Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1815 UTC Tue Oct 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 1200 UTC surface analysis and satellite imagery through 1750 UTC. ...SPECIAL FEATURES... Former tropical wave (AL98) has evolved into Tropical Storm Melissa, which is centered near 14.3N 71.7W at 21/1500 UTC or 260 nm S of Port Au Prince Haiti, moving W at 12 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Peak seas near the center are 13 ft. Numerous moderate to strong convection extends from 11N to 16N between 66W and 72W. Scattered moderate convection is elsewhere from 10N to 19N between 63W and 73W. Melissa is expected to have a decrease in forward speed and a gradual turn to the northwest and north during the next few days. On the forecast track, Melissa is expected to approach the southwestern portion of Haiti and Jamaica later this week. Gradual strengthening is expected during the next few days. Swells generated by Melissa are expected to spread to Hispaniola, Jamaica, and eastern Cuba during the next couple of days. 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 Melissa NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave extends from 03N to 15N with axis near 34W, moving west at 5 to 10 kt. Scattered moderate convection is noted from 04N to 16N between 30W and 37W. A tropical wave is E of the Lesser Antilles, extending from 08N to 18N, with axis near 55W, moving west at 10 kt. Widely scattered showers are ongoing from 09N to 18N between 50W and 60W. A tropical wave in the western Caribbean Sea south of 18N with axis near 82W, moving westward at 10 to 15 kt. Scattered moderate isolated strong convection is noted from 09N to 14N between 80W and 86W. ...MONSOON TROUGH/ITCZ... The monsoon trough enter the Atlantic Ocean near 09N14W and continues southwestward to 06N20W to 07N28W. The ITCZ extends from 06N41W and continues to 06N58W. Scattered moderate convection extends from 02N to 15N between 14W and 30W. ...GULF OF AMERICA... A 1020 mb high over southern Alabama extends a ridge over the Gulf and supports light to gentle variable winds and slight seas to 3 ft. There are three surface troughs in the basin, one over the NE, the central and SW Gulf, however, all devoid of shower activity. For the forecast, a cold front will move into the Texas coastal waters by this evening, then shift eastward and reach from near Cedar Key, Florida to Corpus Christi, Texas by Wed morning. The front will move farther south over the eastern Gulf through Wed, while lifting northward over the western Gulf, and will reach from Tampa Bay, Florida to Galveston, Texas by Thu morning. The front will stall from the Florida Keys to Sabine Pass, Louisiana by Fri morning, then dissipate over the western Gulf through Sat. This pattern will support fresh NE to E winds and moderate to rough seas across the southeast Gulf later in the week. ...CARIBBEAN SEA... Please see SPECIAL FEATURES section above for more on a Tropical Storm Melissa. Newly formed Tropical Storm Melissa is near 14.3N 71.7W at 11 AM EDT, and is moving west at 12 kt. Maximum sustained winds are 45 kt with gusts to 55 kt, and the minimum central pressure is 1003 mb. Aside from Melissa, scattered showers and tstms are over the NW Caribbean due to a surface trough that extends from just east of the Youth Island SW to southern Belize coastal waters. Scatterometer data show fresh to locally stron NNE winds in the northern portion of the trough where the strongest tstms are likely ongoing. In the SW Caribbean, a tropical wave is generating heavy showers and tstms over the Nicaragua and Costa Rica offshore waters. For the forecast, Melissa will move to 14.4N 72.8W this evening, 14.8N 73.5W Wed morning, and 15.3N 74.2W Wed evening. Melissa will move to 15.7N 74.5W Thu morning, 16.1N 74.6W by Thu evening, and then approach southwest Haiti near 16.5N 74.5W Fri morning. Melissa will strengthen to a hurricane southwest of Haiti near 16.9N 74.5W early Sat. Otherwise, convection associated with the tropical wave and the surface trough should dissipate early tonight. ...ATLANTIC OCEAN... A stationary front extends from 31N74W to just north of Grand Bahama Island. The remainder subtropical Atlantic is under the influence of the Azores and Bermuda Highs, except for the central waters, where a pair of trough are enhancing some showers. Winds are moderate or weaker and seas are moderate, except for locally fresh N of Puerto Rico and Hispaniola. For the forecast W of 55W, the stationary front will dissipate today. A second cold front will move off the coast of Florida Wed morning, continue to move southeastward through mid week, before stalling from near Bermuda to the Florida Keys by Fri night. Meanwhile, Tropical Storm Melissa in the south-central Caribbean is forecast to move slowly north to off southwest Haiti by Thu. This pattern will support fresh to strong E to SE winds over the waters south of 22N and west of 70W late Wed into Fri. Depending on the track of Melissa and the extent of its wind field, tropical storm conditions are possible near the northern approaches to the Windward Passage Sat.