000 AXNT20 KNHC 211800 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sun Nov 21 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 1745 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains of Sierra Leone near 08N13W, to 07N14W. The ITCZ continues from 07N14W, to 06N25W, 05N30W, 07N36W, and 08N41W. Precipitation: widely scattered moderate to isolated strong is from 08N southward from 43W eastward. Broken to overcast multilayered clouds, and isolated moderate, are elsewhere, from 15N southward between 43W and 60W. GULF OF MEXICO... A surface ridge passes through central Alabama, to the coastal waters of SW Louisiana, to the coastal plains of east central Mexico. Fresh to strong winds are from 90W eastward. Moderate to fresh winds are elsewhere. The sea heights range from 5 feet to 7 feet from Cuba to the Tampa Florida area. The sea heights range from 2 feet to 4 feet elsewhere. A ridge will dominate the Gulf waters today. The next cold front will enter the basin by early Mon and move quickly SE, exiting the Gulf region by Mon evening. Fresh to strong northerly wind will be expected behind the front, mainly in the eastern Gulf late Mon into Tue. High pressure is forecast to build into the area behind the front. Fresh southerly return flow will set up across the NW Gulf by the middle of the week ahead of the next cold front forecast to reach the Gulf waters by Thu night. CARIBBEAN SEA... Broad upper level anticyclonic wind flow covers the entire Caribbean Sea. Comparatively drier air in subsidence is apparent in water vapor imagery from 76W eastward. Precipitation: widely scattered moderate to isolated strong is from 12N northward from the Windward Passage westward. The monsoon trough is along 10N from northern Colombia at 74W, southwestward beyond Costa Rica. Precipitation: widely scattered moderate to isolated strong is within 120 nm to the north of the monsoon trough. 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. Moderate to fresh winds cover the Caribbean Sea from the Windward Passage eastward, and from Jamaica southward and between Jamaica and Central America. Gentle to moderate wind speeds are elsewhere. The sea heights range from 2 feet to 4 feet from 79W westward,. The sea heights range from 5 feet to 6 feet between 70W and 80W. The sea heights range from 2 feet to 4 feet elsewhere. Mainly gentle to moderate trades will prevail across much of the Caribbean Sea through Mon. 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: in the western Caribbean Sea, the Windward Passage and Mona Passage likely through Thu, as high pressure builds N of the area in the wake of the front. ATLANTIC OCEAN... A dissipating stationary front is along 31N59W, to 28N74W. A shear line continues from 28N74W to the coast of Florida near 27N80W, and just to the east of Lake Okeechobee in the southern part of Florida. Precipitation: widely scattered moderate to isolated strong is within 600 nm to the southeast of the cold front. The sea heights range from 8 feet to 11 feet from 27N northward between 60W and 70W. Fresh to strong winds are from 27N northward from 60W westward. Moderate or slower winds are elsewhere from 60W westward. Upper level cyclonic wind flow covers the Atlantic Ocean from 15N northward from 40W eastward. The upper level trough that is in this area is supporting a cold front, that is from 700 nm to 1200 nm to the west of Africa from 20N northward from 40W eastward. A first surface trough is about 225 nm to 350 nm to the SSE of the cold front. A post-frontal trough is about 150 nm to 200 nm to the NW and N of the cold front. Precipitation: broken to overcast multilayered clouds and isolated moderate are from 10N to 15N between 40W and 60W; from 20N northward between Africa and the first surface trough; and from 20N northward between the cold front and 65W. The sea heights range from 8 feet to 13 feet, from 22N northward between 30W and 40W. The sea heights range from 3 feet to 4 feet from the Cabo Verde Islands northward between Africa and the first surface trough. The sea heights range from 4 feet to 6 feet, elsewhere from 20N southward from 60W eastward. Fresh to strong winds are from 27N northward between 15W and 43W. The wind speeds are moderate or slower, elsewhere from 20N southward from 60W eastward. 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 weakening stationary front, extending 31N59W to near West Palm Beach in Florida, will remain in the northern forecast waters through tonight, before moving northward, ahead of a strong cold front that will move off the northeast Florida coast on Mon. The next cold front will reach from near Bermuda to eastern Cuba late on Tue. Fresh to strong winds and building seas are expected on either side of the front beginning on Tue. It is likely for the wind speeds to reach gale force N of 30N, and just W of the front, by Tue evening. $$ mt/mmt