000 AXNT20 KNHC 172359 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0015 UTC Fri Apr 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough axis enters the Atlantic near the coast of Gambia at 13N17W and continues southwestward to 05N20W, where it transitions to the ITCZ and continues to 01N30W and to the coast of Brazil near 02N51W. Scattered moderate convection is within 120 nm north of the ITCZ between 40W and 51W. ...GULF OF AMERICA... High pressure stretches from Mid-Atlantic region southwestward to over the basin. The gradient between the high pressure and low pressure in the Plains is allowing for fresh to strong southerly winds to exist in the far western Gulf. Seas are 5 to 7 ft with these winds. Fresh wind are elsewhere, except for moderate winds in the north-central section, and light and variable winds in the NE Gulf. Seas are 4 to 6 ft elsewhere except 2 to 4 ft in the north-central and NE Gulf sections. No significant deep convection is occurring this evening. For the forecast, fresh to strong northeast winds will pulse offshore of the Yucatan Peninsula and in the eastern Bay of Campeche through this weekend as a trough develops daily and moves westward. Elsewhere, fresh to locally strong SE winds will develop west of 90W tonight as a low pressure system strengthens in the central United States. By Fri, fresh to locally strong SE winds are expected across much of the basin, including through the Florida Straits, as the pressure gradient strengthens between the aforementioned low and building high pressure over the western Atlantic. Seas will slowly build through this weekend, with rough seas possible near the strong winds by early Sat. Looking ahead, winds and seas will slowly diminish next week. ...CARIBBEAN SEA... A moderate pressure gradient between high pressure off the southeastern United States and low pressure of 1007 mb in northwest Colombian Low is allowing for fresh to strong trades to be in the south-central Caribbean. Gentle to moderate trades are elsewhere. Seas are 6 to 9 ft in northeast to east swell in the southwestern Caribbean and 3 to 6 ft elsewhere, except 5 to 7 ft in the west-central section. Scattered showers are possible north of 15N between 65W and 68W, otherwise no significant deep convection is occurring over the Caribbean this evening. For the forecast, strong high pressure north of the basin will support fresh to strong northeast winds across the central and western Caribbean tonight into early next week, including the Windward Passage and south of Cuba. Near-gale force winds may pulse off Colombia during the overnight hours, accompanied by rough seas. Large northerly swell will impact the Mona and Anegada passages in the northeastern Caribbean by late Sun. Looking ahead, winds and seas are expected to diminish starting Tue as the high pressure north of the area weakens. The weather pattern is expected to become unstable in the northeastern Caribbean through the weekend as troughing sets up over that part of the area and while at the same time low-level convergence increases. ...ATLANTIC OCEAN... A cold front extends from 31N61W to 29N65W, where it becomes stationary to 27N70W and to the central Bahamas. Satellite imagery shows scattered showers and isolated thunderstorms north of 29N between the front and a trough that extends from 31N55W southwestward to 26N62W and to near 23N68W. Scattered showers and thunderstorms are seen within about 180 nm southeast of the trough from 23N to 27N. Elsewhere, a moderate pressure gradient between high pressure of 1029 mb that is well north of the area at 34N40W and relatively lower pressure to the south is generally inducing moderate to fresh trades south of 28N and east of 60W. Fresh to strong northeast winds are near the Canary Islands and Western Sahara along with seas of 8 to 10 ft. Seas are about 5 to 8 ft in mixed swell elsewhere across the tropical N Atlantic. For the forecast west of 55W, the aforementioned cold front will weaken as it slowly drifts southward through Fri as high pressure builds in its wake. The stationary portion will weaken and dissipate by Fri night. A tightening pressure gradient between these features will support an expansive area of strong northeast to east winds and rough seas are expected Sat into Sun through the Bahamas and near the Greater Antilles. Winds and seas will slowly diminish west of 65W early next week. Looking ahead, a complex low pressure system may develop in the central Atlantic this weekend, producing fresh to strong northeast winds and rough seas surrounding the low, east of 65W. $$ Aguirre