther east, a cold front is approaching the Canary Islands from the north. Elsewhere, outside of the main impact area of T.S. Gabrielle described above in the Special Features section, ridging north of the area is supporting moderate to fresh trade winds across the basin with moderate seas. For the forecast west of 55W, Tropical Storm Gabrielle will strengthen to a hurricane near 28.3N 60.9W this afternoon, move to 29.9N 61.6W Mon morning, 31.5N 61.3W Mon afternoon, 33.1N 59.7W Tue morning, 34.5N 56.8W Tue afternoon, and 35.4N 52.9W Wed morning. Gabrielle will weaken to a tropical storm near 36.9N 41.7W by early Thu. A surface trough will persist off the SE U.S. coast to the northern Bahamas through at least the remainder of the weekend enhancing convection in the vicinity. Otherwise, in the wake of Gabrielle, central Atlantic high pressure will build westward providing for light to gentle winds over the central and western portions of the area, and for gentle to moderate winds over the eastern portion into midweek. Seas associated with Gabrielle will gradually subside by midweek. $$ ERA