453 AXNT20 KNHC 090557 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 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 0000 UTC surface analysis and satellite imagery through 0530 UTC. ...SPECIAL FEATURES... Major Hurricane Lee is centered near 19.3N 56.5W at 09/0300 UTC or 380 nm E of the Northern Leeward Islands, and moving WNW at 11 kt. Estimated minimum central pressure is 963 mb. Maximum sustained winds are 100 kt with gusts to 120 kt. Peak seas range from 40 to 42 ft, with the 12 ft sea radii extending from the center up to 300 nm of in a N semicircle, and 210 nm in a S semicircle. Latest satellite imagery shows that the eye of Lee is no longer visible with some banding features still present to the east and south. Numerous moderate to scattered strong convection is seen from the center up to 100 nm in a SW semicircle, and 70 nm in a NE semicircle. Scattered moderate convection is evident farther north from 21N to 22N between 53W and 58W, and southeast from 16N to 21N between 52W and 55W. Lee is forecast to maintain its current motion through early next week with a significant decrease in forward speed starting Sun. Lee is expected to pass well north of the northern Leeward Islands this weekend, then the Virgin Islands and Puerto Rico early next week. Lee is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some fluctuations in intensity are likely over the next few days, however Lee is expected to remain a powerful hurricane through early next week. Large swells generated by Lee are affecting the Leeward Islands, and will reach the Virgin Islands and Puerto Rico Sat night, and Hispaniola on Sun. Eventually, they will arrive at the Turks and Caicos Islands, Bahamas and Bermuda on Mon. These swells are likely to cause life-threatening surf and rip current conditions. Dangerous surf and rip currents are expected to begin along most of the U.S. East Coast beginning Sun and Mon. Tropical Storm Margot over the eastern Atlantic is centered near 19.5N 35.8W at 09/0300 UTC or 705 nm WNW of the Cabo Verde Islands, and moving WNW at 15 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained winds are 35 kt with gusts to 45 kt. Peak seas of 12 to 14 ft extend outward from the center for up to 90 nm in a N semicircle, and 15 nm in a S semicircle. Latest satellite imagery shows Margot remains disorganized with numerous moderate to isolated strong convection mainly up to 120 nm from the center in a N semicircle. Margot is forecast to maintain its present motion through Sat night, then turns toward the northwestward with a decrease in forward motion starting Sun. Some gradual strengthening is forecast the next several days, with Margot forecast to become a hurricane early next week. Peak seas will gradually build near the center, possibly reaching 20 to 25 ft 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 far eastern Atlantic tropical wave is near 22W 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 21W and 25W. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic near Dakar, Senegal then reaches southwestward to south of the Cabo Verde Islands at 13N23W, before resuming from 12N33W to 08N37W. Widely scattered moderate convection is present south of the trough from 05N to 09N between the Sierra Leone coast and 19W. An ITCZ continues westward from 08N37W to 07N47W. Widely scattered moderate convection is seen near and up to 200 nm south of the ITCZ. The eastern end of the East Pacific monsoon trough is triggering scattered showers and isolated thunderstorms across the Caribbean waters near Costa Rica and Panama. ...GULF OF MEXICO... A very weak stationary front curves westward from the Florida Panhandle across the north-central Gulf to near Galveston, Texas. Isolated thunderstorms are found near this feature. A surface trough near the west coast of the Yucatan Peninsula is causing scattered showers and isolated thunderstorms across the central and eastern Bay of Campeche, and near the Yucatan Channel. Otherwise, modest ridging related to a 1015 mb high just west of New Orleans are providing light to gentle winds with 1 to 2 ft seas for the north- central and northeastern Gulf. Gentle to locally moderate E to SE winds and seas of 2 to 4 ft prevail for the rest of the Gulf. Foe the forecast, the weak ridging will dominate the Gulf waters through midweek next week, supporting only light to moderate winds. Sporadic thunderstorms will continue overnight near the stationary front. ...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 northern Colombia. Combining with modest convergent easterly trades, widely scattered showers and isolated thunderstorms are occurring from just south of the Yucatan Channel eastward across the Cayman Islands and Jamaica to Haiti. Refer to the Monsoon Trough/ITCZ section for additional weather in the Caribbean Basin. A weak trade-wind pattern is persisting across much of the basin. Fresh to locally strong ENE to E winds and seas of 6 to 8 ft are evident at the south- central basin, including the Gulf of Venezuela. Moderate to fresh NE to E winds and 4 to 6 ft seas are noted at the north- central and southwestern basin, except light to gentle winds with seas at 2 to 4 ft near Costa Rica and Panama. Gentle to moderate E to ESE winds and 3 to 5 ft seas prevail elsewhere in the basin. For the forecast, moderate to fresh trade winds will continue in the central and eastern basin through the weekend. Large easterly swell over the tropical Atlantic waters is currently east of 62W and will reach the passages of the northeast Caribbean early Sat, the Anegada Passage by midday Sat, 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. A modest but persistent surface trough extends northeastward from the northwest Bahamas to west of Bermuda near 31N70W. Widely scattered showers and isolated thunderstorms are present near and up to 230 nm southeast of this feature, including the rest of the Bahamas. An upper-level low at the central Atlantic near 30N43W is producing scattered moderate convection north of 26N between 42W and 47W. Another surface trough near 23N42W is generating widely scattered moderate convection from 17N to 27N between 39W and 43W. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections for additional weather in the Atlantic Basin. North of 22N, fresh to locally strong NE to ESE peripheral winds of Hurricane Lee and Tropical Storm Margot are found northward to 24N between 50W and 60W, and between 31W and 42W respectively. Otherwise, gentle to moderate NE to SE winds and seas of 5 to 9 ft in mixed swells dominate north of 22N between 25W and the Georgia- Florida coast. From 05N to 22N 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 4 to 7 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 30W. 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 will move to near 20.0N 57.8W Sat morning, near 20.8N 59.4W Sat evening and near 21.5N 60.8W Sun morning. It should the move to near 22.0N 62.0W Sun evening, near 22.5N 63.2W Mon morning, near 22.8N 64.2W Mon evening, and near 23.5N 66.4W Tue evening. Large swell from Lee will begin to impact the Anegada Passage and adjacent waters Sat morning, reach the Mona Passage early Sun morning, the Turks and Caicos Islands Sun evening and the southeastern Bahamas Sun night. Beyond Tue, Lee is expected to turn NW then N and slowly weaken. $$ Forecaster Chan