000 AXNT20 KNHC 152301 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sat Sep 16 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 2230 UTC. ...SPECIAL FEATURES... Hurricane Lee is centered near 37.9N 66.7W at 15/2100 UTC or 430 nm SSW of Halifax Nova Scotia, moving N at 17 kt. Estimated minimum central pressure is 965 mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt. Scattered moderate to strong convection is N of 36N between 65W-73W. Seas in excess of 12 ft are expected within 440 nm NE quadrant, 480 nm SE quadrant, 500 nm SW quadrant, and 410 nm NW quadrant, peaking to 45 ft. On the forecast track, the center of Lee will continue to move farther away from Bermuda and approach the coast of New England and Atlantic Canada through Saturday. Lee is then expected to turn toward the north-northeast and northeast and move across Atlantic Canada Saturday night and Sunday. Swells generated by Lee are affecting the northern Leeward Islands, the British and U.S. Virgin Islands, Puerto Rico, Hispaniola, the Turks and Caicos Islands, the Bahamas, Bermuda, the east coast of the United States, and Atlantic Canada. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office for details. Tropical Storm (T.S.) Margot is centered near 36.0N 37.9W at 15/2100 UTC or 530 nm W of the Azores, moving SE at 3 kt. Estimated minimum central pressure is 990 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Seas of excess of 12 ft are within 400 nm N semicircle, 260 NM SE quadrant, and 280 nm quadrant, peaking to 22 ft. Scattered moderate convection is from 34N-39N between 30W-39W. Some additional weakening is forecast during the next couple of days. Swells generated by Margot will continue to affect the Azores for the next several days. These swells are likely to cause life- threatening surf and rip current conditions. Please consult products from your local weather office for details. Please read the latest High Sea Forecast issued by the Ocean Prediction Center at website - https://www.ocean.weather.gov/shtml/NFDHSFAT1.php for more information on Lee and Margot. Tropical Depression (T.D.) Fifteen is centered near 14.4N 43.8W at 15/1500 UTC or 1015 nm E of the Lesser Antilles, and moving NW at 10 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained winds are 30 kt with gusts to 40 kt. Seas are peaking around 10 ft near and just N of the center. Scattered moderate convection is from 08N-23N between 37W-47W. Gradual strengthening is forecast during the next day or so, but a faster rate of intensification is predicted later this weekend and early next week. The depression is forecast to become a tropical storm on Saturday and could become a hurricane late this weekend or 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 for more information. For the latest NHC Forecast/Advisory and Public Advisories on all three system, please visit www.hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave is near 27W from 12N southward, and moving west at 5 to 10 kt. Scattered moderate convection is evident from 09N to 12N between 23W and 29W. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic near 14N17W to 13N36W. Scattered showers are noted within 300 nm S of the boundary. analysis. The eastern end of the East Pacific monsoon trough is triggering scattered showers and scattered thunderstorms across the Caribbean waters north of Costa Rica and Panama. ...GULF OF MEXICO... A stationary front extends eastward across the coast of Texas New Orleans, Louisiana to the Florida panhandle. Scattered showers and isolated thunderstorms are occurring near and up to 60 nm S of the front. A surface trough is analyzed over Bay of Campeche with no significant convection. Elsewhere, a 1015 mb high over the central Gulf is providing light to gentle with locally moderate winds and seas of 1 to 3 ft across the entire Gulf. For the forecast, the weak ridge across the northern Gulf will dominate the basin through the weekend, supporting mainly moderate or weaker winds along with slight seas. Winds will pulse to moderate to fresh W-NW of the Yucatan Peninsula each evening through the weekend. A weak cold front may drop into the NE Gulf early next week with new high pres building in behind it. ...CARIBBEAN SEA... Refer to the Monsoon Trough/ITCZ section for convection in the basin. The presence of Hurricane Lee at the northwestern Atlantic is supporting a modest trade-wind pattern across much of the basin. Fresh to strong easterly winds and seas of 5 to 7 ft are evident at the south-central basin north of Colombia and northwestern Venezuela. Moderate to fresh ENE to ESE winds and 2 to 4 ft seas are found at the north-central basin. Light to gentle winds and seas at 1 to 3 ft are present north of Costa Rica and Panama. Gentle to moderate ENE to ESE winds and 3 to 5 ft seas prevail for the rest of the basin. For the forecast, northerly swell affecting the NE Caribbean Passages will gradually subside tonight, then may build again early next week due to T.D. Fifteen which is forecast to remain NE of the area. Otherwise, moderate to fresh trades will dominate the Central Caribbean, locally strong, with gentle to moderate winds elsewhere. ...ATLANTIC OCEAN... Please, read the SPECIAL FEATURES section, for details about Hurricane Lee, T.S. Margot, and T.D. Fifteen. Convergent southerly winds feeding toward Hurricane Lee are causing scattered moderate convection north of Puerto Rico and the Virgin Islands from 20N to 30N between 60W and 68W. An elongated upper-level low near 24N55W is generating scattered moderate convection from 19N to 30N between 46W and 53W. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections for additional weather in the Atlantic Basin. North of 28N, moderate to fresh SW to NW winds and seas of 12 to 16 ft are noted between 58W and 75W, and gentle to moderate NE to NW winds and seas at 8 to 11 ft are noted between 75W and the Georgia-Florida coast. Light to gentle winds and 8 to 11 ft seas in moderate to large northerly swell dominate from 20N to 28N and W of 50W. At the central and eastern Atlantic outside the direct impact of T.D. Fifteen, moderate to fresh winds and seas of 8 to 10 ft exist N of 30N between 35W-50W. Otherwise, gentle to moderate NNE to E winds and 5 to 7 ft seas in mixed northerly and northeasterly swells are seen from north of 14N between the Africa coast and 50W, including the Canary and Cabo Verde Islands. Gentle to moderate S to SW winds and seas of 5 to 7 ft in moderate southerly swell are evident from the Equator to 17N between the central Africa coast and 50W. Light to gentle winds and seas at 5 to 8 ft in moderate NW swell prevail for the rest of the Atlantic Basin. For the forecast W of 55W, Hurricane Lee will continue to move N away from the area, while associated large northerly swell gradually decays through the weekend. T.D. Fifteen will move to 16.7N 45.0W Sat morning, strengthen to a tropical storm near 18.5N 46.6W Sat afternoon, 20.4N 48.4W Sun morning, 22.0N 50.1W Sun afternoon, strengthen to a hurricane near 23.6N 51.7W Mon morning, and 25.1N 53.6W Mon afternoon. Fifteen will change little in intensity as it moves to 28.0N 57.3W Tue afternoon. Otherwise, high pres will prevail across the waters through the weekend. A weak cold front may move off the SE U.S. coast early next week with new high pres building down behind it. $$ ERA