Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 0615 UTC Wed Mar 18 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 0400 UTC. ...SPECIAL FEATURES... East Atlantic Long-period N Swell: Large, long-period N swell generated by a large fetch of gale to storm-force winds in the northeast Atlantic will continue to propagate southward of 31N through Wed. Expect seas of 12 and 20 ft from 25N to 31N between 16W and 45W overnight. These seas will shift farther southward to near 23N Wed morning, and then become reinforced with additional large N swell Wed through Thu. Seas across these northeastern waters will remain 12 ft and greater through at least Fri night. 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 enters the Atlantic near 12N17W, then curves southwestward to 04N22W. The ITCZ continues from 04N22W to 03S40W. Scattered moderate convection is noted within 300 nm N of the ITCZ. ...GULF OF AMERICA... A 1025 mb high pressure centered over southern Louisiana is building across the basin. Fresh to strong NE winds dominate the SE half of the basin, with winds diminishing to gentle to moderate to the NW. Seas are rough where the winds are fresh to strong, with some very rough seas to 12 ft in the Yucatan Channel. Elsewhere, moderate seas prevail. For the forecast, N to NE fresh to strong winds and rough seas associated with the passage of a cold front will diminish by Wed morning. In the wake of the front, high pressure will build across the region and prevail into the weekend. ...CARIBBEAN SEA... A stationary front extends across the W Caribbean from 22N82W to 19N88W. Scattered moderate convection prevails along the front. N of the front, strong to near gale-force NE winds and rapidly building rough seas exist. Elsewhere across the NW and SW basin, winds are moderate or weaker and seas are moderate. Across the central basin, fresh to strong winds and seas of 8 to 10 ft prevail, with fresh winds and moderate seas farther east. For the forecast, fresh to strong trade winds and rough seas will prevail across the waters near the Lesser Antilles, and the eastern and central Caribbean, including the Atlantic exposures and Passages through Wed. The stationary front over the far NW Caribbean will continue to weaken before dissipating on Wed. This should decrease the influence from the ridge and allow winds and seas across the central and eastern Caribbean to gradually diminish through Sat. ...ATLANTIC OCEAN... A cold front extends from 31N71W to the Central Bahamas, then becomes stationary and continues to central Cuba. A band of numerous moderate to isolated strong convection exists in the vicinity of the front mainly W of 66W. Behind the front, moderate to fresh N winds and moderate to rough seas prevail. E of the front, an expansive surface trough dominates the basin, anchored by a 1037 mb high pressure at 38N46W. These is leading to widespread fresh to strong NE to E winds, with moderate to rough seas. To the E, the tail end of a cold front extends from 31N18W to 29N20W. A surface trough is analyzed ahead of the front from 31N15W to 25N18W. No significant convection is noted with these features For the forecast west of 55W, by Wed afternoon, the front will stall from near Bermuda to the central Bahamas. A weak low pressure system is forecast to develop along the stationary front, tightening the pressure gradient and supporting fresh to strong winds with rough to very rough seas affecting the offshore waters N of 25N through the rest of the week as this system then transitions to a cold front and moves east of the area.