000 AXNT20 KNHC 201803 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sat Nov 20 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 1200 UTC surface analysis and satellite imagery through 1740 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains of Sierra Leone near 08N13W, to 05N19W. The ITCZ continues from 05N19W, to 06N31W, and to 05N43W. A surface trough is along 15N37W 08N40W. Precipitation: scattered to numerous strong is within 160 nm to the north of the ITCZ between 26W and 30W, within 240 nm to the south of the ITCZ between 24W and 28W, in the southern coastal waters and inland sections of Liberia. Isolated moderate to locally strong is elsewhere to the south of the line 26N15W 25N24W 13N60W. GULF OF MEXICO... A cold front passes through the area of Lake Okeechobee of south Florida, to 25N86W in the Gulf of Mexico, to the SW corner of the Gulf of Mexico and the northern sections of the Isthmus of Tehuantepec of southern Mexico. Precipitation: broken to overcast multilayered clouds and widely scattered moderate to isolated strong are to the south of the line: 28N82W, 27N90W, to the coast of Mexico at 24N. A surface ridge extends from western Louisiana to an interior Mexico 1023 mb high pressure center that is near 23N99W. Fresh to strong winds are from 90W eastward. Moderate to fresh winds are elsewhere. The sea heights range from 5 feet to 7 feet to the south of the line: 30N86W 28N90W, 27N97W at the coast of Texas. The sea heights range from 2 feet to 4 feet elsewhere. A cold front extends from Tampa Bay, Florida to the central Gulf near 22N90W, to the south of Veracruz, Mexico. The front will drift southward, while dissipating today. High pressure will dominate the Gulf region in the wake of the front. Another cold front will enter the northwest Gulf early on Mon, and move to the south of the basin by Mon evening. Fresh to strong northerly winds are expected behind the front, mainly in the eastern Gulf, through Tue night. High pressure will follow the front. CARIBBEAN SEA... A surface trough is along 64W/65W, from 18N southward to the coast of Venezuela. The surface trough passes through the area that is between Anguilla and the Virgin Islands. Precipitation: isolated moderate from 21N southward between 60W and 70W. Precipitation: widely scattered moderate to isolated strong is within 180 nm to the north of the line 14N80W 13N82W 11N84W, from the waters that are about 200 nm to the east of NE Nicaragua, to the southeastern coastal plains and coastal waters of Nicaragua. Isolated moderate to locally strong is within 120 nm to the north of the line that runs from the southern coast of Haiti along 73W, to 14N80W. Isolated moderate covers the remainder of the area that is to the northwest of the line that runs from the southern coastal border of Haiti and the Dominican Republic to the coastal border of Nicaragua and Costa Rica. Isolated moderate rainshowers are associated with areas of broken low level clouds that are moving with the trade winds, in the remainder of the Caribbean Sea. The monsoon trough is along 09N/11N, from northern Colombia at 74W beyond Costa Rica. Precipitation: isolated moderate is within 60 nm on either side of the monsoon trough. Broad upper level anticyclonic wind flow covers the entire Caribbean Sea. Comparatively drier air in subsidence is apparent in water vapor imagery, to the east and the southeast of the areas of precipitation that are to the east of Nicaragua. Fresh to strong winds are within 100 nm to the north of the coast and Colombia between 74W and 76W. Moderate to fresh winds are from 17N southward between 70W and 80W. Gentle to moderate winds are elsewhere. The sea heights range from 2 feet to 4 feet from 79W westward,. The sea heights range from 4 feet to 6 feet between 60W and the Windward Passage. The sea heights range from 4 feet to 7 feet in the remainder of the Caribbean Sea. Mainly gentle to moderate trades will prevail across much of the Caribbean Sea during the next several days. A cold front will reach the Yucatan Channel by Mon evening, and extend from eastern Cuba to the Gulf of Honduras by late Tue. Fresh to locally strong winds and building seas are expected behind the front. ATLANTIC OCEAN... A cold front passes through Bermuda, to 30N71W, to Lake Okeechobee in the southern part of Florida. A surface trough is along 78W, from the coast of Cuba to the NW Bahamas. Precipitation: widely scattered moderate to isolated strong is within 600 nm to the southeast of the cold front. Upper level cyclonic wind flow covers the Atlantic Ocean from 20N northward from 50W eastward. The upper level trough that is in this area is supporting a cold front that is from 1000 nm to 1700 nm to the west of Africa. A surface trough is about 210 nm to the east of the cold front. Precipitation: isolated moderate to locally strong is within 240 nm to the east and southeast of the surface trough. Fresh winds are from 20N northward from 50W eastward, and from 66W westward. Moderate winds or lighter are elsewhere. The sea heights range from 6 feet to 9 feet from 20N northward between 20W and 60W. The sea heights range from 4 feet to 6 feet from 20N southward from 60W eastward. The sea heights range from 4 to 6 feet, mostly, from 60W westward, with some areas of 6 feet and 7 feet. 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/. A cold front, extending from 31N69W to near Cape Canaveral in Florida, will stall and remain across the northern forecast waters this weekend, before moving northward. This will happen in advance of a another cold front, that will move off the northeast Florida coast on Mon. The second front will reach from near Bermuda to eastern Cuba by late Tue. Fresh to strong northerly winds and building seas are expected behind the fronts. The wind speeds may reach gale-force behind the second front. $$ mt/mmt