000 AXNT20 KNHC 162334 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Wed Sep 16 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 2310 UTC. ...SPECIAL FEATURES... Recently downgraded Tropical Storm Sally at 16/2100 UTC is centered near 31.2N 86.8W, or 48 nm NNE of Pensacola, Florida and 74 nm W of Dolphin, Alabama, moving NE at 6 kt. Minimum central pressure is 990 mb. Maximum sustained winds are 50 kt with gusts to 60 kt. Peak seas are currently 16 ft with 12 ft seas extending 120 nm in the SE quadrant and 75 nm in the SW quadrant. Scattered moderate to strong convection extends 100 nm in the eastern semicircle. Sally will begin moving northeastward at a slightly faster forward speed tonight through Thursday night. On the forecast track, the center of Sally will move across southeastern Alabama tonight, over central Georgia on Thursday, and move over South Carolina Thursday night. Additional weakening is expected as the center moves farther inland tonight, and Sally is forecast to become a tropical depression tonight or Thursday morning. Please read the latest NHC Public Advisory at: https://www.nhc.noaa.gov/text/MIATCPAT4.shtml, and the Forecast/Advisory at: https://www.nhc.noaa.gov/text/MIATCMAT4.shtml, for more details. The center of Hurricane Teddy at 16/2100 UTC is near 17.5N 50.8W, or 617 nm ENE of the Lesser Antilles, moving W at 11 kt. Maximum sustained winds are 85 kt with gusts to 105 kt. Minimum central pressure is 973 mb. Peak seas are currently 30 ft and the 12 ft seas extend 300 nm in the NW and SE quadrants and 330 nm in the NE quadrant and 270 nm in the SW quadrant. Scattered moderate to strong convection is within 170 nm of the W semicircle and 150 nm in the E semicircle. Teddy will continue to move northwest for the next few days. Additional strengthening is expected over the next day or so, and Teddy is expected become a major hurricane during that time. Please read the latest NHC Public Advisory at: https://www.nhc.noaa.gov/text/MIATCPAT5.shtml, and the Forecast/ Advisory at: https://www.nhc.noaa.gov/text/MIATCMAT5.shtml, for more details. The center of Tropical Storm Vicky at 16/2100 UTC is near 21.5N 35.7W, or 743 nm WNW of the Cabo Verde Islands, moving W at 8 kt. Maximum sustained winds are 35 kt with gusts to 45 kt. Minimum central pressure is 1008 mb. Peak seas are currently 15 ft with the 12 ft seas extending 120 nm in the N semicircle, 30 nm in the SE quadrant, and 75 nm in the SW quadrant. Scattered moderate convection extends 180 nm in the NE quadrant. Vicky is expected to continue a westward motion through late Thursday. A west- southwestward motion is forecast to begin by Friday and continue through dissipation. Additional weakening is forecast, and Vicky is expected to become a tropical depression Thursday, weaken to a remnant low on Friday, and dissipate Saturday. Please read the latest NHC Public Advisory at : https://www.nhc.noaa.gov/text/MIATCPAT1.shtml, and the Forecast/Advisory at: https://www.nhc.noaa.gov/text/MIATCMAT1.shtml, for more details. A tropical wave has an axis along 25W south of 15N, and is moving westward at 10 knots. A 1010 mb low is along the tropical wave near 10N25W. Scattered moderate isolated strong convection is from 09N-13N between 25W- 28W. Environmental conditions are conducive for development of this system and a tropical depression is likely to form during the next few days while the system moves generally westward at 10 to 15 mph. There is a medium chance of tropical cyclone formation within the next 48 hours. Please read the latest Tropical Weather Outlook at: www.nhc.noaa.gov/gtwo.php for more details. Showers and thunderstorms associated with a 1009 mb low in the southwestern Gulf of Mexico near 21N95W will gradually continue to become better organized. Upper- level winds are forecast to gradually become more conducive for further development, and a tropical depression is likely to form late this week or over the weekend while the low meanders over the southern Gulf of Mexico for the next several days. There is a medium chance of tropical cyclone formation within the next 48 hours. Please read the latest Tropical Weather Outlook at: www.nhc.noaa.gov/gtwo.php for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough axis remains over inland Africa. The monsoon trough and the ITCZ have been disrupted by the activity of the current tropical cyclones. GULF OF MEXICO... Outside of convection associated with the low in the SW Gulf and convection from T.S. Sally, conditions remain quiet for the rest of the basin. Gentle to moderate winds are in the SE Gulf, light to gentle winds in the NW Gulf, and moderate to fresh winds W of the low in the SW Gulf. Seas 3-6 ft. Recently downgrade Tropical Storm Sally will continue inland and weaken to a tropical depression near 31.9N 86.0W late tonight, then reach 33.2N 84.0W Thu afternoon and weaken to a remnant low near 34.2N 81.4W late Thu night and dissipate Fri afternoon. Elsewhere, an area of low pressure over the SW Gulf will meander over the southern Gulf during the next several days, with potential to become a tropical cyclone. A weak front will move into the northern Gulf on Sat followed by fresh northeast winds. Swells from Sally over most of the eastern and central Gulf will slowly subside through Fri. CARIBBEAN SEA... An upper level inverted trough is giving way to scattered moderate convection in the central Caribbean from 13N-19N between 76W-81W. Isolated thunderstorms associated with the monsoon trough are along the coasts of Colombia and Panama. Light to gentle trades are seen across the basin. Seas 3-6 ft. A relatively weak pressure pattern will maintain gentle to moderate trades through early next week, with fresh trades pulsing over the south-central Caribbean. ATLANTIC OCEAN... A surface trough, which are the remnants of Rene, is over the central Atlantic from 30N53W to 26N55W. No significant convection is associated with this feature. Outside of the tropical systems, high pressure ridging extends across the basin with light to gentle winds. Seas 3-6 ft in the western Atlantic and 5-7 ft in the central Atlantic. Hurricane Teddy will move to near 18.6N 52.0W late tonight with maximum sustained winds 90 kt gusts 110 kt, and to strengthen to a major hurricane as it moves to near 20.0N 53.4W Thu afternoon with maximum sustained winds 100 kt gusts 120 kt, to near 21.5N 54.9W late Thu night with maximum sustained winds 105 kt gusts 130 kt and to near 23.0N 56.3W Fri afternoon. Teddy is forecast to begin to weaken as it reaches near 24.8N 58.0W late Fri night with maximum sustained winds 100 kt gusts 120 kt, to near 26.5N 60.2W Sat afternoon, to near 29.5N 63.6W Sun afternoon with maximum sustained 90 kt gusts 110 kt and to north of the area near 33.3N 64.6W Mon afternoon. A strong cold front will move over the northwest forecast waters Sat through Sun followed by strong northeast winds. Large northeast swell will impact the tropical N Atlantic waters through early next week. $$ AReinhart