000 AXNT20 KNHC 032320 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Sep 3 2021 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... Hurricane Larry is centered near 15.0N 42.0W at 03/2100 UTC or 1020 nm W of the Southernmost Cabo Verde Islands moving WNW at 14 kt. Estimated minimum central pressure is 978 mb. Maximum sustained wind speed is 85 kt with gusts to 105 kt. Satellite imagery continues to depict a somewhat asymmetrical central dense overcast. Numerous moderate to strong convection is noted within 250 nm of the center in the southern semicircle and 200 nm in the northern semicircle. A band of scattered moderate to isolated strong convection is south of the system from 07N to 11N between 40W and 47W. Peak seas are 29 ft with 12 ft seas extending within 270 nm of the center in the northern semicircle, 240 nm in the SE quadrant, and 180 nm in the SW quadrant. Larry will continue moving WNW over the weekend and a turn to the northwest is forecast by early next week. Additional strengthening is forecast during the next few days, and Larry is forecast to become a major hurricane this weekend. 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 at www.hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave has an axis along 28W from 19N southward, moving westward at 15 kt. There is no significant convection associated with this wave. A tropical wave has an axis along 66W from 20N southward, moving westward at 15-20 kt. Scattered moderate to isolated strong convection is noted east of the wave near the Windward Islands, from 10N to 14N between 60W to 65W. Scattered thunderstorms are also near the wave axis across Puerto Rico. A western Caribbean Sea tropical wave has an axis along 81W from 12N southward, moving westward at 15 kt. Scattered moderate convection is noted within 20 nm of the wave S of 11N. ...MONSOON TROUGH/ITCZ... The monsoon trough axis passes through the coast of Senegal near 13N17W to 11N25W. It resumes southwest of Hurricane Larry near 11N42W to 09N48W. The ITCZ extends from 09N48W to 10N57W. Aside from the convection associated with Hurricane Larry and the tropical waves, numerous strong convection is moving off the African coast from 09N to 15N E of 18W. GULF OF MEXICO... At 2100 UTC, stationary front was lingering across the northern Gulf of Mexico from central Florida near 28N83W to south- central Louisiana near 29N92W. Isolated thunderstorms are noted across the northern and central Gulf, N of 26N and from the Florida coast to the Upper Texas coast. Otherwise, high pressure extends across the basin anchored by a 1014 mb high near 25N88W. Light to gentle winds are occurring throughout the Gulf of Mexico with seas 2 to 4 ft. For the forecast, a surface trough moving across the Yucatan Peninsula will move into the southwest Gulf of Mexico by late late Sat or Sun. Unfavorable upper level winds are likely to limit significant development while the system moves NW or N over the western Gulf of Mexico early next week. Elsewhere, a stationary front over the north-central and northeast Gulf will gradually dissipate through early Sun, while weak high pressure dominates much of the remainder of the basin. CARIBBEAN SEA... See the tropical waves section above for details on a convectively active tropical wave that is presently over the eastern Caribbean. A surface trough to the west of the Gulf of Honduras is producing scattered moderate to isolated strong convection from 15N to 21N and W of 82W. Moderate to fresh winds are also noted in the Gulf of Honduras. Otherwise, diurnally driven convection is occurring across most of the Greater Antilles and reaching adjacent waters. Moderate to fresh trades are noted across most of the Caribbean with strong trades near the Colombia coast. Light to gentle winds are noted in the NW and SW Caribbean. For the forecast, Hurricane Larry is well east of the area in the central Atlantic near 15.0N 42.0W 978 mb at 5 PM EDT moving WNW at 14 kt. Maximum sustained winds 85 kt gusts 100 kt. Larry will change little in intensity as it moves well northeast of the Leeward Islands late Mon early Tue, and tropical storm force are possible east of 60W by Sun night and Mon. At a minimum, large swells generated by Hurricane Larry are expected to propagate across the waters east of the Leeward Islands on Sun, likely spreading west of 65W Mon and Mon night. Elsewhere, fresh to occasionally strong trade winds will pulse off Colombia through late Sat. ATLANTIC OCEAN... Please see the Special Features section for details on Hurricane Larry. At 2100 UTC, a cold front extended off the Florida coast from 30N76W to 28N81W. A pre-frontal trough extends south of the front across the northern Bahamas from 29N78W to 25N79W. Scattered moderate convection is noted along and south of the front N of 24N between 72W and 80W. Gentle to moderate NE winds are north of the front with gentle SW winds ahead of the front. Seas range 3 to 6 ft. Towards the central Atlantic, an upper-level low is centered near 25N66W. This is bringing an area of scattered moderate to isolated strong convection from 22N to 31N between 64W to 73W. Another area of numerous strong convection is to the east of the upper low from 23N to 28N between 55W to 62W. Otherwise, high pressure extends across the central and eastern Atlantic anchored by a 1021 mb high near 30N48W. Light to gentle winds are generally occurring in this area with seas 3 to 5 ft. For the forecast east of 65W, Hurricane Larry is well east of the area in the central Atlantic near 15.0N 42.0W 978 mb at 5 PM EDT moving WNW at 14 kt. Maximum sustained winds 85 kt gusts 100 kt. Larry will continue to move WNW through Sun, and will pass well northeast of the Leeward Islands near 19.4N 50.8W Sun afternoon, 20.7N 52.8W Mon morning, and 21.9N 54.5W Mon afternoon. Larry will change little in intensity as it moves more NW thereafter well to the north of Leeward Islands. Large swells generated by Hurricane Larry are expected to propagate across the waters east of the Leeward Islands on Sun, likely spreading west of 65W Mon and Mon night. In the eastern Atlantic, a trough extends to the west of the Canary Islands from 31N22W to 25N28W. Showers are noted along this trough. Otherwise, high pressure extends across the area. Mostly gentle to moderate winds are noted in this region with seas 4 to 7 ft. $$ AReinhart