962 AXNT20 KNHC 022158 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 2130 UTC. ...SPECIAL FEATURES... Major Hurricane Sam is centered near 35.4N 58.2W at 02/2100 UTC or 380 nm ENE of Bermuda moving NE at 15 kt. Estimated minimum central pressure is 950 mb. Maximum sustained wind speed is 110 kt with gusts to 135 kt. Sam remains a well-organized hurricane as it moves farther away from Bermuda. Numerous moderate to strong convection extends outward from the center 180 nm in the N semicircle and 90 nm in the S semicircle. Scattered moderate convection exists elsewhere within 300 nm in the NE quadrant. Maximum significant wave height near the center is estimated at 45 ft, with seas 12 and greater extending outward as far as 330 nm from the center. A general track to the NE with an increase in forward speed is expected for the next few days, with a gradual turn more toward the N early next week. Slow weakening is forecast, but Sam could remain a major hurricane for the next day or so. After 36 hours, more significant weakening is anticipated. Sam is likely to transition to a powerful extratropical cyclone Tue. Please read the latest High Seas Forecast issued by the Ocean Prediction Center at website https://www.nhc.noaa.gov/text/MIAHSFAT1.shtml and the latest NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Newly-downgraded Tropical Depression Victor is centered near 13.7N 38.0W at 02/2100 UTC or 830 nm W of the Cabo Verde Islands moving NW at 12 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Numerous moderate to isolated strong convection is occurring in the NE quadrant between 60 and 300 nm from the center. There is no significant convection elsewhere near the center. Maximum significant wave height near the center is estimated to be near 15 ft, and the seas should gradually diminish during the next couple days. A general NW motion is expected to continue over the next few days. Strong wind shear and dry air will continue to lead to weakening of Victor, and the system is likely to degenerate into a remnant low tonight, and open into a low pressure trough by 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... A tropical wave has moved into the far eastern Caribbean, with its axis along 63W to the S of 19N, from the Virgin Islands to northern Venezuela. It is moving W at around 10 kt. The wave is embedded in a dry airmass that is suppressing the shower and thunderstorm activity, although some convection as developed this afternoon along the Venezuelan coast. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Senegal near 14N17W to 06N21W. The ITCZ then extends from 06N21W to 07N30W. The ITCZ resumes near 07N41W to 06N54W. Aside from convection associated with T.S. Victor, scattered moderate to isolated strong convection is observed within 150 nm of the monsoon trough and the ITCZ to the E of 25W. Scattered moderate convection is also noted within 120 nm north of the ITCZ between 42W and 57W. GULF OF MEXICO... The Gulf of Mexico is the SW periphery of a 1024 mb high pressure position over the SE United States. A surface trough is located in the NW Gulf within 60 nm of the coast of Texas and NE Mexico, especially from 30N94W to 24N97W. Scattered moderate convection is present within 150 nm to the east of the trough axis. A surface trough previously in the Bay of Campeche has dissipated this evening. Fresh E-SE winds are occurring in the SE Gulf, including the Florida Straits, while gentle to moderate winds prevail elsewhere. Seas of 3 to 5 ft are prevalent in the SE Gulf, with the highest seas occurring in the Florida Straits. Seas of 2-4 ft are present elsewhere in the Gulf. For the forecast, the weak ridge of high pressure will persist north of the Gulf through tonight, supporting tranquil conditions across the western half of the basin. Stronger higher pressure will build across the region on Sun, allowing winds and seas to increase over the SE Gulf. A weak cold front will move across the Gulf on Mon and Tue, with little enhancement of the winds and seas. CARIBBEAN SEA... An upper level trough over the W Atlantic reaches into the W Caribbean Sea, enhancing the development of scattered showers and isolated thunderstorms north-central basin. The most concentrated activity is noted N of 13N between 63W and 75W. Scattered moderate convection is also observed in the SW Caribbean, mainly within 150 nm north of Panama. Generally fresh trades are occurring over the central and eastern basin, with some localized strong winds occurring offshore NW Venezuela. Moderate winds prevail elsewhere, except for some light to gentle winds in the far SW Caribbean. Seas of 4-6 ft are found E of 75W and 2-4 ft elsewhere. For the forecast, high pressure will build north of the area through the weekend. This will bring an increase in trade winds and seas across the central and E Caribbean as well as the tropical N Atlantic later this weekend through the middle of next week. ATLANTIC OCEAN... Refer to the Special Features section above for details on Major Hurricane Sam and newly-downgraded 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. An expansive 1025 mb high pressure centered WSW of the Azores is dominating most of the basin. Aside from the influences of the aforementioned tropical cyclones, the only other feature of note is an upper level trough over the SW Atlantic. Divergence associated with this trough and abundant tropical moisture are inducing numerous moderate to isolated strong convection S of 25N between 65W and 72W. Fresh NE to E winds prevail W of 70W and S of 28N, including waters offshore the Florida Peninsula, Bahamas, and Turks and Caicos Islands. To the SE, a broad area of fresh NE to E trades is located S of 23N across the Atlantic. Outside of the two tropical cyclones, seas of 6 to 9 ft prevail across the basin. For the forecast, swells generated from Hurricane Sam, centered NE of the area, will impact the area west of 62W through the rest of the weekend. High pressure will build across the area in the wake of Sam, which will bring moderate to fresh winds Mon through mid week. $$ KONARIK