000 AXNT20 KNHC 050952 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sun Sep 5 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 0600 UTC surface analysis and satellite imagery through 0930 UTC. ...SPECIAL FEATURES... Category Three Hurricane Larry is centered near 18.8N 49.0W at 05/0900 UTC moving NW at 12 kt. Estimated minimum central pressure is 958 mb. Maximum sustained wind speed is 105 kt with gusts to 130 kt. The eye diameter is 45 nm on IR satellite imagery. Numerous moderate to strong convection is noted within 180 nm of the center all quadrants, except 120 nm in the SW quadrant. Seas of 12 ft or higher extend within 300 nm in the N semicircle and 270 nm in the S semicircle, with seas as high as 43 ft. Hurricane Larry is expected to continue to move NW through Tue, gradually slowing in forward speed. Little change in strength is forecast during the next few days, although fluctuations in intensity are possible. Larry is expected to remain a major hurricane into Thu. Swell generated by Larry are expected to reach the Lesser Antilles today, and will spread westward to portions of the Greater Antilles, the Bahamas, and Bermuda Monday and Tuesday. Significant swells will likely reach the east coast of the United States and Atlantic Canada around midweek. 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 east Atlantic tropical wave has an axis along 20W from 03N to 20N, moving W around 10 kt. Scattered moderate convection is noted from 06N to 14N between 14W and 20W. An Atlantic Ocean tropical wave has an axis along 37W from 05N to 19N, moving W at 10 kt. The wave is situated at the leading edge of a Saharan dust plume. As a result of the dry Saharan air, no significant convection is noted with the wave at this time. A Caribbean Sea tropical wave has an axis along 76W, stretching from eastern Cuba to NW Colombia, moving W at 10 to 15 kt. Scattered moderate convection is noted in and near the Windward Passage as well as northern Colombia. Fresh E winds are occurring E of the wave axis in the southern Caribbean. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of southern Mauritania near 17N16W to 06N27W. The ITCZ is from 06N27W to 05N34W, then continues W of a tropical wave from 05N38W to the coast of Venezuela near 10N61W. Aside from the convection mentioned in the Tropical Waves section above, scattered moderate convection is noted within 150 nm either side of the ITCZ between 38W and 46W. GULF OF MEXICO... A previously stationary front is weakening and beginning to lift north early this morning, extending from the Florida Big Bend to the coast of Mississippi. No convection is occurring along this boundary. A pair of 1015 mb high pressure centers are located near 27N92W and 25N83W, and are the dominant weather features in the Gulf of Mexico this morning. A surface trough stationary along the west coast of the Yucatan Peninsula is inducing scattered moderate convection in the extreme eastern Bay of Campeche, while another trough along the western coast of the Bay of Campeche is producing similar convection in that vicinity. More numerous and stronger convection is located well inland over Guatemala. Light to gentle winds and slight seas encompass the basin, except over in the SW Gulf, where moderate E winds are occurring. For the forecast, the surface trough over the Yucatan Peninsula, combined with a weak upper level low, will continue to produce locally heavy rainfall today. The trough is forecast to move NW into the SW Gulf of Mexico later today, then move slowly N or NE over the western or central Gulf of Mexico. Upper- level winds are forecast to be only somewhat conducive for tropical formation, but some slow development is possible through mid week. There is a low chance of tropical formation over the next 5 days. Elsewhere, a weakening front over the NE Gulf will dissipate today, while high pressure dominates much of the remainder of the basin. CARIBBEAN SEA... See the Tropical Waves section above for details on a tropical wave in the central Caribbean. An upper level trough N of the area is inducing scattered moderate convection N of 19N between 75W and 83W, mainly between Jamaica, Cuba, and the Cayman Islands. Otherwise, significant convection is not occurring in the basin. Moderate to fresh E winds are ongoing over most of the central and eastern Caribbean as well as in the Gulf of Honduras, with gentle to moderate winds elsewhere. Seas are 4 to 6 ft, except 2 to 4 ft in the NW Caribbean. For the forecast, Major Hurricane Larry will remain well N and E of the area, then move N and away from the area by midweek. Associated rough seas are entering the region this morning, and will reach the Leeward Islands and Atlantic entrances by early Mon, then subside mid week. Elsewhere, gentle to moderate trade winds will persist, pulsing to fresh winds off Colombia mainly at night. ATLANTIC OCEAN... See Special Features section above for details on Major Hurricane Larry. A weak stationary front extends from 32N72W to near Cape Canaveral, Florida. A 1013 mb low pressure center is located along this boundary near 28N78W. Scattered moderate convection is noted E of these features, N of 23N and W of 63W. Otherwise, high pressure dominates most of the basin, outside of the influence of Hurricane Larry. This is leading to gentle to moderate winds across the basin. Farther to the east, some locally fresh NE to E trades are occurring around the Cabo Verde Islands. For the forecast, Major Hurricane Larry will move to 19.9N 50.4W this afternoon, 21.2N 52.1W Mon morning, 22.4N 53.6W Mon afternoon, 23.6N 55.0W Tue morning, 25.0N 56.4W Tue afternoon, and 26.5N 57.8W Wed morning. Larry will change little in intensity as it moves SE of Bermuda early Thu. Large swell and rough seas generated by Larry will continue to propagate across waters north of the Leeward Islands spread W of 65W by early Mon, the perhaps reach 70W by mid week. $$ KONARIK