Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1815 UTC Sun Dec 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 1630 UTC. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic along the Sierra Leone coast near Freetown, then extends west-southwestward to 07N17W. An ITCZ continues from 07N17W across 05N35W to just east of French Guiana at 05N50W. Scattered moderate to isolated strong convection is noted near the ITCZ from 03N to 07N between 18W and 41W. ...GULF OF AMERICA... A surface trough is triggering scattered showers and isolated thunderstorms in the Bay of Campeche. Otherwise, a surface ridge stretching southwestward from a 1025 mb high over southeastern Georgia to near Tampico, Mexico is supporting gentle to moderate NE to SSE winds and 2 to 4 ft seas for the entire Gulf. For the forecast, moderate or weaker winds and slight seas will prevail over much of the Gulf through this evening. High pressure will build across the eastern United States through the day. This will tighten the pressure gradient across the Florida Straits, bringing an increase in winds. Fresh winds will develop over those waters tonight, and will strengthen Monday into late Tue. Rough seas will develop with the strong winds. ...CARIBBEAN SEA... Pressure gradient between the Atlantic Ridge and Colombian Low is sustaining a trade-wind regime across much of the Caribbean Sea. Convergent trades are causing widely scattered showers near Jamaica, Hispaniola and the Leeward Islands. Fresh to strong NE to ENE trades and seas of 8 to 10 ft exist at the south-central basin. Moderate to fresh ENE to E trades and 5 to 8 ft seas are present at the north-central and part of the southwestern basins. Gentle to moderate NE to E winds and seas at 3 t o 5 ft prevail for the rest of the Carribbean Sea. For the forecast, winds off Colombia will pulse to near gale- force at night. Rough seas are expected with these winds. High pressure will move off the coast of the United States in the wake of a cold front over the western Atlantic waters early this week. This will tighten the pressure gradient over the waters in the lee of Cuba, south of Hispaniola, and in the Windward Passage. Moderate to fresh NE winds over these waters will strengthen by Mon evening, and continue through Thu night. Otherwise, mixed long period swell over the tropical Atlantic waters will subside Mon evening. New long-period northerly swell will affect the tropical Atlantic waters during the middle of the week. ...ATLANTIC OCEAN... A weakening stationary front extends southwestward from the north-central Atlantic across 31N62W to the northwest Bahamas. Scattered showers are noted near and up to 75 nm northwest of this boundary. Farther east, two surface troughs are causing patchy showers north of 24N between 48W and 52W, and from 24N to 28N between 28W and 35W. Refer to the Monsoon Trough/ITCZ section for additional weather in the Atlantic Basin. Light to gentle with locally moderate NW to ENE winds and 4 to 6 ft seas in mixed moderate N to NE swells dominate north of 20N between 55W and the Florida/southern Georgia coast. To the east, Moderate with locally fresh NE to E winds and seas at 6 to 9 ft in large northerly swell exist north of 20N between 35W and 55W. For the tropical Atlantic from 06N to 20N and west of 35W, gentle to moderate with locally fresh NE to ENE winds and 6 to 8 ft seas in mixed N to NE swell exist. For the rest of the Atlantic Basin west of 35W, gentle SE to S winds and seas of 5 to 7 ft in mix moderate swells prevail. For the forecast W of 55W, moderate to occasionally fresh trade winds will prevail south of 22N through today. A cold front will move off the southeastern United States Mon morning, then progress rapidly southeastward across the western Atlantic through midweek. Widespread strong to locally near-gale force NE winds and rough to very rough seas are expected in the wake of the front. Very rough seas in excess of 12 ft will be possible east of 75W Tue through midweek. A second cold front may follow the path near midweek with strong winds and building seas in the wake of the front east of 70W.