000 AXNT20 KNHC 250004 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Thu Nov 25 2021 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 1800 UTC surface analysis and satellite imagery through 2350 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough is mostly confined to the African continent, reaching the Atlantic through the coast of Sierra Leone near 07N13W. The ITCZ extends from 07N13W to 04N29W to 01N45W. Scattered moderate convection from 03N to 10N and between 21W to 30W. GULF OF MEXICO... A strong 1030 mb high pressure system anchored over the Appalachian Mountains extends into the Gulf of Mexico. Dry continental airmass continues to dominate the region and no significant convection is observed. Recent scatterometer satellite data and surface observations indicate that moderate to locally fresh anticyclonic winds are found across the basin, with the strongest winds occurring in the NW and E Gulf, including the Florida Straits. Seas of 6-9 ft are present in the SE Gulf, with the highest seas occurring in the Florida Straits and the entrance of the Yucatan Channel. For the forecast, fresh S winds are expected in the NW Gulf and fresh E winds in the Florida Straits will prevail ahead of a cold front that will move off the Texas coast Thu. By Fri evening, the front will reach a Fort Myers, Florida, to Veracruz, Mexico line. Fresh to strong winds are expected behind the front over the western Gulf Thu night into Fri night with near- gale force winds possible in the nearshore waters between Tampico and Brownsville. Winds will become light to gentle on Sat. CARIBBEAN SEA... A cold front extends from the open Atlantic to the north-central Caribbean Sea, where it becomes a stationary front that stretches to the Nicaraguan coast. A few showers are noticed near the frontal boundary, but no deep convection is associated with this feature. The latest satellite-derived wind data shows fresh to locally strong NE winds behind the frontal boundary. Seas of 3-6 ft are also found behind the front. Elsewhere, scattered showers and isolated thunderstorms affect the Southern Caribbean Sea from Colombia and NW Venezuela. This is likely associated with the eastern extension of the E Pacific monsoon trough that is enhancing the development of convection in the region. Moderate or weaker winds and seas of 1-3 ft are prevalent ahead of the front. For the forecast, the cold front from Dominican Republic to Nicaragua has stalled this afternoon. The front will gradually dissipate through the remainder of the week. Fresh NE winds will prevail behind this front, with some locally strong winds possible S of Hispaniola and in the Windward Passage tonight. Showers and thunderstorms will increase over Hispaniola and Puerto Rico through Fri and bring a potential for heavy rain. Moderate northerly swell will affect the NE Caribbean passages and the Tropical N Atlantic waters Thu into Sat. ATLANTIC OCEAN... An cold front extends from a strong extratropical cyclone near Nova Scotia to Hispaniola, entering the tropical Atlantic near 30N55W. A few showers are seen near the frontal boundary, N of 22N to 31N, however, the strongest convection is found north of our area. Fresh to strong northerly winds are occurring behind the cold front, with the strongest winds prevailing N of 28N and E of 71W. Northerly swell behind the cold front result in a large area of 8-16 ft seas, with 12 ft or higher seas prevailing N of 27N and between 60W to 71W. Farther east, a surface trough extending from 29N28W to 17N37W and divergence aloft results in scattered showers and thunderstorms N of 21N and between 21W and 29W. Scatterometer satellite data depict fresh to strong southerly winds N of 21N and between 23W and 30W. However, stronger winds can be found associated with the heaviest thunderstorms. Seas of 6-9 ft are present N of 18N and between 25W and 55W. Elsewhere, fairly tranquil weather conditions, moderate or weaker winds and seas of 4-7 ft prevail. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Marine and aviation interests should monitor this ongoing situation by reading the Volcanic Ash Advisory issued by Meteo-France, at http://vaac.meteo.fr/volcanoes/la-palma/. For the forecast W of 55W, a cold front stretches from 31N55W to Dominican Republic. The northern portion of this front will move east of the area, while the southern part will stall along 19N into the weekend. Fresh NE winds can be expected behind the front, with some strong winds N of 28N through Thu. In the wake of the front, high pressure will build in off the coast of Georgia and northern Florida on Thu. The next cold front will push off the NE Florida coast Thu night and bring another round of strong winds into Sat N of 29N. $$ Torres