000 AXNT20 KNHC 092338 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Sep 10 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 2345 UTC. ...SPECIAL FEATURES... Hurricane Larry is centered near 33.9N 62.2W at 09/2100 UTC or 160 nm NE of Bermuda moving NNW at 17 kt. Estimated minimum central pressure is 966 mb. Maximum sustained wind speed is 80 kt with gusts to 100 kt. Seas are peaking near 40 ft about 400 nm in the NE quadrant and 280 nm se quadrant. Numerous moderate to strong convection is noted in 180 nm NE quadrant and scattered moderate convection is seen about 100 nm in the SW quadrant. On the forecast track, the center of Larry will continue to move away from Bermuda tonight, and move near or over southeastern Newfoundland Friday night or early Saturday morning. Gradual weakening is forecast to begin on Friday, but Larry is expected to remain a hurricane until it passes Newfoundland. Larry should become an extratropical cyclone on Saturday, then weaken further while it passes southeast of Greenland Sunday night. Larry is expected to be absorbed by a larger extratropical low east of Greenland by Monday. 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 Depression Mindy is centered near 32.0N 78.3W at 09/2100 UTC or 100 nm ESE of Charleston South Carolina moving ENE at 20 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Satellite imagery shows scattered moderate convection is noted NNE of the center, along the coast of S and N Carolinas. Seas are from 7 to 8 ft off the Georgia and NE Florida coasts. The depression is moving toward the east-northeast and this motion is expected to continue through tonight, followed by a decrease in forward speed on Friday. Gradual weakening is expected, and Mindy is forecast to become a remnant low on Friday. Please read the latest Offshore Zones Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAOFFNT4.shtml and the latest NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... An Atlantic tropical wave is near 31W from 20N southward and moving W near 15 kt. Scattered showers are noted in the vicinity of the wave axis. Another Atlantic tropical wave is along 46W from 19N southward and moving W at 10 to 15 kt. A 1014 mb low is observed with this wave near 12N43W. Scattered moderate convection is seen from 07N to 17N between 41W and 46W. A Caribbean tropical wave is near 69W from 15N southward across N Venezuela and SE Colombia, and moving W near 15 kt. The wave is mainly monitored through the 700 mb trough diagnostics and the 700 mb rawindsonde observations. Scattered showers and isolated thunderstorms are occurring over S Venezuela. ...MONSOON TROUGH/ITCZ... A monsoon trough passes through the Gambia coast near 13N16W to 12N31W. The ITCZ continues from 12N31W to 14N41W, then resumes from 08N44W. Scattered moderate to isolated strong convection is noted south of the monsoon trough along the coast of Africa from Guinea-Bissau to the coast of Sierra Leon. Scattered moderate convection is noted 08N to 18N between 39W to 41W and between 44W to 47W. ...GULF OF MEXICO... A surface trough runs northeastward from 22N95W to 26N94W across the W Gulf. Aided by a mid to upper-level trough in the vicinity, scattered showers and thunderstorms are flaring up over much of the Gulf, except waters off the N Mexico coast. Moderate to locally fresh winds and seas at 3 to 5 ft are evident at the NE Gulf near the Florida Big Bend coast. Light to gentle winds and seas at 2 to 3 ft prevail across the rest of the Gulf. For the forecast, Tropical Depression Mindy is over the Atlantic waters E of the coast of Georgia. The northern portion of a tropical wave over northeastern Honduras and the western Caribbean Sea is forecast to emerge over the southern Bay of Campeche on Saturday. Environmental conditions are expected to be conducive to support some gradual development of the system before it moves over mainland Mexico early next week. This could bring an increase in winds and seas across the Gulf waters during the upcoming weekend. ...CARIBBEAN SEA... Convergent trade winds are coupling with divergent flow aloft to trigger scattered showers and thunderstorms over the NW basin, including the coast of the Yucatan Peninsula and Honduras. The E end of the E Pacific monsoon trough is producing similar conditions at the SW basin, including the coast of Nicaragua, Costa Rica and Panama. Due to weaker pressure gradient between the mid-Atlantic ridge and the lower pressure over Colombia, mainly gentle to moderate trades and seas at 3 to 5 ft are present across much of the basin. Locally fresh winds and seas up to 6 ft are possible in stronger thunderstorms. For the forecast, as Larry continues to move farther north, the Atlantic ridge will build westward N of the Caribbean Sea bringing an increase in the trade wind flow tonight into the weekend. Locally strong winds are possible offshore Colombia and in the Gulf of Venezuela, mainly during the nights. ...ATLANTIC OCEAN... Please see the Special Features section above for details on Major Hurricane Larry near Bermuda and Tropical Depression Mindy just off the coast of S Carolina. Convergent moderate SW to W winds SW and S of Tropical Depression Mindy are causing scattered showers and isolated thunderstorms across N and central Florida, and over NW and central Bahamas. A pronounced upper-level trough S of the Azores near 30N29W is producing scattered moderate convection N of 25N between 20W and 30W. Refer to the Tropical Waves and Monsoon Trough/ITCZ sections for additional convection across the Atlantic Basin. Larger swells traveling farther away from Larry are generating seas of 5 to 8 ft N of 23N between 69W and the Florida-Georgia coast, including the Bahamas. Similar seas are also found from 21N to 25N between 56W and 69W, and N of 24N between 48W and 53W. For the remainder of the basin, seas range from 4 to 6 ft. Outside the influence of Larry, light to gentle winds are present from the N coast of the Greater Antilles to beyond 31N between 67W and 77W. Gentle to moderate NE trades are dominating N of 10N between the African coast and 53W/Windward Islands. Light to gentle S to SW winds prevail S of 10N. For the forecast, Tropical Depression Mindy near 32.0N 78.3W 1005 mb at 5 PM EDT moving ENE at 20 kt. Maximum sustained winds 30 kt gusts 40 kt. Mindy will move to 32.9N 74.9W Fri morning, become post- tropical and move to 33.8N 71.2W Fri afternoon, and dissipate Sat morning. Mindy is causing a brief period of fresh to strong SW to W winds N of 29N and W of 78W. Swells generated by Hurricane Larry will continue to propagate across the waters E of the Bahamas tonight and Fri. Seas will then subside into the weekend. $$ Torres