361 AXNT20 KNHC 091806 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Tue Nov 09 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 extends from the coast of Liberia near 07N11W to 05N18W, where it transitions to the ITCZ per latest scatterometer data. The ITCZ then continues to 02N41W to 01N44W. A surface trough is analyzed north of the ITCZ from 10N30W to 08N36W. Scattered moderate convection is seen from 01N to 06N between 10W-18W and within 60 nm north of the trough between 15W-18W. GULF OF MEXICO... Surface ridging continues to dominate the Gulf of Mexico, with a 1028 mb surface high pressure centered over eastern Mississippi. Latest ASCAT data shows gentle winds over the western Gulf north of 20N and west of 90W, while gentle to moderate northeast to east winds are elsewhere. Seas are in the 2-4 ft range throughout the basin. Isolated showers are possible over the far NW Gulf. For the forecast, a ridge will continue to dominate the Gulf waters through Wed promoting gentle to moderate NE to E winds. Southerly return flow will set-up across the NW Gulf on Wed night ahead of the next cold front forecast to enter the region on Thu. The front will remain nearly stationary over the northern Gulf on Fri. Reinforcing high pressure will push the front across the Gulf on Sat, reaching the southeastern part of the Gulf by Sat evening. CARIBBEAN SEA... A cold front over the western Atlantic stretches southwestward to the north coast of Hispaniola, where it transitions to a stationary front to central Jamaica and becomes a weakening stationary front to just east of the coast of Nicaragua at 12N84W. Latest ASCAT depicts fresh north winds behind the front over most of the northwestern Caribbean, except for locally strong N winds off the southern coast of Nicaragua, from 11N to 13N between 82W- 84W. Seas with these winds are in the 4-6 ft range. The eastern segment of the eastern Pacific monsoon trough is over northwestern Colombia from near 11N74W to low pressure of 1009 near 09N77W and southwest from there to the over the Pacific area south of Panama. Low-level wind convergence near the southern part of the weakening stationary front is helping to enhance scattered moderate convection that is occurring south of 13N and west of 76W to along the coast of Panama and southern Nicaragua. Gentle to moderate trades are noted elsewhere along with seas of about 2 to 4 ft seas. For the forecast, the aforementioned weakening stationary will dissipate by late this afternoon. Fresh northerly winds will persist within about 60 NM of the coast of Nicaragua through tonight. As high builds north of the Caribbean Sea, expect for increasing trades across the south-central Caribbean, and in the Gulf of Venezuela beginning tonight. ATLANTIC OCEAN... A cold front extends from near 31N59W to 25N65W and to the north coast of Hispaniola, where it transitions to a stationary into the the western Caribbean Sea. A secondary and more pronounced cold front extends from a 998 mb storm center that is north of the area near 35N64W southwestward to 31N65W and to 26N73W. The latest ASCAT pass indicates fresh southwest to west winds north of 28N between 61W-65W and similar moderate to fresh northwest to north winds north of 28N between 66W-70W. Seas of 9-13 ft in north to northeast swell are over these waters per latest altimeter data. For the forecast, the first cold front will become stationary tonight as the second cold front merges with it. Large seas follow the front covering the waters north of 22N. These seas will gradually subside from east to west over the next couple of days. The front will remain over the southeastern waters while gradually weakening. The next cold front will move off the northeast Florida on Fri, then stall. Reinforcing high pressure will push the front to move 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/. $$ Aguirre