000 AXNT20 KNHC 210407 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 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 0000 UTC surface analysis and satellite imagery through 0330 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of Guinea near 11N15W to 09N16W to 06N20W. The ITCZ continues from 06N20W to 04N30W to 03N48W. Scattered strong convection is noted from 03N-08N between 10W-15W. Scattered moderate convection is occurring from 01N-10N between 21W-35W. GULF OF MEXICO... A surface trough is in the SW Gulf from 22.5N 97W to 18.5N 93.5W. Scattered showers and isolated tstorms are occurring south of a line from Marco Island Florida to 21N96W. Drier weather prevails over the northern Gulf. Fresh to locally strong ENE winds are prevalent over the northeast Gulf of Mexico. Buoy 42036 near 28.5N 84.5W is recording 25 kt E winds and seas of 5 ft. Moderate SE winds prevail in the western Gulf. Most of the basin is covered by seas of 4 to 6 ft, except for 2 to 4 ft in the NW Gulf. For the forecast, high pressure centered over the Carolinas is building across the region. A strong cold front will move into the basin by early Mon. Fresh to strong northerly winds are expected behind the front, mainly over the eastern Gulf, Mon through Tue night. High pressure is forecast to build in behind the front by the middle of the upcoming week. CARIBBEAN SEA... Mid to upper-level anti-cyclonic flow covers the Caribbean basin. This is leading to relatively dry weather over the eastern and central Caribbean. Scattered showers and isolated tstorms are noted near the Yucatan Channel and also in the SW Caribbean offshore of Costa Rica and Nicaragua. Fresh trade winds are occurring across the central Caribbean with seas of 4 to 6 ft. Mainly moderate winds prevail in the eastern and northwest Caribbean with 2 to 4 ft seas. The exception is the Yucatan Channel, where seas of 5 to 7 ft are likely occurring. For the forecast, mainly gentle to moderate trades will prevail across much of the Caribbean Sea through tonight. A cold front will reach the Yucatan Channel by Mon evening, and extend from eastern Cuba to the Gulf of Honduras by Tue evening. Fresh to locally strong winds and building seas are expected behind the front across the western Caribbean, the Windward Passage and Mona Passage through the middle of the upcoming week. ATLANTIC OCEAN... A cold front stretches from 31N63W to 29N69W, where it transitions to a stationary front that extends WSW to Ft. Lauderdale Florida. Scattered showers prevail along and within 330 nm south of the front. The latest ASCAT pass shows strong to locally near gale force NE to ENE winds prevailing within 180 nm north of the front. Seas of 9 to 12 ft are likely occurring in this area. At NOAA buoy 41010 near 28.9N 78.5W, ENE winds of 25 kt and seas of 10 ft were measured at 21/0200 UTC. Farther east, a 1021 mb high pressure is analyzed near 33N47W. A cold front stretches from 31N27W to 27N29W to 24N36W. A trough is ahead of this front, extending from 31N23W to 26N25W to 22N31W. The latest ASCAT satellite wind data show near gale force S winds of 30-33 kt within 120 nm east of the surface trough, north of 29N. Fresh NW winds are west of the cold front, north of 28N. Seas of 8 to 11 ft prevail north of 27N between 20W-45W. Gentle to moderate winds cover most of the area from 02N-25N between Africa and 65W, with 4 to 7 ft seas. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Medium ash concentration is in the vicinity of the volcano, while low concentration is elsewhere. 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 65W, strong NE to E winds will continue north of the stationary front today due to a tight pressure gradient from strong high pressure offshore the southeastern United States. This is expected to lead to hazardous marine conditions through late today, with large swells possibly lingering into Mon. The stationary front will remain across the northern forecast waters through tonight, before lifting north ahead of a strong cold front that will move off the northeast Florida coast on Mon. Strong to near gale force N winds are expected across the area on Tue behind the cold front, with building seas. Winds could reach gale force Tue behind the front, several hundred nm to the east of the northern Florida. $$ Hagen