000 AXNT20 KNHC 102348 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Mon Sep 11 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 1800 UTC surface analysis and satellite imagery through 2350 UTC. ...SPECIAL FEATURES... Hurricane Lee is centered near 22.1N 61.7W at 10/2100 UTC or 250 nm NNE of the Northern Leeward Islands, moving WNW at 7 kt. Estimated minimum central pressure is 954 mb. Maximum sustained wind speed is 105 kt with gusts to 130 kt. Peak seas are estimated around 39 ft near the center. Numerous moderate to strong convection is from 20N to 214N between 59W and 64W. Numerous moderate convection is elsewhere from 19N to 26N between 55W and 65W. On the forecast track, Lee is expected to pass well north of the northern Leeward Islands, the Virgin Islands, and Puerto Rico during the next day or two. Lee is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Additional strengthening is forecast during the next day or so. Some fluctuations in intensity are possible on Monday and Tuesday. Swells generated by Lee are affecting portions of the Lesser Antilles, the British and U.S. Virgin Islands, Puerto Rico, Hispaniola, the Turks and Caicos Islands, the Bahamas, and Bermuda. These swells are likely to cause life-threatening surf and rip current conditions. Dangerous surf and rip currents have begun to reach portions of the southeast U.S. East Coast and are forecast to worsen and spread northward along much of the U.S. East Coast during the next couple of days. Please consult products from your local weather office. Tropical Storm Margot is centered near 23.9N 40.1W at 10/2100 UTC or 1020 nm WNW of the Cabo Verde Islands, moving N at 8 kt. Estimated minimum central pressure is 996 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Peak seas are near 20 ft near the center. Numerous moderate convection is from 22N to 25N between 39W and 41W. Scattered moderate isolated strong convection in form of rainbands is from 22N to 33N between 30W and 43W. Margot is expected to continue a northward motion during the next several days. Additional strengthening is forecast, and Margot is likely to become a hurricane on Monday. 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 tropical wave is analyzed along 28W from 18N to 06N, with a 1012 mb low center (Invest AL97) near 13N28W. It is moving westward at 5 to 10 kt. Scattered moderate convection is noted from 09N to 15N between 25W and 35W. Environmental conditions are forecast to become less conducive for development during the next day or so as the disturbance moves slowly westward over the eastern tropical Atlantic. The system is forecast to merge with a larger tropical wave to its east in a couple of days and no further development is expected after that time. There is a low chance of tropical cyclone formation during the next 7 days. A tropical wave came off of the W coast of Africa this afternoon. Its axis is near 18W and extends from 05N to 19N, moving west at 5 to 10 kt. Widely scattered moderate convection is from 05N to 10N between 13W and 26W. Environmental conditions appear conducive for gradual development of this system during the latter part of this week, and a tropical depression could form by next weekend as it moves westward to west-northwestward over the central tropical Atlantic. There is a low chance of tropical cyclone formation during the next 2 days and a medium chance from 3 to 7 days. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 18N16W then reaches southwestward 13N21W to 13N30W. It resumes farther west from 14N40W to 07N49W. The ITCZ continues westward from 07N49W to 09N57W. For information on convection see the Tropical Waves Section. ...GULF OF MEXICO... A very weak stationary front curves westward from the Florida Panhandle through the north-central Gulf to Corpus Christi, Texas. Isolated showers prevails in the vicinity of this front. Otherwise, a weak surface ridge is supporting light to gentle winds E of 92W and moderate northerly winds W of 92W. Seas are slight basin-wide. 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. Please see the MONSOON TROUGH/ITCZ section for convection near the northwestern Colombia offshore waters. A mid to upper-level trough persists from the Yucatan Channel southeastward to northern Colombia. Divergent southerly winds north of its axis are coupling with modest convergent northeasterly winds to produce scattered showers and isolated thunderstorms across the Gulf of Honduras. A weak trade-wind regime continues across much of the basin, except for moderate to locally fresh trades across the southeast and central portions, where seas of 4 to 7 ft prevail. Mainly gentle E to SE winds and 2 to 4 ft seas exist at the northwestern basin. Gentle to moderate E to SE winds and 3 to 5 ft seas prevail elsewhere in the basin, including the Windward Passage. Large E to ENE swell generated from Lee are impacting the coastal waters of the northern Leeward Islands, and bleeding through the Caribbean Passages and into the extreme NE Caribbean waters. For the forecast, Hurricane Lee will move to 22.7N 62.7W Mon morning, 23.3N 63.9W Mon afternoon, 23.8N 65.1W Tue morning, 24.2N 66.2W Tue afternoon, 24.7N 67.0W Wed morning, and 25.6N 67.6W Wed afternoon. Lee will change little in intensity as it moves near 28.9N 68.0W Thu afternoon. In the Caribbean, moderate to fresh trade winds will continue in the central and E Caribbean through Mon. Large easterly swell from Lee is dominating the Atlantic waters from the northern Leeward Islands to the Turks and Caicos Islands. Large swell will gradually become NE and then N, and move through the Caribbean Passages and into the Caribbean waters between the Leeward Islands and the Mona Passage through Wed night. ...ATLANTIC OCEAN... Please see the SPECIAL FEATURES section above for information about Hurricane Lee and Tropical Storm Margot. Please see the TROPICAL WAVES and MONSOON TROUGH/ITCZ for convection in the tropical Atlantic. A surface trough extends northward from southeast Florida to near 30N78W. Widely scattered showers and thunderstorms are noted along and up to 180 nm east of this feature. Outside the influence of Lee, Margot, and AL97, a surface ridge is supporting gentle to moderate NE and 4 to 6 ft seas in mixed swell north of 24N between the west coast of Africa and 32.5W. To the west, gentle to locally moderate E to SE winds and seas of 3 to 5 ft are found north of 20N between 74W and the Georgia- Florida coast. North of the Cabo Verde Islands, moderate to fresh NE winds exist from 16.5N to 25N between the coast of Africa and 30W. To the south from 06N to 14N between the Guinea- Liberia coast and 30W, light to gentle monsoonal winds and 5 to 8 ft seas in moderate southerly swell are present. For the tropical Atlantic, gentle with locally moderate trade winds and seas of 6 to 8 ft in mixed swells dominate from 05N to 20N between 30W and the Lesser Antilles. Gentle to moderate southerly winds and seas of 7 to 10 ft in large southerly swell prevail for the remainder of the Atlantic Basin to the NW of Lee. For the forecast W of 55W, Hurricane Lee will move to 22.7N 62.7W Mon morning, 23.3N 63.9W Mon afternoon, 23.8N 65.1W Tue morning, 24.2N 66.2W Tue afternoon, 24.7N 67.0W Wed morning, and 25.6N 67.6W Wed afternoon. Lee will change little in intensity as it moves near 28.9N 68.0W Thu afternoon. Large E to SE swell dominating the waters east of 73W will continue to propagate westward across the Atlc, reaching the the NW Bahamas and 78W Mon evening, and the Florida coasts Tue afternoon. $$ Ramos