000 AXNT20 KNHC 110959 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Thu Nov 11 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 0600 UTC surface analysis and satellite imagery through 1130 UTC. ...SPECIAL FEATURES... A storm-force non-tropical area of low pressure located about 900 miles east-northeast of Bermuda continues to produce a large area of showers that extend from the center northward along an associated frontal boundary. This system is moving northeastward, and it could still become a short-lived subtropical storm before it reaches cooler waters by this evening. By this weekend, the system is expected to be absorbed by a larger non-tropical low. There is a medium chance for development in the next 48 hours. Additional information on this system, including hurricane-force wind warnings, can be found in High Seas forecasts issued by the National Weather Service. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast southern coast of Guinea near 09N13W to 08N14W, where it transitions to the ITCZ to 04n29w to 03n42w. Scattered moderate isolated strong convection is noted on either side of the boundaries from 01N to 12N and E of 27W, and scattered showers north of the ITCZ from 06n to 10n between 30W to 40W. GULF OF MEXICO... Broad surface anticyclonic wind flow spans the Gulf of Mexico. A surface ridge extends from the northeastern corner of the area, to the southwestern corner of the Gulf of Mexico. On the forecast, gentle to moderate return flow will prevail through today. A cold front will move into the northern Gulf coastal waters tonight, stalling into Fri. Reinforcing high pressure will push the front across the Gulf Fri night through Sat night, moving southeast of the basin early Sun. High pressure will build in the wake of the front, with winds in the southeast Gulf increasing to fresh to strong early next week. CARIBBEAN SEA... A weakening cold front over the western Atlantic crosses the Windward Passage and transitions to a shear line towards the southwest, near the coast of Nicaragua. A robust shortwave trough in the upper levels is noted over Honduras and Nicaragua enhancing difluence over the western Caribbean where the scattered moderate convection is noted this morning ahead of the shearline. Moderate to fresh winds are noted north of the shearline. The scattered moderate convection is noted along and north of the shearline to the NW coast of Cuba. Seas of 3 to 5 ft are occurring across the basin, except 2 to 4 feet noted in the southwest Caribbean. The Pacific monsoon trough extends from northern Colombia westward and crosses Panama into the Eastern Pacific Ocean. Scattered showers are noted along the boundary and along the coast of Nicaragua and Costa Rica. For the forecast, the tail end of a stalling front extending from near the Windward Passage to offshore of Nicaragua will gradually dissipate through the end of the week. Moderate to fresh winds in the NW Caribbean will diminish to gentle by the end of the week. Moderate to fresh winds will prevail across the remainder of the basin, pulsing to fresh to strong in the south- central Caribbean tonight and again Fri night. A new cold front is forecast to move into the NW Caribbean by the end of the upcoming weekend. ATLANTIC OCEAN... A cold front extends from 31N48W to 22N65W, where the boundary transitions to a weakening front into the Windward Passage. Isolated moderate showers are found along the boundary. Latest ASCAT data indicated strong winds remain north of the forecast area. However, altimeter data continues to indicate higher seas W of the front with seas from 8 to 13 ft from the southern Bahamas north to 31N. and E of 74W. Further east, scattered showers and thunderstorms are noted near a surface trough from 31N32W to 21N31W. ASCAT data indicates moderate to fresh NE winds. A 1018 mb surface high pressure is center near 28N40W and extends southwestward to 19N51W. Gentle winds are near the ridge. Moderate trade winds prevail in the tropical latitudes, south of the ridge. For the forecast west of 65W, a tail end of a cold front extending from 30N48W to the Windward Passage will continue moving southeast through Thu, stalling and dissipating along 22N by Fri. Large seas following the front will gradually decay through the end of the week. The western remnants of the front in the form of a trough will linger between 70W and 77W into the early part of the weekend, with weak low pressure possibly developing along it before moving north of the area late Sat. The next cold front will move off NE Florida by Fri night, then stall. Reinforcing high pressure will slowly push the front across the region during the weekend into early next week. 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 latest Volcanic Ash Advisory issued by Meteo-France at website http://vaac.meteo.fr/volcanoes/la-palma/. $$ Torres