000 AXNT20 KNHC 101751 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sun Sep 10 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 21.6N 61.0W at 10/1500 UTC or 230 nm NNE of the Northern Leeward Islands, moving WNW at 7 kt. Estimated minimum central pressure is 958 mb. Maximum sustained wind speed is 95 kt with gusts to 115 kt. Peak seas are estimated around 36 ft near the center. Numerous moderate to scattered strong convection is seen within 75 nm N and 164 nm across the SW semicircle. Scattered moderate to strong convection is present elsewhere up to 250 nm E and 180 nm W of the center. A slower west- northwestward motion is expected during the next few days. And some strengthening is forecast during the next couple of days. 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 couple of days. 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 are expected to begin along much of the U.S. East Coast later today and worsen through this week. Please consult products from your local weather office. Tropical Storm Margot is centered near 23.0N 40.0W at 10/1500 UTC or 990 nm WNW of the Cabo Verde Islands, moving NNW at 8 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Peak seas are near 19 ft near the center. Numerous moderate to strong convection is near and north of the center within 130 nm, while scattered moderate convection is seen farther northeast and east from 21N to 29N between 33W and 41W. Margot is expected to gradually turn toward the N during the next couple of days. Additional strengthening is forecast, and Margot is likely to become a hurricane within the next couple of days. 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... An eastern Atlantic tropical wave is analyzed along 27.5W from 18N to 06N, with a 1012 mb low center (Invest AL97) near 13.5N27.5W. It is moving westward at 5 to 10 kt. Scattered moderate to isolated strong convection is noted from 12N to 15N between 28W and 31W. 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. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 19N16.5W then reaches southwestward through the aforementioned AL97 to 13.5N30W. It resumes farther west from 14N39W to 07N48W. The ITCZ continues westward from 07N49W to 08N56W. Numerous moderate to strong convection is present south of the first monsoon trough segment from 06N to 14N between the Senegal- Guinea coast and 23W. Scattered moderate convection is seen from 07N to 13N between 33W and 40W. The eastern end of the East Pacific monsoon trough is triggering numerous heavy showers and scattered thunderstorms across the Caribbean waters just north of Panama and northwestern Colombia to the south of 14N. ...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 are seen near this front. A surface trough over the Bay of Campeche is producing scattered showers and isolated thunderstorms across the area. Outside of convection, modest surface ridging is supporting light to gentle winds and seas at 1 to 2 ft over 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. 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 is near 21.6N 61.0W at 11 AM EDT, and is moving west-northwest at 7 kt. Maximum sustained winds are 95 kt with gusts to 115 kt, and the minimum central pressure is 958 mb. Lee will move to 22.3N 62.1W this evening, 23.0N 63.3W Mon morning, 23.4N 64.5W Mon evening, 23.8N 65.6W Tue morning, 24.2N 66.5W Tue evening, and 24.7N 67.2W Wed morning. Lee will change little in intensity as it moves to near 27.3N 67.9W early Thu. 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 this afternoon 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 is near 21.6N 61.0W at 11 AM EDT, and is moving west-northwest at 7 kt. Maximum sustained winds are 95 kt with gusts to 115 kt, and the minimum central pressure is 958 mb. Lee will move to 22.3N 62.1W this evening, 23.0N 63.3W Mon morning, 23.4N 64.5W Mon evening, 23.8N 65.6W Tue morning, 24.2N 66.5W Tue evening, and 24.7N 67.2W Wed morning. Lee will change little in intensity as it moves to near 27.3N 67.9W early Thu. Large E to SE swell dominating the waters east of 73W will continue to propagate westward across the Atlc, reaching the central Bahamas and 75W this evening, the NW Bahamas and 78W Mon evening, and the Florida coasts Tue afternoon. $$ KRV