Tropical Weather Discussion

Full Alert Message

Tropical Weather Discussion NWS National Hurricane Center Miami FL 0015 UTC Sat Mar 21 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... East Atlantic Gale Warning: According to the latest Meteo-France forecast, a gale warning for winds gusting to gale-force for the high seas zone of the eastern portion of Irving until 21/12 UTC. Please refer to the next Special Feature for details on associated very large swells. Please refer to the high seas forecast issued by Meteo- France on the website: https://wwmiws.wmo.int for more details. East Atlantic Long-period N Swell: Very large, long-period north swell generated by a large fetch of gale-force winds in the northeast Atlantic will continue to propagate southward of 31N through Sun. Expect seas of 12-21 ft tonight, subsiding to 12 to 16 ft on Sat, mainly N of 19N and east of about 38W. Seas over these northeastern waters will gradually diminish in areal coverage with the remaining very rough seas subsiding below 12 ft near the Canary Islands Mon. Please refer to the latest High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough axis enters the Atlantic through the coast of Liberia near 06N11W and continues southwestward to 04N17W, where it transitions to the ITCZ to 02N35W to just inland Brazil. Scattered moderate convection is noted within 120 nm N of the ITCZ between 25W and 35W and from 02N to 05N between 44W and the coast of Brazil. ...GULF OF AMERICA... A 1023 mb high center is over the north-central Gulf near 29N88W, with a ridge extending southwestward to the west-central Gulf. The pressure gradient between this ridge and a stationary front SE of the area is leading to fresh N to NE winds across the SE Gulf, along with seas of 4 to 7 ft. Moderate or weaker winds and slight to moderate seas are elsewhere. For the forecast, the pressure gradient between a ridge across the Gulf region and a stationary front over the central Caribbean Sea will continue to support fresh to locally strong NE winds and moderate to rough seas over the SE Gulf, including the Straits of Florida, through tonight. Moderate to fresh NE winds are expected nightly, through the forecast period, across the eastern Bay of Campeche due to local effects associated with a thermal trough. Elsewhere, moderate or weaker winds, and slight to moderate seas will prevail through Tue. Winds may briefly increase to fresh speeds over the NE Gulf late Tue into early Wed as the pressure gradient tightens there. ...CARIBBEAN SEA... A stationary front extends from eastern Cuba to the offshore waters of northern Costa Rica. Fresh to locally strong north winds are west of the front, with seas of 5 to 7 ft. To the east, gentle to moderate east to southeast winds and slight to moderate seas prevail. For the forecast, fresh to locally strong N winds and moderate to rough seas will continue behind the stationary front, which is forecast to dissipate tonight. Afterward, moderate to locally strong NE winds will remain in the western Caribbean, including the lee side of Cuba and the Windward Passage through early Sun as high pressure develops across the northern Bahamas in the wake of the front. As the ridge shifts slightly eastward, fresh to strong winds and moderate to rough seas will develop offshore Colombia Sun night and prevail through Wed night. ...ATLANTIC OCEAN... Refer to the Special Features section for details on an east Atlantic Gale Warning issued by Meteo-France and associated large northerly swell that is impacting the far northeast waters of the discussion area. A stationary front extends SW from a 1011 mb low pressure center near 30N67W through the SE Bahamas and into eastern Cuba. A pre- frontal trough is parallel to the boundary to the east from around 29N64W to the Turks and Caicos. Numerous moderate convection exists along and east of the trough, N of 24N between 60W and 66W. The pressure gradient between the front and high pressure building toward the region from the SE U.S. is leading to fresh to strong N winds, with rough to very rough seas building from these winds. Winds are also increasing SE of the low pressure, ahead of the front and trough, with fresh S winds and building seas N of 26N extending E to 58W. In the east Atlantic, a dissipating cold front moving southward to near 20N, extending from Africa to around 35W. Fresh N winds are N of the boundary, with strong cyclonic winds N of 25N and E of 35W. See the Special Features section for the gale-force winds farther NE, as well as the very rough seas in the vicinity of this cold front. Rough seas in northerly swell in the east Atlantic extend southward to 10N and W to 57W, and are impacting the Cabo Verde Islands. For the remainder of the waters, S of 20N mainly moderate NE trades and seas dominate. N of 20N, ridging from a 1026 mb high centered near 38N42W is causing moderate to fresh easterly winds with 5 to 7 ft seas. For the forecast W of 55W, fresh to strong winds and rough seas on either side of the aforementioned front, and mainly N of 25N, will continue to affect the offshore waters from west to east through Sun as the front moves eastward as a cold front. This system is forecast to reach from 31N63W to Hispaniola by Sat morning, and from 31N57W to Puerto Rico by Sun morning. Looking ahead, a new cold front is forecast to enter the offshore waters of NE Florida Mon night into Tue, followed by fresh to strong NE to E winds and rough seas. These marine conditions are forecast to affect most of the waters N of 27N through the middle of the next week.