000 AXNT20 KNHC 122254 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sat Sep 12 2020 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2230 UTC. ...SPECIAL FEATURES... Tropical Storm Sally is centered near 25.7N 81.9W at 12/2100 UTC or 30 nm SSW of Naples Florida moving W at 6 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Scattered moderate isolated strong convection is noted within 180 nm SE semicircle. A west- northwestward or northwestward motion is expected during the next couple of days. The center of Sally is forecast to move over the southeastern and eastern Gulf of Mexico tonight and Sun, and then move over the north-central Gulf of Mexico Sun night and Mon. Strengthening is expected over the next couple of days, and Sally is forecast to become a hurricane on Mon. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT4.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT4.shtml for more details. Tropical Storm Paulette is centered near 28.4N 58.5W at 12/2100 UTC or 400 nm SE of Bermuda moving NW at 13 kt. Estimated minimum central pressure is 987 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Seas 12 ft or greater are within 240 nm NE quadrant, 120 nm SE quadrant, 180 nm SW quadrant, and 210 nm NW quadrant with peak seas to 28 ft. Scattered moderate isolated strong convection is noted within 150 nm NW quadrant. A northwestward or west-northwestward motion is expected through Sun night, followed by a turn toward the north with a decrease in forward speed on Mon, and a northeastward motion Mon night and Tue. The center of Paulette will move near or over Bermuda Mon morning. Strengthening is forecast, and Paulette is expected to become a hurricane tonight. Paulette is expected to be a dangerous hurricane when it is near Bermuda Sun night and Mon. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT2.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT2.shtml for more details. Tropical Depression Rene is centered near 24.3N 45.6W at 12/2100 UTC or 1040 nm ENE of the Northern Leeward Islands moving NW at 12 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Seas 12 ft or greater are within 30 nm NW quadrant with peak seas to 13 ft. Isolated weak convection is noted within 150 nm NW quadrant. A slower northwestward motion is expected by Sun, and a slow westward motion is forecast by Sun night. On Mon and Tue, the system is forecast to turn west-southwestward. Some gradual weakening is possible over the next few days. 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 Depression Twenty is centered near 11.4N 33.5W at 12/2100 UTC or 1760 nm E of the Northern Leeward Islands moving WNW at 8 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate convection is noted within 240 nm W semicircle. A west-northwestward motion is expected to continue for the next few days with a slight increase in forward speed early next week. Slow strengthening is expected over the next day or so, and the depression is forecast to become a tropical storm by Sun night. A faster rate of strengthening is possible early next week. Please 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. Showers and thunderstorms located near the Cabo Verde Islands are associated with a broad area of low pressure that has developed along a tropical wave near 24W. Environmental conditions support some additional development during the next few days, and a tropical depression could form over the far eastern tropical Atlantic early next week while the system moves slowly west- northwestward. By mid-week, upper-level winds could become less conducive for development. This system has a medium chance of tropical cyclone formation during the next 48 hours. ...TROPICAL WAVES... An eastern Atlantic tropical wave axis is along 24W, moving W at 10-15 kt. Scattered moderate isolated strong convection is noted from 15N to 18N between 24W and 28W. Please see the Special Features section above for more details. A tropical wave axis associated with Tropical Depression Twenty is along 33.5W, moving W at 10-15 kt. Please see the Special Features section above for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Mauritania near 18N16W to 12N30W to 10N43W. Besides the convection described above, isolated moderate convection is noted within 240 nm of the monsoon trough W of 24W. GULF OF MEXICO... Please see the Special Features section above for more details on Tropical Storm Sally. A dissipating stationary front is analyzed across the western Gulf this evening, with some isolated showers and thunderstorms noted near the boundary. Earlier scatterometer data showed moderate to fresh NW winds in the SW Gulf near the coast of Veracruz. Moderate to fresh easterly winds are occurring over the NE Gulf. Seas are 4-6 ft in this region based on recent buoy observations. Elsewhere, a trough extends across the north-central Gulf from 28N94W to 24N89W. Some slow development of this system is possible while it moves westward and then southwestward over the northern and western Gulf through the middle of next week. This system has a low chance of tropical cyclone formation. Tropical Storm Sally will move to 26.4N 83.4W Sun morning, 27.3N 85.3W Sun afternoon, 28.0N 86.9W Mon morning, then strengthen to a hurricane near 28.5N 88.1W Mon afternoon. Hurricane Sally will be near 29.0N 89.0W Tue morning and 29.7N 89.3W Tue afternoon. Sally will weaken to a tropical storm while moving inland over Louisiana and Mississippi Wed afternoon. Elsewhere, a surface trough over the north central Gulf will move west and southwest over the northern and western Gulf of Mexico through the middle of next week. This trough has a low chance of tropical formation. CARIBBEAN SEA... A weak pressure gradient over the basin is supporting light to gentle winds across the region, with some moderate trades noted near the northern coast of Colombia. Swell from distant Tropical Storm Paulette continues impacting the Atlantic and Caribbean passages. Otherwise, seas are 2-4 ft in the south-central waters, and 3 ft or less elsewhere. Tropical Storm Paulette will continue to move north away from the area, but large swell associated with Paulette will affect the Atlantic and Caribbean Passages this weekend. Rene has weakened to a tropical depression this morning well east of the area. Tropical Depression Rene is not expected to strengthen, but could approach areas north and east of the Leeward Islands toward the middle of next week. ATLANTIC OCEAN... Please see the Special Features section above for more details on Tropical Storm Paulette, Tropical Depression Rene, and Tropical Depression Twenty. Outside of the tropical systems, light to gentle winds prevail across the Atlantic waters S of 20N and W of 35W. Seas in this area are generally 4-7 ft. Some isolated showers and thunderstorms are ongoing east of the Windward Islands, from 11N to 14N between 55W and 60W. Elsewhere, swell associated with Paulette has spread across much of the region W of 50W, with seas 8 ft or greater in the offshore waters as far as 70W. Tropical Storm Paulette will strengthen to a hurricane near 29.2N 60.4W Sun morning and move to 30.3N 62.8W Sun afternoon. Hurricane Paulette should be near31.8N 64.6W Mon morning, 33.5N 64.9W Mon afternoon, 35.3N 63.2W Tue morning, and 37.0N 59.8W Tue afternoon. Large swell associated with Paulette will spread westward across the offshore waters and continue to build seas this weekend into early next week. Tropical Depression Rene is not expected to strengthen, but could approach areas north and east of the Leeward Islands toward the middle of next week. Newly formed Tropical Depression Twenty may approach the Tropical N Atlantic offshore waters toward the end of next week. $$ B Reinhart