000 AXNT20 KNHC 131730 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Sep 13 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 1700 UTC. ...SPECIAL FEATURES... Major Hurricane Lee is centered near 26.4N 67.2W at 13/1500 UTC or 370 nm SSW of Bermuda, moving NNW at 8 kt. Lee is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Estimated minimum central pressure is 948 mb. Maximum sustained wind speed is 100 kt with gusts to 120 kt. Numerous moderate to strong convection is noted within 140 nm of the center, with scattered moderate convection noted from 18N to 31N between 62W and 71W. The peak seas are currently around 45 ft with the 12 ft seas extending 450 nm in the NW quadrant, 375 nm in the NE and SW quadrants, and 350 nm in the SE quadrant. Lee will turn toward the north by tonight, followed by an increase in speed on Thursday and Friday. On the forecast track, the center of Lee will pass west of Bermuda Thursday and Thursday night and then approach the coast of New England or Atlantic Canada Friday and Saturday. Slow weakening is forecast during the next few days, however, Lee is likely to remain a large and dangerous hurricane into the weekend. 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 affecting portions of the southeastern and mid-Atlantic U.S. coast, and these conditions are forecast to spread northward across New England and Atlantic Canada later today. Please consult products from your local weather office. Hurricane Margot is centered near 34.1N 40.4W at 13/1500 UTC or 690 nm WSW of the Azores, moving NNW at 6 kt. Estimated minimum central pressure is 970 mb. Maximum sustained wind speed is 80 kt with gusts to 100 kt. Scattered to numerous moderate to isolated strong convection is noted within 150 nm in the northern semicircle. Scattered moderate convection is noted from 29N to 37N between 36W and 47W. The peak seas are currently around 32 ft with the 12 ft seas extending within 320 nm in the eastern semicircle, 300 nm in the NW quadrant and 290 nm in the SW quadrant. Margot will continue moving NNW with a gradual decrease in forward speed through early Thursday. Then, Margot is likely to stall or meander within weak steering currents into the weekend. Some weakening is forecast during the next 72 hours. Swells generated by Margot will begin to affect the Azores later today. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. 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. Eastern and Central Tropical Atlantic (AL97): A broad area of low pressure over the eastern tropical Atlantic continues to produce some disorganized showers and thunderstorms. Gradual development of this system is expected over the next few days while the system moves west-northwestward to northwestward at 10 to 15 kt, and a tropical depression is likely to form by this weekend over the central tropical Atlantic. This system has a medium chance of formation in 48 hours and a high chance in 7 days. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is analyzed along 27W from 19N southward, moving W at 10 kt. Scattered moderate convection is noted from 03N to 15N between 24W and 28W. An Atlantic Ocean tropical wave is analyzed along 34W from 19N southward, moving W at 10 to 15 kt. This wave is associated with AL97 mentioned in the Special Features section. Scattered moderate to isolated strong convection is noted from 08N to 17N between 31W and 36W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean from the coast of Senegal near 14N17W to AL97 near 12N34W to 10N49W. There is no ITCZ at this time. Outside of the convection mentioned in the Tropical Waves section, scattered moderate to isolated strong convection is noted from 06N to 18N between 30W and 45W. Numerous moderate to strong convection is noted off the African coast from 05N to 11N and E of 19W. ...GULF OF MEXICO... Surface ridging dominates the Gulf of Mexico anchored by a 1016 mb high pressure near 26N88W. A stationary front is meandering across the northern Gulf coast which is acting as a focal point for isolated thunderstorms in the northern Gulf. Scattered thunderstorms are noted in the southern Bay of Campeche. Isolated thunderstorms are also observed off the Tampa Bay coast. Otherwise, quiescent conditions are noted across the basin. Light to gentle anticyclonic winds prevail across the basin. Buoys and an earlier altimeter pass confirm smooth to slight seas. For the forecast, a weak ridge across the northern Gulf will dominate the basin throughout the forecast period, supporting mainly light to gentle winds N of 24N and gentle to moderate winds S of 24N. Moderate return flow will develop across the W and SW Gulf Thu night. Scattered thunderstorms can be expected across the western Yucatan and eastern Bay of Campeche each late afternoon and evening. ...CARIBBEAN SEA... Please read the Special Features section about the large swell generated by Major Hurricane Lee impacting the northeast Caribbean islands. Northerly swell generated by Lee continues to propagate through the passages of the NE Caribbean, including the Anegada and Mona Passages. Buoys along the N and NW coast of Puerto Rico are reporting seas to 7 to 9 ft this afternoon, with plumes of 5 to 7 ft combined seas extending south through the passages across the northeast Caribbean. In addition, scattered thunderstorms from an outer band of Lee are noted across eastern Hispaniola, the Mona Passage, and across Puerto Rico. Outside of the impacts of Hurricane Lee, scattered thunderstorms are noted in the SW Caribbean along the Eastern Pacific monsoon trough, S of 11N between 75W and 82W in addition to the Gulf of Venezuela. Scattered thunderstorms are also noted in the Gulf of Honduras and the Yucatan Channel. Otherwise, quiescent conditions prevail across the basin. The latest scatterometer depicts gentle to moderate trade winds in the eastern Caribbean with light to gentle wind in the central basin. Gentle to locally moderate winds prevail in the NW Caribbean. Slight seas are noted across the rest of the basin. For the forecast, Hurricane Lee is expected to turn toward the N through Fri and exit the region. Large N-NW swells across the adjacent Atlantic will move through the NE Caribbean Passage through early Thu before gradually diminishing Thu night and then decreasing quickly Fri. Moderate E trade winds will return to the Caribbean on Fri. ...ATLANTIC OCEAN... Please see the Special Features section for information about Major Hurricane Lee, Hurricane Margot, AL97. From the W of Lee to the Bahamas and Florida coast, swells from Lee are impacting the waters across this area. Buoys off the central and northern Florida coast are reporting moderate seas up to 5 ft. Swells of 5 to 8 ft are likely impacting the Atlantic coastlines of the Bahamas and Turks and Caicos. Isolated thunderstorms are noted off the NE Florida coast. Otherwise, light to gentle winds are noted right off the Florida coast with moderate to fresh winds across the Bahamas and Turks and Caicos due to the influence of Lee. Moderate to fresh winds also extend southward to the Atlantic coasts of Hispaniola and Puerto Rico. High pressure extends between Lee and Margot in the central Atlantic. Gentle to moderate winds are noted N of 27N. Fresh to strong winds continue from 28N to 31N between 33W and 43W from the influence of Margot. An area of scattered moderate to isolated strong convection is noted from 18N to 25N between 43W and 52W. Otherwise, light to gentle winds prevail across the central Atlantic. Seas range 8 to 12 ft N of 25N and W of 33W. Seas 4 to 7 ft are noted elsewhere in this area. In the eastern Atlantic, moderate to fresh winds are noted along and northern of the monsoon trough to 27N. In the northeastern Atlantic, light to gentle N to NE winds are noted. Light to gentle SW winds are noted south of the monsoon trough. Seas range 4 to 7 ft across the area. For the forecast west of 55W, Hurricane Lee will move to near 27.6N 67.7W this evening with maximum sustained winds 95 kt gusts 115 kt, to near 29.6N 68.2W early Thu with maximum sustained winds 90 kt gusts 110 kt, and continue to slowly weaken as it passes WSW of Bermuda near 31.8N 68.2W early Thu evening with maximum sustained winds 85 kt gusts 105 kt and weakening further as it lifts to well N of the area through the weekend. Large swells from Lee will propagate in all directions and dominate the regional waters W of 55W through Fri. $$ AReinhart