000 AXNT20 KNHC 091722 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sat Sep 9 2023 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 1200 UTC surface analysis and satellite imagery through 1745 UTC. ...SPECIAL FEATURES... Hurricane Lee is centered near 20.3N 58.2W at 09/1500 UTC or 300 nm ENE of the Northern Leeward Islands, moving WNW at 10 kt. Estimated minimum central pressure is 957 mb. Maximum sustained wind speed is 100 kt with gusts to 120 kt. Peak seas range around 41 ft, with the 12 ft sea radii extending from the center 240 nm NE...150 nm SE...210 nm SW...and 330 nm NW quadrants. Satellite imagery shows that deep convection continues to pulse near the center of Lee. Numerous moderate to strong convection is seen from the center up to 114 nm in the SE semicircle, and 80 nm in the E semicircle. Scattered moderate convection is evident elsewhere from 17N to 23.8N between 53W and 61W. Lee is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Little change in strength is expected today, but gradual restrengthening is forecast to occur on Sunday and Monday. Lee is expected to continue on a W-NW motion and through early next week with a significant decrease in forward speed beginning later today and Sunday. On the forecast track, Lee is expected to pass well to the north of the northern Leeward Islands, the Virgin Islands, and Puerto Rico into early next week. Dangerous surf and life-threatening rip currents are affecting portions of the northern Leeward Islands. These conditions are spreading westward and northward and will begin affecting Puerto Rico, Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda later today and Sunday. Tropical Storm Margot is centered near 20.5N 38.0W at 09/1500 UTC or 840 nm WNW of the Cabo Verde Islands, moving WNW at 10 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Peak seas of 12 to 15 ft extend outward from the center up to 120 nm in the NE semicircle, and 15 nm in the S semicircle. Latest satellite imagery shows numerous moderate to strong convection occurring in a band extending NE from the center, from 20N to 24N between 32W and 38W. Margot is moving toward the west-northwest and a west-northwestward to northwestward motion is expected during the next day or so. A north-northwestward to northward motion is forecast to begin by late Sunday. Gradual strengthening is forecast over the next several days, and Margot is forecast to become a hurricane early next week. 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 on Lee and Margot at www.hurricanes.gov for more details. ...TROPICAL WAVES... A eastern Atlantic tropical wave is analyzed near 24W from the Cabo Verde Islands southward, and moving westward around 10 kt. Scattered moderate convection is noted from 11N to the southern Cabo Verde Islands between 24W and 28W. This wave is expected to become entrained in the prevailing southeasterly wind flow that is guiding Margot, which will weaken it and transport it off to the NW through Sun. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 17N16.5W then reaches southwestward to south of the Cabo Verde Islands at 14.5N24W, before resuming from 12N34W to 07N43W. The ITCZ begins at 07N43W and ends at 07N49W. Scattered moderate convection is present south of the trough from 05N to 12N between the Sierra Leone coast and 21W. The eastern end of the East Pacific monsoon trough is triggering scattered showers and thunderstorms across the Caribbean waters of Costa Rica, Panama and Colombia to the south of 10.5N. ...GULF OF MEXICO... A very weak stationary front curves westward from the Florida Panhandle southward to near 27N and across the Louisiana/Texas border coastal waters. Isolated thunderstorms are occurring near the front. However, isolated small clusters of showers and moderate thunderstorms are occurring across the Florida Big Bend, and offshore of south-central Texas. In addition, an outflow boundary has developed in the offshore waters of south- central Texas. A surface trough near the west coast of the Yucatan Peninsula is causing isolated showers and thunderstorms across the Bay of Campeche. Otherwise outside of convection, modest ridging related to a 1016 mb high along the E Texas coast is producing light to gentle winds with 1 to 2 ft seas across the basin. For the forecast, a weak ridge will dominate the Gulf waters throughout the forecast period supporting light to moderate winds. ...CARIBBEAN SEA... Please read the SPECIAL FEATURES section about large swell generated by Major Hurricane Lee impacting the northeast Caribbean islands. An upper-level trough extends southward from western Cuba to northwestern Colombia. Combining with modest convergent easterly trades, widely scattered showers and thunderstorms are occurring across the Gulf of Honduras, and south of 10.5N, along the monsoon trough. A weak trade-wind pattern is persisting across east and west portions of the basin this morning, with fresh to locally strong ENE to E winds and seas of 6 to 9 ft occurring in the south- central basin, including the Gulf of Venezuela. Strong ENE swell from Lee has begun to enter the passages of the NE Caribbean recently and will build throughout the day as this swell propagates westward across the eastern basin. For the forecast, Hurricane Lee is near 20.3N 58.2W at 11 AM EDT, and is moving west-northwest at 10 kt. Maximum sustained winds are 100 kt with gusts to 120 kt, and the minimum central pressure is 957 mb. Lee will move to 21.0N 59.3W this evening, 21.7N 60.6W Sun morning, 22.4N 61.9W Sun evening, 22.9N 63.1W Mon morning, 23.3N 64.2W Mon evening, and 23.6N 65.3W Tue morning. Lee will change little in intensity as it moves to near 24.4N 67.0W early Wednesday. In the Caribbean, moderate to fresh trade winds will continue in the central and E Caribbean through the weekend. Large easterly swell over the tropical Atlantic waters has reached the passages of the NE Caribbean this morning, and will reach the Anegada Passage by midday today, and the Mona Passage Sun. ...ATLANTIC OCEAN... Please see the SPECIAL FEATURES section above for details on Major Hurricane Lee and on Tropical Storm Margot. For convection information across the tropical Atlantic, please see the TROPICAL WAVES and MONSOON TROUGH/ITCZ sections. A modest but persistent surface trough extends northeastward from the central Bahamas to west of Bermuda near 31N72W. Scattered showers and isolated thunderstorms are present near and up to 180 nm east side of this feature, including the rest of the Bahamas. An upper-level low at the central Atlantic near 29N45W is producing scattered moderate convection north of 28N between 43W and 48W North of 20N, fresh to locally strong NE to ESE peripheral winds of Hurricane Lee and Tropical Storm Margot are found northward to 27N between 51W and 64W, and between 32W and 42W respectively. Otherwise, gentle to moderate NE to SE winds and seas of 5 to 8 ft in mixed swell dominates north of 24N between 25W and the Georgia-Florida coast. From 05N to 24N outside the direct influence of Lee and Margot, gentle to moderate with locally fresh NE to SE winds and 6 to 10 ft seas in mixed swells exist between 30W and the Lesser Antilles. Near the Canary Islands, gentle to moderate with locally fresh NNE to NE trades and seas at 5 to 8 ft are found north of 18N between the Africa coast and 25W. Near the Cabo Verde Islands, gentle monsoonal winds and 3 to 5 ft seas are seen south of 18N between the central Africa coast and 23W. Gentle to moderate with locally fresh southerly winds and 6 to 10 ft seas in moderate to large southerly swell prevail for the remainder of the Atlantic Basin. For the forecast W of 55W, Hurricane Lee is near 20.3N 58.2W at 11 AM EDT, and is moving west-northwest at 10 kt. Maximum sustained winds are 100 kt with gusts to 120 kt, and the minimum central pressure is 957 mb. Lee will move to 21.0N 59.3W this evening, 21.7N 60.6W Sun morning, 22.4N 61.9W Sun evening, 22.9N 63.1W Mon morning, 23.3N 64.2W Mon evening, and 23.6N 65.3W Tue morning. Lee will change little in intensity as it moves to near 24.4N 67.0W early Wednesday. Large easterly swell over the passages of the NE Caribbean will reach the Anegada Passage by midday today, the Mona Passage on Sun, the Turks and Caicos Islands Sun evening and the southeastern Bahamas Mon. $$ KRV