776 AXNT20 KNHC 261719 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Tue Nov 26 2024 Tropical Weather Discussion for North America, Central America Gulf of Mexico, 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 1200 UTC surface analysis and satellite imagery through 1530 UTC. ...SPECIAL FEATURES... ...LONG PERIOD SWELL AND ROUGH TO VERY ROUGH SEAS... Long-period NW swell with 12-15 ft seas is moving through the north central Atlantic Ocean in the wake of a cold front that extends from 31N36W to 24N52W. A reinforcing cold front will move into the area today followed by a second set of 12-16 second NW swell with seas to 16 ft, which will propagate through the waters north of 25N east of 55W through Thursday. Please, read the latest HIGH SEAS FORECAST, that is issued by the National Hurricane Center, at the website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, for details. ...EXCESSIVE RAINFALL IN THE NORTHERN CARIBBEAN SEA... A slow-to-progress potent and large upper trough extends across the Florida peninsula into the western Caribbean. This system is helping to force the development of a surface trough extending from the southern Bahamas to western Haiti. Numerous moderate and scattered strong convection is occurring currently from 12N-20N between 75W-80W. Two to three days of intermittent periods of heavy rain, frequent lightning, and gusty winds are expected under this scenario, as a weak low pressure develops in the region today and meanders through Wed. The extended period of heavy rain will increase the risks for flash flooding and mudslides for portions of Jamaica, Haiti, the southern Bahamas, and the Turks and Caicos. This information was provided by the International Desk meteorologists at the WPC. Please, refer to the WPC, and/or to your country's local meteorological agency for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains border of Sierra Leone near 08N13W to 07N17W. The ITCZ continues from 07N17W to 01N50W. Isolated moderate convection is noted from 03N-06N between 20W-40W. ...GULF OF MEXICO... As of 1500 UTC, a cold front extends from coastal Alabama southwestward to the Mexico coast near 25N97W followed by moderate NE winds and preceded by moderate SW winds over the NE Gulf coastal waters. A broad 1022 mb high centered near 27N88W and associated ridge cover the remainder of Gulf waters. The pressure gradient between the ridge and a broad area of low pressure in the western Caribbean support moderate NE winds across the SE Gulf and the E Bay of Campeche. Seas basinwide are slight. For the forecast, the cold front will reach from the Florida Big Bend to the north-central Gulf near 27N90W tonight, then lift N of the area on Wed. A second cold front is forecast to enter the NW Gulf waters Thu morning. Moderate to fresh southerly winds will develop over the western Gulf tonight through Wed night ahead of the second front, which will reach from Cedar Key, Florida to near Tampico, Mexico early on Fri morning, and from the Straits of Florida to near Veracruz, Mexico by Sat morning. The front will exit the basin by Sat evening. Fresh to strong northerly winds and building seas will follow this front. Winds may briefly reach minimal gale force near the Veracruz area on Fri. ...CARIBBEAN SEA... Please, read the SPECIAL FEATURES section, for details about a heavy rainfall event. Aside from the trough and heavy rain feature described above, a moderate pressure gradient is forcing moderate to fresh trades across most of the Caribbean. Over the SW Caribbean a broad 1010 mb low is centered near 12N80W with a surface trough extending north-northwestward to near Swan Island and winds only light to gentle equatorward of the low. Seas are slight to moderate across the basin. For the forecast, a tightening pressure gradient between developing low pressure in the SW Caribbean and high pressure building over the SW N Atlantic will support fresh to strong NE winds in the Windward Passage, and fresh to strong NE to E winds across the central Caribbean today. Moderate to locally fresh trades are forecast basin-wide the remainder of the forecast period, except in the lee of eastern Cuba where fresh to locally strong NE winds are predicted beginning on Tue as a low pressure develops in the vicinity of the SE Bahamas. The low pressure will open up into a trough on Thu while winds diminishing in the lee of Cuba. ...ATLANTIC OCEAN... Please, read the SPECIAL FEATURES section, for details about very large, long-period swell event as well as the heavy rainfall event that extends northward into the southern Bahamas. A cold front extends from 31N36W west-southwestward to 23N52W, where it transitions to a trough reaching to 23N67W. No significant convection is noted in association with the cold front or trough. Winds on either side of the front are fresh to strong north of 29N. In addition to the very large seas described above, seas of at least 8 ft in NW swell extend down to 21N between 30W and 60W. A weak surface ridge extends from 31N20W to 25N45W. Equatorward of the ridge, the E trades are moderate to fresh with seas moderate. Elsewhere across the basin, winds are moderate or weaker and seas are slight to moderate. For the forecast, a ridge will dominate the north waters while a surface trough remains near the SE Bahamas. Fresh to strong winds are expected on the west side of the trough today. The trough will move westward, reaching the central Bahamas and eastern Cuba by Wed night, and the NW Bahamas and central Cuba late on Thu before weakening. The next cold front will enter the NE Florida offshore waters tonight before stalling and lifting N of the area late Wed. Another cold front is forecast to move offshore NE Florida Thu night into Fri, extending from 31N70W to south Florida by Sat morning, and from 31N60W to western Cuba by Sun morning. Moderate to fresh winds and moderate seas will follow the front. $$ Landsea