000 AXNT20 KNHC 210605 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sat Aug 21 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 0000 UTC surface analysis and satellite imagery through 0450 UTC. ...SPECIAL FEATURES... Hurricane Grace is making landfall south of Tuxpan, Mexico. As of 0600 UTC, the hurricane is centered near 20.6N 97.2W or about 25 nm S of Tuxpan, Mexico. Greta is moving W at 9 kt and this general motion is expected to continue through this evening. Maximum sustained wind speed is 110 kt with gusts to 120 kt. Peak seas are currently 37 ft near the center. Estimated minimum central pressure is 962 mb. An eye is now visible in the latest satellite imagery. Numerous moderate to strong convection is noted across the SW Gulf south of 23N, including the W and central Bay of Campeche. On the forecast track, the center of Grace is forecast to farther inland over mainland Mexico today. Rapid weakening is expected as Grace moves inland over the mountains of central Mexico later today. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT2.shtml and Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT2.shtml for more details. Tropical Storm Henri is forecast to become a hurricane today. As of 0600 UTC, it is centered near 32.4N 73.4W at or 200 nm SSE of Cape Hatteras, North Carolina, moving N at 8 kt. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Peak seas are currently 25 ft near the center. Estimated minimum central pressure is 994 mb. Numerous moderate to isolated strong convection is noted from 28N to 34N and between 71W and 75W. A northward to north-northeastward motion is expected today, with a turn toward the north-northwest expected late today or tonight. On the forecast track, Henri is expected to make landfall in Long Island or southern New England late Saturday night or on Sunday. Strengthening is forecast during the next 24 hours, and be at or near hurricane strength when it makes landfall in Long Island or southern New England. Moderate northeast swell from Henri will impact coastal areas from central Florida to Georgia and the Carolinas tonight through Sat. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT3.shtml and Forecast/Advisory at https://www.nhc.noaa.gov/text/MIATCMAT3.shtml for more details. ...TROPICAL WAVES... An Atlantic tropical wave has its axis along 21W, south of 20N, and it is moving W at 10-15 kt. Scattered moderate convection is noted from 10N to 14N and between 20W and 25W. Another Atlantic tropical wave has its axis along 35W, south of 21N, and it is moving W at around 15 kt. Scattered moderate convection is observed from 05N to 13N and between 30W and 39W. A third Atlantic tropical wave has its axis along 47W, south of 21N, and it is moving W at around 15 kt. Scattered moderate convection is present from 06N to 12N and between 42W and 54W. A Caribbean tropical wave has its axis along 67W, south of 21N, extending from near Puerto Rico southward to Venezuela, and it is moving W at around 15 kt. The wave is enhancing the formation of a few showers and isolated thunderstorms over Venezuela. Another Caribbean tropical wave has its axis along 77W, south of 20N, extending from E Cuba southward to N Colombia, and it is moving W near 10 kt. Scattered moderate convection is noted ahead of the wave axis to the coast of Nicaragua from 11N to 15N. ...MONSOON TROUGH/ITCZ... A monsoon trough extends from the coast of Mauritania near 19N17W to 13N37W and to 11N50W. The ITCZ then continues from 11N51W to the coast of NE Venezuela near 10N61W. Scattered moderate convection is present near to 200 nm south of the ITCZ between 50W and 60W. ...GULF OF MEXICO... Refer to the Special Features section above for details on Hurricane Grace. Hurricane Grace is the main weather feature dominating the Gulf of Mexico. A weak surface ridge is positioned over the NE Gulf, allowing for light to gentle anticyclonic winds across the E and north-central Gulf with seas of 1-3 ft. Moderate to fresh E-SE winds are found in the periphery of Grace in the NW and south- central Gulf. Seas in the area are in the 6-12 ft range. For the forecast, Grace will make landfall near 20.3N 97.9W Sat morning, move inland and weaken to a tropical storm near 20.0N 100.9W Sat evening, and dissipate Sun morning. High pressure will build in the wake of Grace and prevail through early next week. ...CARIBBEAN SEA... The outer rainbands of Hurricane Grace are enhancing the formation of showers and thunderstorms over Central America. Most of the activity is inland or in the E Pacific, however, a few showers and isolated thunderstorms are affecting the W Caribbean coast of Guatemala and S Belize. Scattered moderate convection is also noted south of Hispaniola from 14N to 17N and between 71W and 74W. The rest of the basin enjoys fairly tranquil weather conditions. Moderate to locally fresh trades are found in the Bay of Honduras and north-central Caribbean, with seas of 4-6 ft. Gentle to moderate trades and seas of 2-4 ft prevail elsewhere in the basin. For the forecast, moderate to fresh trade winds will dominate, except localized pulses of strong winds are possible in the Gulf of Honduras through Sat night. Early next week, fresh to strong winds will develop over the central Caribbean. ...ATLANTIC OCEAN... Refer to the Special Features section above for details on Tropical Storm Henri. ALso, please read the Tropical Waves and Monsoon Trough/ITCZ sections for additional convection across the Atlantic Basin. The tropical Atlantic remains under the dominion of an expansive 1023 mb Azores-Bermuda subtropical ridge. The reliable easterlies are carrying an outbreak of dry and dusty Saharan air across the basin, resulting in fairly tranquil weather conditions outside of the deep tropics and the outer rainbands of Tropical Storm Henri. A recent scatterometer satellite data show fresh to strong winds in the periphery of Henri, roughly from 28N to 30N and between 68W and 76W. Seas in the area are 6-12 ft. Moderate to fresh winds are found from 13N to 27N and between 35W to the E Bahamas. Seas in this region are in the 5-7 ft range. Gentle to moderate trades and seas of 4-6 ft are found elsewhere in the basin. For the forecast west of 55W, Henri will strengthen to a hurricane as it continues north of the area to near 34.3N 72.8W Sat morning, and moving off the coast of the Mid-Atlantic U.S. Otherwise, moderate to fresh E to SE winds will prevail E and across the Bahamas through Mon, except for fresh to possibly locally strong winds at night north of Hispaniola and the approaches to the Windward Passage. A tropical wave will move across the area by mid-week with fresh to strong winds ahead of it. $$ DELGADO