000 AXNT20 KNHC 162314 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sun Sep 17 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 2300 UTC. ...SPECIAL FEATURES... Post-Tropical Cyclone Lee is centered near 44.5N 66.1W at 16/2100 UTC or 40 nm ESE of Eastport Maine, moving N at 14 kt. Estimated minimum central pressure is 970 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Seas are peaking near 36 kt near the center. Steady weakening is forecast during the next couple of days. Swells generated by Lee are affecting 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 Margot is centered near 34.3N 39.6W at 16/2100 UTC or 650 nm WSW of the Azores, moving W at 7 kt. Estimated minimum central pressure is 996 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. 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. Gradual weakening is forecast during the next couple of days, though slight fluctuations in intensity are possible. Please read the latest HIGH SEAS 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 Fifteen is centered near 20.8N 47.1W at 16/2100 UTC or 870 nm ENE of the Lesser Antilles, moving NNW at 14 kt. Estimated minimum central pressure is 1006 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are around 13 ft near the center. Scattered moderate to isolated strong convection near and north of the center from 20N to 26N between 43W and 49W. Some strengthening is forecast during the next 48 hours, and the system could become a hurricane by 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. The latest NHC Forecast/Advisories and Public Advisories for all three systems can be found at www.hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave is near 33W from 12N southward, and moving westward at 10 to 15 kt. Scattered showers are noted within 100 nm on either side of the wave axis. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic near 13N17W to 10N36W. Scattered showers are noted within 100 nm of either side of the boundary. The eastern end of the East Pacific monsoon trough is triggering scattered showers and thunderstorms across the southwestern Caribbean S of 13N and W of 73W. ...GULF OF MEXICO... A surface trough extends across the NW gulf waters enhancing scattered showers N of 26N and W of 95W. Another trough extends across the Florida peninsula with scattered showers E of 82W. Elsewhere, a 1015 mb high is centered near 26N91W and is promoting light to gentle winds and seas of 1 to 3 ft across the entire Gulf. For the forecast, the high will dominate the basin through early Sun, supporting mainly light to gentle anticyclonic winds along with slight seas. A weak cold front is forecast to move off New Orleans and Mississippi into the N-central and NE Gulf Sun followed by N to NW moderate winds and isolated to scattered showers. The front is forecast to move E of the area by Sun night, with a reinforcing from Mon. A weak surface ridge will develop afterward, supporting gentle to moderate NE to E winds through Wed, freshening in the NE Gulf Thu. Otherwise, winds will pulse to moderate to fresh W-NW of the Yucatan Peninsula this evening and Sun evening. ...CARIBBEAN SEA... Scattered showers and isolated thunderstorms induced by island heating are found near the southern coast of Cuba, Hispaniola and Jamaica. Refer to the Monsoon Trough/ITCZ section for additional weather in the Caribbean Basin. A modest trade-wind regime continue across most of the basin. Moderate to fresh easterly winds and seas of 4 to 6 ft are present at the south-central basin. Gentle to moderate ENE to E winds and 3 to 4 ft seas are noted at the north-central and west-central basin. Gentle to moderate monsoonal winds and seas at 2 to 4 ft exist near Costa Rica and Panama. Gentle easterly winds and 1 to 3 ft seas prevail for the rest of the basin. For the forecast, northerly swell affecting the NE Caribbean Passages will gradually subside tonight, then is forecast to build back slightly again there Sun night through Wed due to Tropical Depression Fifteen, which is forecast to remain well NE of the area while strengthening. Otherwise, moderate to fresh trades will prevail across the Central Caribbean, locally fresh to strong off Colombia, while gentle to moderate winds will dominate elsewhere through the forecast period. ...ATLANTIC OCEAN... Please, read the Special Features section above for details on Post-Tropical Cyclone Lee, Tropical Storm Margot and Tropical Depression Fifteen. A stationary front extends east-northeastward from near Cape Canaveral, Florida to near Bermuda. No significant convection is noted with this front at this time. A surface trough across the Florida Peninsula is enhancing scattered showers W of 78W. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections at the beginning for additional weather in the Atlantic Basin. Moderate to large northerly swell generated by Post-Tropical Cyclone Lee and T.S. Margot is maintaining 8 to 11 ft seas north of 25N between 33W and 77W. Elsewhere, light to gentle winds with seas at 5 to 7 ft in moderate mixed swells are found from 18N to 25N between 50W and the Georgia-Florida coast. For the eastern Atlantic, gentle to moderate NNE to E trades and seas of 4 to 6 ft are found north of 10N between the Africa coast and 30W, including the Canary and Cabo Verde Islands. Farther west outside the direct impact from Tropical Depression Fifteen, gentle to moderate NW to NE winds and seas of 4 to 6 ft in moderate northwesterly swell are evident from 10N to 20N between 40W and the Lesser Antilles. Light to gentle southerly and monsoonal winds with 5 to 7 ft in moderate southerly swell prevail for the rest of the Atlantic Basin. For the forecast W of 55W, Tropical Depression Fifteen will strengthen to a tropical storm near 22.3N 48.2W Sun morning, move to 24.2N 49.7W Sun afternoon, 25.6N 51.1W Mon morning, strengthen to a hurricane near 26.9N 52.9W Mon afternoon, 28.3N 54.8W Tue morning, and 30.0N 56.4W Tue afternoon. Fifteen will change little in intensity as it moves well N of the area to 34.6N 57.3W Wed afternoon. Otherwise, high pres will prevail across the waters through the weekend. A weak cold front is forecast to move off the SE U.S. coast early next week with new high pres building down behind it. The front may stall and linger along 27N/28N through mid-week. $$ ERA