000 AXNT20 KNHC 302343 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sun Oct 31 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 1800 UTC surface analysis and satellite imagery through 2330 UTC. ...SPECIAL FEATURES... A strong low pressure system located several hundred miles south-southeast of Cape Race, Newfoundland, continues to produce some shower activity near and to the east of its center while moving southeastward at around 15 kt. The low appears to be gradually losing its frontal structure, and the system is likely to transition to a subtropical storm by early next week while it meanders over the central subtropical Atlantic. By the middle of next week, the system is expected to turn northward and move toward colder waters. For more information on this system, including gale warnings, see High Seas Forecasts issued by the National Weather Service. There is a medium chance of development for this system within the next 48 hours. Please read the latest Tropical Weather Outlook issued by the National Hurricane center at www.hurricanes.gov and the latest High Seas Forecast issued by the National Weather Service at ocean.weather.gov/shtml/NFDHSFAT1.php for more details. ...TROPICAL WAVES... An Atlantic tropical wave is along 32W from 18N southward and moving W at 5 kt. No significant shower activity is associated with the wave. ...MONSOON TROUGH/ITCZ... A monsoon trough exits the coast of The Gambia near 14N16W to 1008 mb low pressure near 09N24W to a second area low pressure near 07N31W. Scattered moderate and isolated strong convection is noted from 04N to 18N between the coast of Africa and 20W. The 1008 mb low along the monsoon trough near 09N24W is being monitored for potential tropical cyclone formation. Scattered moderate to isolated strong convection is noted 300 nm in the NE quadrant and scattered showers 180 nm in the SE quadrant. The associated shower and thunderstorm activity is showing signs of organization, and environmental conditions could support some development of this system during the next couple of days as it moves generally northwestward at 10 to 15 kt. The chance of formation within the next 48 hours is low. By the middle of next week, upper-level winds are forecast to become increasingly unfavorable for further development. GULF OF MEXICO... Isolated to scattered showers associated with a reinforcing surface trough are confined to the far eastern Gulf of Mexico, east of 85W. Otherwise, a 1017 mb surface high pressure is centered over the SW Gulf near 20N95W. The latest ASCAT pass shows fresh W to NW winds covering the eastern half of the Gulf of Mexico, locally strong in the SE Gulf. Light to gentle winds are in the SW Gulf near the high pressure. Wave heights in the SE Gulf, including the western Florida Straits and Yucatan Channel, are likely currently in the 8 to 12 ft range. Elsewhere, seas are 4 to 7 ft. For the forecast, the stationary front from central Cuba to the NE coast of Nicaragua will transition back to a cold front this evening and extend from eastern Cuba to the offshore waters of SE Nicaragua by Sun morning where the front will stall again. Moderate to fresh NW winds and seas of up to 10 ft are expected over the far NW Caribbean through this evening. Moderate to fresh N to NE winds will continue between the front and adjacent waters of E Honduras and Nicaragua. Elsewhere, a weak pressure gradient ahead of the front will support mainly gentle to moderate trade winds across the basin through the middle of next week, with locally fresh winds in the Gulf of Venezuela through early this evening. CARIBBEAN SEA... A stationary front extends from central Cuba near 21N78W to eastern Nicaragua near 12N83W. A recent ASCAT pass shows fresh NW winds covering the NW Caribbean, west of the front. Seas are 5 to 8 ft in this area, except 9 to 12 ft in the Yucatan Channel. Scattered moderate showers and isolated thunderstorms are along and about 60 nm se of the front. The eastern end of the eastern Pacific monsoon trough extends from 12N72W N of Colombia to a 1009 mb low pres near 12N77W, then continues westward to the coast of Costa Rica/Nicaragua border. Scattered moderate and isolated strong convection is noted south of 14N between 65W- 85W. To the east, moderate trades prevail over the eastern and central Caribbean, except for fresh from 12N-17N between 68W- 75W. Seas are 4-7 ft in the central Caribbean, and 2-4 ft in the eastern and SW portions of the basin. For the forecast, the stationary front will transition back to a cold front this evening and extend from eastern Cuba to the offshore waters of SE Nicaragua by Sun morning where the front will stall again. Moderate to fresh NW winds and seas of up to 10 ft are expected over the far NW Caribbean through this evening. Moderate to fresh N to NE winds will continue between the front and adjacent waters of E Honduras and Nicaragua. Elsewhere, a weak pressure gradient ahead of the front will support mainly gentle to moderate trade winds across the basin through the middle of next week, with locally fresh winds in the Gulf of Venezuela through early this evening. ATLANTIC OCEAN... West of 65W: A stationary front extends from 31N71W to the central Bahamas near 25N76W to central Cuba near 22N78W. Scattered moderate isolated strong showers and thunderstorms are firing within 60 nm east of the front. A recent ASCAT pass shows fresh to strong S-SW winds ahead of the front to 69W with fresh to strong SW to W winds west of the front, through the NW Bahamas and Florida Straits as well as east of Florida. Seas are 7 to 11 ft to the north and northeast of the Bahamas and 5 to 7 ft farther south, closer to Puerto Rico. Further east, the tail end of a stationary front enters the forecast area near 31N44W to 27N52W. Scattered showers are noted mainly from 25N to 31N between 38W to 44W. Two areas of high pressure are present between this boundary with a 1019 mb high near 28N23W andto the west a 1015 mb high near 27N62W. Light to gentle winds are near the high pressure ridges with a fresh NE trades noted from 12N to 22N and E of 34, near the coast of Africa. In the forecast, the cold front will move slowly east and reach from Bermuda to eastern Cuba Sun morning. Fresh to strong winds are expected on both sides of the front through tonight, mainly north of 25N. Seas of 8 ft or greater will continue to prevail north of 26N east of 78W, as well as in the Florida Straits, lingering through Sun before decaying. The front will weaken as it stretches from 30N65W to the Turks and Caicos Islands Mon morning with gentle to locally moderate NE flow then prevailing across the southern Bahamas and the Great Bahama Bank into mid- week. The Cumbre Vieja volcano, on the island of La Palma in the Canary Islands, has been erupting since 19 September 2021. Recently, there has been an increase in volcanic ash emission, with medium to high ash concentration spreading up to 30 to 35 nm west of the volcano. High volcanic ash concentration remains in the vicinity of the volcano. Marine and aviation interests should monitor this ongoing situation by reading the Volcanic Ash Advisory issued by Meteo-France at website http://vaac.meteo.fr/volcanoes/la-palma/. $$ Torres