000 AXNT20 KNHC 181653 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1815 UTC Thu Sep 18 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 1600 UTC. ...SPECIAL FEATURES... Tropical Storm Gabrielle is centered near 20.3N 51.7W at 18/1500 UTC or 660 NM ENE of the Northern Leeward Islands, moving WNW at 13 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Seas are peaking around 17 ft just northeast of the center. A 1330 UTC Sentinel 6-A pass observed 12 ft or higher seas along a swath from 19N53W to 21N54W. Isolated moderate convection is well removed from the center from 14N-28N between 40W-50W. The motion toward the WNW is expected to continue over the next couple days, followed by a northwestward turn this weekend. Little change in strength is forecast during the next 48 hours, but some gradual intensification is forecast over the weekend. 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 is near 30W from 23N southward, moving west around 15-20 kt. Scattered moderate and isolated strong convection is noted from 13N-17N between 26W-31W. A central Caribbean Sea tropical wave is near 73W from 22N southward across Hispaniola to western Venezuela, moving west at 15 to 20 kt. Isolated moderate convection is occurring from 15N-18N between 68W-74W. A western Caribbean Sea tropical wave is near 89W from 20N southward, moving west around 10 kt. Scattered moderate and isolated strong convection is noted from 16N-21N west of 83W. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic near 19N16W over coastal Mauritania to 07N35W. Scattered moderate to isolated strong convection is noted from 04N-15N east of 25W, and from 03N-09N between 25W-43W. ...GULF OF AMERICA... A surface trough extends from 19N96W to 24N97W along the coast of NE Mexico. Scattered moderate convection is noted from 22N-26N west of 93W. Another surface trough extends from 25N93W to 27N88W with isolated moderate convection from 27N-28N between 88W-91W. Away from the thunderstorms, winds are moderate or weaker across the Gulf with seas 2-5 ft. For the forecast, high pressure centered north of the region will dominate the basin into the weekend, supporting gentle to moderate east winds along with slight seas. A mid to upper level trough over the far southeastern Gulf will continue to maintain unsettled weather over this part of the Gulf through Fri. ...CARIBBEAN SEA... Refer to the section above for details on the tropical waves moving across the basin. An upper-level trough between the Lesser Antilles and Bermuda is helping to force scattered moderate and isolated strong convection from 15-20N between 63W-67W. Away from the thunderstorms, the trades are moderate or weaker across the Caribbean due to a weak north-south pressure gradient. Seas are 2-4 ft. For the forecast, the convective activity associated with the tropical waves is forecast to gradually shift WNW through late Fri. Gentle to moderate trades along with moderate seas are expected are through the rest of the period. ...ATLANTIC OCEAN... Refer to the sections above for details on Tropical Storm Gabrielle and the tropical wave moving across the eastern Atlantic. Away from Tropical Storm Gabrielle, there is a weak pressure gradient between ridging near 31N and lower pressure over the ITCZ/monsoon trough. This pressure gradient is forcing only gentle to moderate trades with seas 3-7 ft. Scattered moderate and isolated strong convection is north of 25N between 74W-80W in association with a pair of troughs near the Bahamas. For the forecast west of 55W, Gabrielle will move to near 21.1N 53.2W this evening, to near 22.1N 55.3W Fri morning, to near 23.2N 57.4W Fri evening with maximum sustained winds 40 kt gusts 50 kt, to near 24.4N 59.2W Sat morning, to near 25.9N 60.6W Sat evening, and continue to gradually strengthen as it moves to near 27.7N 61.5W Sun morning with maximum sustained winds 50 kt gusts 60 kt. Gabrielle is forecast to intensify into a hurricane near 31.4N 61.9W early Mon and continue to strengthen as it moves well N of the area to near 36.5N 56.2W by early Tue. Central Atlantic high pressure will build westward in its wake generally 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. $$ Landsea/Aguirre