732 AXNT20 KNHC 032159 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sun Oct 3 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 2100 UTC. ...SPECIAL FEATURES... Hurricane Sam is centered near 38.6N 52.8W at 03/2100 UTC or 490 nm S of Cape Race Newfoundland moving ENE at 14 kt. Estimated minimum central pressure is 964 mb. Maximum sustained wind speed is 85 kt with gusts to 105 kt. Sam remains a well-organized Category 2 hurricane as it moves further into the mid-latitudes. Numerous moderate and isolated strong convection extends outward from the center 120 nm. Maximum significant wave height is estimated at 41 ft, with seas 12 ft and greater extending outward as far as 400 nm from the center. A general track to the NE at a faster forward speed is expected into Tue, before Sam slows and begins to merge with a trough. Gradual weakening is forecast during the period, but the wind field associated with Sam will continue to expand, and it is likely to remain a hurricane until it transitions into a powerful post-tropical cyclone Tue. Please read the latest High Seas Forecast issued by the Ocean Prediction Center at website https://ocean.weather.gov/mobile/mobile_product.php?id=NFDHSFAT1 and the latest NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Tropical Depression Victor is centered near 17.1N 41.3W at 03/2100 UTC or 990 nm W of the Cabo Verde Islands moving NW at 11 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Strong wind shear continues to displace the convection to the E semicircle. Scattered moderate to isolated strong convection extends outward from the center 300 nm in the E semicircle. Maximum significant wave height near the center is estimated to be near 14 ft and the seas are expected to gradually decrease over the next few days. A W to NW motion is expected over the next couple of days. Weakening is expected and Victor will become a remnant low Mon, then dissipate early Tue. Please read the latest High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... An Atlantic tropical wave has its axis along 22W, south from the Cabo Verde Islands, moving W at 10 to 15 kt. No deep convection is noted in association with this wave. A Caribbean tropical wave has its axis along 70W, south of 20N, extending from Dominican Republic to NW Venezuela, and is moving W at 10 to 15 kt. Scattered moderate to strong convection is noted with and ahead of the wave N of 14N and between 67W and 77W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Senegal near 15N17W to 05N30W. The ITCZ is from 05N30W to 10N37W. The ITCZ then resumes from 09N44W to the coast of Guyana near 07N58W. Scattered moderate to isolated strong convection is observed within 120 nm of either side of the monsoon trough and ITCZ between 19W and 37W. GULF OF MEXICO... A dome of high pressure positioned between the Outer Banks and Bermuda extends SW to the Gulf of Mexico, allowing for a weak pressure gradient across the basin. Moderate E winds are noted in the SE Gulf and offshore the Yucatan Peninsula, while weaker winds prevail elsewhere. A surface trough just offshore the Texas and Mexico coasts remains stationary, but associated convection has diminished today. Another trough previously over the Bay of Campeche has dissipated. Seas are 2 to 4 ft in the Gulf, with the highest seas occurring in the E Gulf waters. For the forecast, a weak ridge of high pressure north of the Gulf along 32N will move eastward through Tue, supporting tranquil conditions across all but the southeast sections of the basin. A weak cold front will move across the Gulf on Mon and Tue, with little enhancement of the winds and seas. CARIBBEAN SEA... See Tropical Waves section above for details on convection associated with a tropical wave over the central Caribbean. A mid- level trough extending from the central Bahamas to eastern Cuba to near Jamaica is leading to scattered showers and thunderstorms over Haiti, Jamaica, eastern Cuba, and adjacent waters. Convection previously associated with the eastern extension of the eastern Pacific monsoon trough has diminished this afternoon. Fresh to locally strong trades encompass the eastern and central Caribbean Sea, with generally moderate trades elsewhere in the basin. Seas of 5-7 ft are present in the central and E Caribbean Sea, while 3-5 ft seas are noted in the W and SW Caribbean. For the forecast, high pressure will build north of the area. This will increase winds and seas across the central Caribbean Mon and Tue. Moderate N to NE swell will affect the tropical Atlc waters through Tue. ATLANTIC OCEAN... Refer to the Special Features section above for details on Hurricane Sam and Tropical Depression Victor. The Cumbre Vieja volcano on the island of La Palma in the Canary Islands near 28.6N 17.8W has been erupting since September 19th. High concentration of volcanic ash is found near the volcano. Marine and aviation interests should monitor this ongoing situation by reading the latest Volcanic Ash Advisory issued by Meteo-France at http://vaac.meteo.fr/volcanoes/la-palma/ for details. A deep layer trough extends from 26N67W through the central Bahamas and southward into eastern Cuba. This trough combining with rich tropical moisture is resulting in a large area of showers and thunderstorms across eastern Cuba, Haiti, the eastern Bahamas, and adjacent waters. Fresh easterlies are occurring to the east of this trough, W of 67W. A surface trough, extending S from Hurricane Sam, stretches from 31N55W to 26N61W. Numerous moderate convection is noted E of this trough axis to around 52W. Some fresh SSW winds are occurring in the vicinity of this trough and associated convection. A broad 1026 mb ridge located near the Azores dominates most of the NE Atlantic. The pressure gradient between the ridge and lower pressures in South America results in generally fresh trades S of 22N between 45W and the Lesser Antilles. The highest winds are occurring in the waters near the Windward Islands. A similar pressure gradient occurs in the NE Atlantic between the ridge and lower pressures found in NW Africa, producing fresh to locally strong NE winds E of 28W and N of 20N, with the strongest winds occurring in the waters surrounding the Canary Islands and near the coast of NW Africa. Mainly moderate winds are present in the rest of the basin. Outside of the influence of Hurricane Sam and Tropical Depression Victor, seas of 5-8 ft prevail in the tropical Atlantic. For the forecast, swells generated from Hurricane Sam, centered well NE of the area, will impact the area waters through Mon. High pressure along the mid Atlc coast will drift slowly eastward through mid week. This will produce moderate to fresh trade winds south of 23N and east of the Bahamas through Tue before spreading into the southeast Bahamas. Active weather is expected to develop across the waters E of 75W and NE the Bahamas Mon night through Tue as a surface trough becomes better defined and drifts NW. $$ KONARIK