000 AXNT20 KNHC 101035 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Wed Nov 10 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 1030 UTC. ...SPECIAL FEATURES... Showers and thunderstorms associated with a powerful non-tropical low pressure system located more than 400 miles northeast of Bermuda. Recent satellite-derived wind data indicate that hurricane-force winds are occurring south of the center. However, the low is still interacting with a frontal boundary, and the system has not yet acquired enough tropical cyclone characteristics to be considered a subtropical storm. Additional development is still possible during the next day or two, and a subtropical storm could form during this time. Thereafter, the system is forecast to move over colder water and be absorbed by a larger non-tropical low. This system has a medium chance of development in the next 48 hours. Additional information on this system can be found in High Seas Forecasts issued by the National Weather Service which can be found under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php ....MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Sierra Leone near 08N13W to 07N17W, where it transitions to the ITCZ. The ITCZ then continues to 01N41W. Scattered moderate convection is noted about 90 nm on either side of the monsoon trough and ITCZ between 13W to 27W. GULF OF MEXICO... Surface ridging continues to dominate the Gulf of Mexico, with a 1023 mb surface high pressure centered over the Florida and Georgia border. Current observations across the basin continue to identify gentle to moderate winds over the W Gulf north of 25N and west of 90W. Seas ranged between 2 to 3 ft across the basin. For the forecast, a ridge prevails across the Gulf waters today providing gently to moderate E winds. Southerly return flow increases across the NW Gulf Wed night ahead of the next cold front forecast to enter the region Thu. The front will remain nearly stationary along the northern Gulf Fri. A reinforcing high pressure will push the front across the Gulf this weekend with fresh to strong northerly winds behind it. The front will reach the SE part of the basin by Sat night. CARIBBEAN SEA... A cold front over the western Atlantic crosses the Windward Passage and continues to near the western tip of Jamaica, where it transitions to a shearline and continues SW to 10N81W. Scattered tstorms are along the front in the Windward Passage and along the shearline. ASCAT data showed moderate to fresh N to NE winds north of the shearline. Theses winds will subside by the early morning hours today. The Pacific monsoon trough extends from northern Colombia W across Panama into the Eastern Pacific. Scattered moderate to isolated strong convection is noted along the boundary. Fresh to locally strong trades are also seen off the coast of NE Colombia and NW Venezuela. Gentle to moderate trades are noted elsewhere with 2 to 4 ft seas. For the forecast, a shearline extends from the Western tip of Jamaica to the SW Caribbean near 10N81W. Fresh to strong northerly winds will persist between the shearline and the coast of Nicaragua through the early in the morning. As high builds north of the Caribbean Sea, expect fresh to locally strong trade winds across the south-central Caribbean, and in the Gulf of Venezuela beginning tonight. These winds will likely persist through Fri. ATLANTIC OCEAN... A cold front extends from 31N5W to beyond 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 indicated higher seas W of the front with seas from 12 to 15 ft N of 27N. Further east, an upper-level low near 18N36W is inducing a broad area of scattered showers and thunderstorms from 12N to 24N and E of 24W over the Cabo Verde Islands to the coast of Africa. ASCAT data indicates moderate to fresh NE winds. A 1022 mb surface high pressure is center near 38N19W and extends southwestward to 22N57W. Gentle winds are near the ridge. Moderate trade winds prevail in the tropical latitudes, south of the ridge. For the forecast west of 65W, The cold front currently near 30N58W will continue moving E through Thu. Large seas follow the front covering the waters N of 21N. The front will remain over the SE waters while gradually weakening Thu. The seas will gradually subside over the next couple of days. The next cold front will move off NE Florida on Fri, then stall. Reinforcing high pressure will push the front across the region on Sat. 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