000 AXNT20 KNHC 302231 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Oct 01 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 2215 UTC. ...SPECIAL FEATURES... Hurricane Sam is centered near 23.6N 60.9W at 30/2100 UTC or 560 nm SSE of Bermuda moving NW at 12 kt. Estimated minimum central pressure is 938 mb. Maximum sustained wind speed is 125 kt with gusts to 150 kt. Numerous moderate scattered strong convection is from 22N to 31N between 56W and 67W. Maximum significant wave height near the center is estimated at 45 ft. On the forecast track, the core of Sam will pass to the east of Bermuda early Saturday. Some fluctuations in intensity are expected during the next couple of days, but Sam is forecast to remain a major hurricane into Saturday, with more significant weakening anticipated later in the weekend. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT3.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT3.shtml for more details. Tropical Storm Victor is centered near 9.9N 30.0W at 30/2100 UTC or 510 nm SW of the Cabo Verde Islands moving WNW at 12 kt. Estimated minimum central pressure is 1003 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Numerous moderate convection is from 06N to 14N between 26W and 35W. Maximum significant wave height near the center is estimated to be near 15 ft. Gradual strengthening is forecast during the next day or so. However, a weakening trend is expected to begin over the weekend. Please also read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT5.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT5.shtml for more details. ...TROPICAL WAVES... A tropical wave extends from 06N to 15N with axis near 49W, moving W near 10 kt. Scattered showers are noted in the vicinity of the wave mainly near 11N49W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the W coast of Africa near 17N16W and continues to 14N22W. The ITCZ begins near 08N33W and extends to 06N54W. Aside from the convection associated with Victor and the tropical wave, scattered moderate convection is from 06N to 10N between 36W and 48W. GULF OF MEXICO... Microwave satellite imagery continue to show moisture inflow from the Caribbean to the western half of the gulf, which along with middle level divergent flow continue to support heavy showers and thunderstorms N of 20N and W of 93W. Model guidance suggests that this activity will continue through the weekend. Otherwise, a weak surface ridge covers the eastern half of the basin and provides mainly gentle to moderate E to SE flow basin-wide, except in the areas of convection where fresh winds are observed. Seas remains in the 1 to 3 ft range. For the forecast, a weak ridge of high pressure will persist north of the Gulf through Fri night, supporting tranquil conditions. Stronger higher pressure will build across the region by Sun, allowing winds and seas to increase over the SE Gulf over the weekend. A weak cold front should move across the Gulf on Mon and Tue, but with little enhancement of the winds and seas. CARIBBEAN SEA... An upper level trough extending a base to the south-central Caribbean continue to support showers and isolated tstms over E Cuba and portions of Hispaniola. Diffluent flow to the E of the upper trough support similar convective activity over the SE Caribbean waters. With a weak pressure gradient across the region, latest scatterometer data continue to depict gentle to moderate trades basin-wide. Seas are 3 ft or less across most of the Caribbean Sea, except in the northeast Caribbean passages, where swell from Hurricane Sam will peak through tonight. For the forecast, Hurricane Sam is well north-northeast of the Leeward Islands and will continue to generate swells over Atlantic waters from off the N Leeward Islands to north of the Mona Passage through Fri. Meanwhile, tranquil trades will prevail over the Caribbean through Fri. As high pressure builds in behind Hurricane Sam, winds are expected to become moderate to fresh across the central and E Caribbean and tropical N Atlantic by Sat through at least Tue. ATLANTIC OCEAN... Refer to the section above for details on Hurricane Sam and T.S. 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. For the forecast, Hurricane Sam will move to 25.6N 61.5W Fri morning, 28.5N 61.9W Fri afternoon, 31.3N 61.4W Sat morning, and then north of our waters by Sat afternoon. Sam will change little in intensity through Sat. Expect large swell from Sam to impact the area northeast of the Bahamas starting Fri and continuing through the weekend. Meanwhile, a weak pressure pattern will maintain quiescent conditions until tonight. A weak cold front will move from the Carolinas to the central Bahamas by Fri and dissipate by Sat. Stronger high pressure will build in to the area, which will bring moderate to occasionally fresh winds through Tue. $$ ERA