000 AXNT20 KNHC 061035 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Wed Sep 6 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 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...SPECIAL FEATURES... Tropical Storm Lee is centered near 13.7N 44.6W at 06/0900 UTC or 1100 nm ESE of the Northern Leeward Islands, moving WNW at 12 kt. Estimated minimum central pressure is 997 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Peak seas are up to 14 ft. A band of moderate to isolated strong convection is over the western semicircle with a central dense overcast feature. Continued steady to rapid strengthening is forecast, and Lee is expected to become a hurricane later today and a major hurricane in a couple of days. A west-northwest motion is expected to continue for the next few days with a slight reduction in forward speed. Swells generated by Lee are expected to reach portions of the Lesser Antilles on Friday. These swells are likely to cause life-threatening surf and rip current conditions. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest Lee NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave, with axis along 19W, is producing a large area of disorganized showers and thunderstorms over the far eastern Atlantic between the Cabo Verde Islands and the west coast of Africa. A 1009 low pressure (AL96) is along the wave axis near 11N19W. Environmental conditions appear conducive for some gradual development of this system, and a tropical depression could form later this week or this weekend while the system moves west- northwestward at 10 to 15 mph over the eastern tropical Atlantic. This system is expected to move across the Cabo Verde Islands tonight and Thursday, and interests there should monitor its progress. This system has a low chance of tropical cyclone formation through 48 hours, and a medium chance through 7 days. Please, refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. A tropical wave is over Central America. Its axis is along 86W moving W at 10 to 15 kt. Scattered showers and thunderstorms are along the wave axis affecting parts of Nicaragua and Honduras. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Mauritania near 18N16W and continues to Invest 96L near 11N19W and to 13N30W. The monsoon trough continues W of Tropical Storm Lee from 11N48W to 12N58W. Aside from the convection discussed in the Special Features and Tropical Waves section, scattered moderate convection is noted from 06N to 10N between 22W and 34W. ...GULF OF MEXICO... High pressure over the SE US dominates the Gulf waters producing gentle to moderate E to SE winds. A weak surface trough is over the western Yucatan Peninsula generating a few showers. Scattered showers with embedded thunderstorms are noted over the NE and SE parts of the Gulf region, including the adjacent waters of western Cuba. Seas are generally 1 to 3 ft based on a couple of altimeter passes, except 3 to 4 ft in the Straits of Florida. For the forecast, a weak ridge will dominate the Gulf waters most of the forecast period supporting light to gentle winds and slight seas, with the exception of gentle to moderate winds just W of the Yucatan Peninsula, mainly at night. ...CARIBBEAN SEA... High pressure N of the area combined with the Colombian low supports fresh to strong winds over the south-central Caribbean. Recent scatterometer data confirmed the presence of these winds, reaching 30 kt in the Gulf of Venezuela. Seas are 6 to 8 ft in the south- central Caribbean, with the highest seas near the coast of Colombia. gulf moderate to fresh trade winds in the eastern and central Caribbean. Seas of 3 to 5 ft are elsewhere across the E and central Caribbean. Seas of 1 to 3 ft prevail elsewhere. A surface trough extends across the Windward Passage into western Jamaica. Numerous showers and thunderstorms are along the trough axis that continues NE into the Atlantic waters. A tropical wave is enhancing convection over Nicaragua and Honduras. Patches of low level moisture, embedded in the trade wind flow, are noted elsewhere. For the forecast, moderate to fresh trade winds and moderate seas will continue in the central and eastern Caribbean into the weekend. Gentle to locally moderate winds and slight seas will prevail elsewhere. Tropical Storm Lee is near 13.7N 44.6W at 5 AM EDT, and is moving west-northwest at 12 kt. Maximum sustained winds are 55 kt with gusts to 65 kt, and the minimum central pressure is 997 mb. Lee will strengthen to a hurricane near 14.3N 46.4W this afternoon, move to 15.1N 48.8W Thu morning, 16.0N 51.3W Thu afternoon, 17.0N 53.7W Fri morning, 18.1N 56.2W Fri afternoon, and 19.2N 58.4W Sat morning. Lee is forecast to become a major hurricane by late this week and could bring impacts to the Leeward Islands this weekend. ...ATLANTIC OCEAN... Please read the SPECIAL FEATURES section for details on Tropical Storm Lee forecast to become a hurricane later today and a major hurricane in a couple of days. A surface trough extends from 26N62W to the Windward Passage. Scattered to numerous showers and thunderstorms are associated with the trough that is a reflection of an upper-level trough extending across the western Atlantic. The surface trough will move westward over the next 48-72 hours as the Atlantic high pressure builds westward. Farther east, another surface trough enters the forecast waters near 31N50W and continues S to 22N53W. A few showers are near the trough axis. An upper-level low is spinning 31N42W generating some shower and thunderstorm activity. The remnant low of Katia is near 27.5N33W. This former tropical cyclone is still producing a small cluster of showers and thunderstorms to NE of the center. An area of 8 ft is associated with Katia, affecting roughly the waters from 26N to 29N between 32W and 36W. The remainder of the Atlantic forecast waters is under the influence of weak high pressure centers. Outside of Lee, seas pf 5 to 7 ft dominate most of the waters E of 55W. For the forecast west of 55W, Tropical Storm Lee is near 13.7N 44.6W at 5 AM EDT, and is moving west-northwest at 12 kt. Maximum sustained winds are 55 kt with gusts to 65 kt, and the minimum central pressure is 997 mb. Lee will strengthen to a hurricane near 14.3N 46.4W this afternoon, move to 15.1N 48.8W Thu morning, 16.0N 51.3W Thu afternoon, 17.0N 53.7W Fri morning, 18.1N 56.2W Fri afternoon, and 19.2N 58.4W Sat morning. Lee is forecast to become a major hurricane by late this week and could bring impacts to the Leeward Islands this weekend. $$ GR