Atlantic Tropical Weather Discussion
966 AXNT20 KNHC 200401 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0615 UTC Tue Oct 20 2026 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 0355 UTC. ...SPECIAL FEATURES... Atlantic Significant N Swell: A 1004 mb low pressure centered between the Outer Banks and Bermuda continues to produce a large area of strong to gale-force winds north of our area. A cold front extends from this low to 31N67W and to 26N71W, followed by a stationary front to the Florida Straits and central Gulf of America. Fresh to locally strong northerly winds and rough to very rough seas, peaking around 15 ft, are noted behind the frontal boundaries. These seas will continue to gradually decay tonight, but remain above 12 ft into Tue. Seas to 8 ft will persist thereafter over the waters west of 65W and north of 25N through Thu night. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZNT02 KNHC/HSFAT2 or at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for further details. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of The Gambia near 13N17W and continues west-southwestward to 07N31W. The ITCZ extends from 07N31W to 08N45W and to 08N60W. Scattered moderate to isolated strong convection is observed from 05N to 12N and east of 30W. ...GULF OF AMERICA... The stationary front depicted from Matanzas, Cuba to the Bay of Campeche is dissipating. Divergence aloft and abundant tropical moisture south of the front supports scattered showers and some thunderstorms near the frontal boundary, mainly west of 87W, and over parts of the Yucatan peninsula. The rest of the basin is engulfed in a dry continental airmass that suppresses deep convection and supports stratocumulus clouds as the colder air moves over the warmer waters. The tight pressure gradient between the strong high pressure over the eastern United States and lower pressures in the deep tropics forces fresh to near gale-force NW winds and rough seas to 10 ft in the SW Gulf. Fresh to strong NE winds and seas of 4-8 ft are also noted in the eastern and northern Gulf waters. Moderate to fresh and seas of 4-8 ft are found in the rest of the western waters. In the eastern Bay of Campeche, light to gentle winds and moderate seas are prevalent. For the forecast, the aforementioned front will dissipate through Tue, and high pressure over the eastern U.S. will support moderate to fresh winds and moderate seas across the basin into the latter part of the week. Looking ahead, building high pressure over the eastern U.S. will support increased NE winds and building seas over the eastern Gulf Sat. ...CARIBBEAN SEA... Plenty of tropical moisture and strong upper-level winds combine to produce scattered showers and isolated thunderstorms across the SW Caribbean, also affecting the countries in the area. Diurnal heating has also supported some storms over the Greater Antilles. A weak pressure gradient is found across much of the basin, supporting mainly moderate or weaker winds and slight to locally moderate seas. However, the gradient is a bit tighter near South America, sustaining moderate to locally strong easterly trade and seas of 3-6 ft. For the forecast, strong high pressure over the eastern U.S. will support moderate to fresh NE winds across the far northwest Caribbean and Yucatan Channel through late Tue. These winds will diminish by mid week as the high pressure weakens, leaving gentle to moderate winds and slight to moderate seas across the basin through mid week. Looking ahead, expect moderate to fresh winds across the south-central Caribbean by Thu, and fresh winds across the far northwest Caribbean by late Sat as high pressure builds again north of the area. ...ATLANTIC OCEAN... See the Special Features section above for information on significant north swell behind a cold front in the western Atlantic. A broad upper-level low near 25N53W is producing a large area of showers and isolated thunderstorms from 20N to 31N and between 41W and 59W. At the surface, the pressure gradient between a strong ridge off Newfoundland and a couple of surface troughs in the central Atlantic supports moderate to locally strong easterly winds and seas of 5-9 ft north of 26N and between 40W and 65W. Another surface trough is analyzed along 44W, south of 20N, and a few showers are evident near this boundary. In the far NE waters, a weak surface trough and east-west surface trough support some shower activity near the western Canary Islands. Elsewhere, broad high pressure dominates sustaining moderate or weaker winds and moderate seas. For the forecast west of 55W, moderate to fresh N to NE winds and rough to very rough seas persist west of a frontal boundary reaching from 31N67W to the central Bahamas to northwest Cuba. The front is stalling, and will dissipate into mid week. Winds will diminish through Tue, and lingering swell will subside through Thu. Looking ahead, a tightening pressure gradient developing late Fri is expected to induce widespread near to gale-force NE winds over the waters N of about 25N well into the weekend. Seas with these winds are expected to quickly build to rough to very rough. Mariners should monitor the latest marine forecasts, and have avoidance plans in place.