095 AXNT20 KNHC 100555 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 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 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... Hurricane Lee is centered near 21.0N 59.9W at 10/0300 UTC or 250 nm NE of the Northern Leeward Islands, and moving WNW at 8 kt. Estimated minimum central pressure is 962 mb. Maximum sustained winds are 90 kt with gusts to 110 kt. Peak seas range from 38 to 40 ft near the center. Numerous moderate to scattered strong convection is seen near and up to 100 nm in a SW semicircle from the center. Scattered moderate convection is present up to 200 nm in a NE semicircle from the center. Lee is expected to slow down a little over the next few days, while passing well north of the northern Leeward Islands, Virgin Islands and Puerto Rico into early next week. Lee remains a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Gradual restrengthening is anticipated during the next couple of days. Large swells generated by Lee are affecting the Leeward Islands and reaching Puerto Rico and the Virgin Islands later tonight. These swells will spread westward to Hispaniola, the Turks and Caicos Islands, and the Bahamas on Sun, and then northward to Bermuda Sun night. 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 on Sun and worsen through the week. Please consult products from your local weather office. Tropical Storm Margot is centered near 21.6N 39.1W at 10/0300 UTC or 920 nm WNW of the Cabo Verde Islands, and moving NW at 8 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained winds are 45 kt with gusts to 55 kt. Peak seas are near 16 ft near the center. Numerous moderate convection is near and northeast of the center from 21N to 24N between 35W and 39W. Scattered moderate convection is seen farther east from 18N to 21N between 32W and 34W. Margot is expected to gradually turn toward the NNW to N with little change in forward speed through Mon night. Gradual strengthening is forecast over the next few days, and Margot might 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... An eastern Atlantic tropical wave is just west of the Cabo Verde Islands near 26W from 18N southward through a 1011 mb low (Invest AL97) at 13N26W. It is moving westward at 5 to 10 kt. Scattered moderate convection is noted from 08N to 15N between 26W and 32W. Environmental conditions are marginally favorable for additional development on this system as it slowly moves westward. There is a low chance on tropical cyclone formation for the next 7 days. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic near Nouakchott, Mauritania then reaches southwestward through the aforementioned AL97 to southwest of the Cabo Verde Islands at 13N29W. It resumes farther west from 13N39W to 08N43W. An ITCZ continues westward from 08N43W to 08N53W. Numerous moderate to isolated strong convection is present south of the first monsoon trough segment from 08N to 14N between the Senegal-Guinea coast and 18W. Scattered moderate convection is seen mostly south and east of the second monsoon trough segment from 07N to 10N between 32W and 43W. Similar conditions are found near and up to 60 nm south of the ITCZ. 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. ...GULF OF MEXICO... A very weak stationary front curves westward from the Florida Panhandle through the north-central Gulf to just west of Galveston, Texas. Isolated thunderstorms are seen near this front. A surface trough near the west coast of the Yucatan Peninsula is producing scattered showers and isolated thunderstorms at the Bay of Campeche. Modest surface ridging is supporting light to gentle winds and seas at 1 to 2 ft over the eastern Gulf, including the Yucatan Channel. Gentle to locally moderate N to ENE winds and 2 to 4 ft seas prevail for the western Gulf, including the Bay of Campeche. For the forecast, weak ridging will continue to dominate the Gulf waters throughout midweek next week, supporting light to moderate winds and slight to moderate seas. ...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 persists from the Yucatan Channel southeastward to northern Colombia. Divergent southerly winds north of its axis are coupling with modest convergent northeasterly winds to cause widely scattered showers and isolated thunderstorms from the Gulf of Honduras eastward across the Cayman Islands, Jamaica and Hispaniola to Puerto Rico. Refer to the Monsoon Trough/ITCZ sections for additional weather in the Caribbean Basin. A weak trade-wind regime continues across much of the basin, except near Panama and northwestern Colombia. Moderate to fresh ENE to E winds and seas of 5 to 7 ft are evident at the south-central basin. Mainly gentle E winds and 2 to 4 ft seas exist at the northwestern basin. Light to gentle winds with seas at 2 to 4 ft are noted near Panama and northwestern Colombia. Gentle to moderate ENE to ESE winds and 3 to 5 ft seas prevail elsewhere in the basin, including the Windward Passage. For the forecast, moderate to fresh trade winds will continue in the central and eastern basin through the weekend. Large easterly swell from Lee is dominating the Atlantic waters of the northern Leeward Islands tonight and will gradually shift to northeast and then north, while moving through the Caribbean Passages and into the northeastern Caribbean waters Sun through Tue night. ...ATLANTIC OCEAN... Please see the SPECIAL FEATURES section at the beginning for details on Major Hurricane Lee and on Tropical Storm Margot. A surface trough runs northward from the northwest Bahamas to near 31N77W. Isolated thunderstorms exist near and up to 180 nm east of this feature. An upper-level low at the central Atlantic near 30N43W is generating widely scattered moderate convection from 24N to 30N between 41W and 50W. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections for additional weather in the Atlantic Basin. Outside the influence of Lee and Margot, a 1022 mb high near 33N34W is supporting gentle to moderate with locally fresh NNE to E winds and 5 to 8 ft seas in mixed swells north of 20N between 30W and 65W. To the west, gentle to locally moderate E to SE winds and seas of 3 to 5 ft are found north of 20N between 65W and the Georgia-Florida coast. Near the Canary Islands, gentle NNE trades and seas at 2 to 4 ft are evident north of 23N between the Africa coast and 30W. Near the Cabo Verde Islands, gentle to moderate with locally fresh WNW to NE winds exist from 14N to 22N between the central Africa coast and 30W. To the south from 06N to 14N between the Guinea-Liberia coast and 30W, light to gentle monsoonal winds and 5 to 7 ft seas in moderate southerly swell are present. For the tropical Atlantic, gentle with locally moderate NE to SE 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. For the forecast W of 55W, Hurricane Lee will reach near 21.6N 60.9W Sun morning, near 22.4N 62.3W Sun evening and near 23.0N 63.5W Mon morning. It will then move to near 23.3N 64.7W Mon evening, near 23.6N 65.6W Tue morning and near 24.0N 66.6W Tue evening. Large E to SE swell is dominating the waters east of 67W this evening, and will reach 70W Sun morning, reaching the Turks and Caicos Islands Sun evening, and the southeast and central Bahamas on Mon. $$ Forecaster Chan