


Tropical Weather Discussion
Issued by NWS
Issued by NWS
966 AXNT20 KNHC 170604 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0615 UTC Fri Oct 17 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 0000 UTC surface analysis and satellite imagery through 0545 UTC. ...SPECIAL FEATURES... Atlantic Large Swell Event: Northerly swell generated from a developing storm force low over the Atlantic waters north of the discussion area will support rough to very rough seas over the western Atlantic through this weekend. Very rough seas in excess of 12 ft will propagate into the discussion waters between 60W and 70W beginning today. The area of 12 ft and greater seas will spread southeastward on Sat, covering the waters north of 27N between 50W and 69 by Sat night. The swell will then start to subside over the discussion waters allowing or seas to drop below 12 ft Sun night. Seas with this swell will peak near 18 ft over the waters north of about 30N between 55W and 65W on Sat. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...TROPICAL WAVES... The axis of a central Atlantic tropical wave is near 38W from 05N to 17N, moving westward at about 15 to 20 kt. Its position is based on satellite imagery animation, further corraborated by a recent ASCAT satellite data pass. Numerous moderate to strong convection is within 120 nm either side of the wave from 08N to 11N. Scattered moderate to isolated strong convection is within 180 nm east of the wave from 11N to 14N. Some gradual development of this system is possible over the next several days as it continues westward. Regardless of development, heavy rainfall and gusty winds are possible as the system moves across the Windward Islands late this weekend and enters the Caribbean Sea by the early to middle part of next week. The axis of a central Atlantic tropical wave is near 50W from 04N to 16N. It is moving westward near 15 kt. Scattered moderate to strong convection is seen within 120 nm either side of the wave from 08N to 11N. ...MONSOON TROUGH/ITCZ... The monsoon trough axis enters the Atlantic near 12N16W and extends southwestward to near 06N21W, where it transitions to the ITCZ to 06N25W and northwestward to 08N35W. Aside from convection noted in the tropical waves section, scattered moderate to isolated strong convection is noted from 01N to 05N between 26W-31W, within 180 nm south of the ITCZ between 23W-26W and within 120 nm south of the trough between 17W-20W. Scattered moderate convection is along and just offshore the coast of Africa from 06N to 10N. ...GULF OF AMERICA... A surface trough extends from the central Gulf near 26N95W southeastward to southeastward to the northeast part of the Yucatan Peninsula and to the northwestern Caribbean Sea. Isolated mostly weak showers are within 60 nm east of the trough from 23N to 26N and northwest of the trough from 26N to 29N between 93W and 96W. Otherwise, relatively weak high is present over the NE and north-central Gulf sections. The associated pressure gradient is generally supporting gentle to moderate northeast to east winds from 24N to 28N east of 94W. Seas are 3 to 4 ft with these winds. Light to gentle winds are elsewhere along with seas of 2 to 3 ft, except for lower seas of 1 to 2 ft in the west-central and SW portions of the basin. For the forecast, the aforementioned high pressure will dominate the Gulf region through early next week, resulting in gentle to moderate winds and slight to moderate seas over much of the basin. A cold front may reach the northern Gulf waters by Sun nigh and stall over the northern waters early next week. ...CARIBBEAN SEA... A frontal trough extends from NW Haiti, to just south of eastern Cuba, and to just east of the northeast portion of the Yucatan Peninsula. Satellite imagery shows clusters of scattered showers and thunderstorms along and near this boundary. Recent scatterometer satellite data passes indicate mostly gentle north to northeast winds north of the boundary, with the exception of moderate to fresh northeast winds in the lee of Cuba to near the coast of Cuba between 78W and 79W, and also between 80W and 82W. A weak pressure gradient prevails across the rest of the Caribbean waters. Gentle to moderate south winds are noted over the far eastern Caribbean, with light to gentle winds elsewhere. Seas remain in the 2 to 4 ft range in the far eastern Caribbean, and 2 ft or less elsewhere. For the forecast, a weak pressure gradient will support moderate or lighter winds and slight to moderate seas over much of the basin through Sat. A tropical wave will move across the tropical Atlantic waters late this weekend with fresh to strong winds, and rough seas accompanying the wave. The tropical wave is forecast to enter the Caribbean waters by early next week, bringing fresh winds and rough seas over the eastern Caribbean waters. ...ATLANTIC OCEAN... Please refer to the Special Features section for further details on a large swell event that will begin to impact some sections of the north-central waters today. A central Atlantic cold front is analyzed from near 31N52W southwestward to 24N60W, where it transitions to a stationary front that continues southwestward to just inland northern Hispaniola. Clusters of scattered showers and thunderstorms, some heavy, are along both the cold and stationary the fronts as well as within about 240 nm east-southeast of the fronts. Fresh to strong southwest winds are east and southeast of the fronts to near 45W and north of 19N. Seas with these winds are 8 to 12 ft, with the highest of the seas north of 27N between 48W and the front. Moderate to locally fresh northwest winds and locally rough seas are west of the front. To the NW of the front, another cold front extends from near 31N62W southwestward to 28N68W and to near the northern Bahamas. Fresh to strong northwest to north winds are behind this front to 74W, and fresh north to northeast winds are west of 74W. Seas are 7 to 11 ft in north to northeast swell behind the front north of 28N. Fresh north to northeast winds are behind the front from 26N to 28N along with seas of 6 to 9 ft in northeast swell. Elsewhere, a surface trough extends from near 30.5N33W to 28N35W and to 24N36W. Gentle to moderate west to northwest winds are within the surrounding environment of this trough, and seas of 8 to 12 ft are 24.5N38W, and fresh to strong winds and 8 to 10 ft seas are noted in the vicinity of this trough. A 1018 mb high is located near 24N30W. Its associated ridge extends west- southwestward to just east of the Lesser Antilles. The related gradient is producing gentle to moderate trade winds south of 20N to near 17N between 26W and 48W, and mostly northeast to east winds from 10N to 20N between 26W and 48W. Seas are 5 to 7 ft with these winds, except for 4 to 6 ft seas from 10N to 20N between 26W and 48W. Latest scatterometer satellite data passes indicate fresh to strong north winds between the coast of W Africa and 20W. Seas are 7 to 8 ft within this area. Seas are 3 to 5 ft elsewhere over the region. For the forecast W of 55W, a series of cold fronts will move across the forecast waters through Sat. High pressure will then build in the wake of the fronts. Fresh to strong winds are expected over the waters north of about 25N through Sat before winds diminish. The fronts will usher in northerly swell across the forecast waters. Rough seas will cover the waters N of 25N through the end of the week, before spreading southward to cover much of the waters east of 70W by early Sun. Seas will then subside from west to east the remainder of the weekend into early next week. Very rough seas will move into the waters north of 27N and east of 70W from early on Fri through Sun morning. $$ Aguirre