000 AXNT20 KNHC 191057 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Thu Aug 19 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 1150 UTC. ...SPECIAL FEATURES... Hurricane Grace is centered near 20.1N 87.5W at 19/0945 UTC or 10 nm S of Tulum Mexico moving W at 15 kt. Estimated minimum central pressure is 986 mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt. Peak seas are 28 ft. Scattered moderate isolated strong convection is from 17N to 21N between 83W and 87W. Grace made landfall along the eastern Yucatan Peninsula near Tulum, is expected to move across the Yucatan Peninsula today, and move over the southwest Gulf of Mexico late tonight through Friday. Grace is expected to weaken as it crosses Yucatan, but re-intensification is expected when the center reaches the Gulf of Mexico. 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 centered near 29.5N 69.5W at 19/0900 UTC or 460 nm SE of Cape Hatteras North Carolina moving W at 8 kt. Estimated minimum central pressure is 995 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Peak seas are 23 ft. Numerous moderate convection is from 27N to 31N between 67W and 73W. On the forecast track, the center of Henri will remain well offshore the east coast of the United States over the next couple of days but could approach southeastern New England on Sunday. Some strengthening is forecast during the next few days, and Henri is expected to become a hurricane by Friday. 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... A tropical wave extends from 02N to 19N with axis near 26W, moving W at 10-15 kt. Scattered moderate convection is from 07N to 15N between 20W and 31W. A tropical wave extends from 03N to 19N with axis near 37W, moving W at 10-15 kt. Scattered moderate convection is from 04N to 13N between 32W and 47W. A tropical wave extends from 06N to 20N with axis near 56W, moving W at around 15 kt. Scattered showers and tstms associated with it are affecting the Lesser Antilles. A tropical wave extends S of 20N with axis near 69W, moving W at around 15 kt. No significant deep convection is currently associated with this wave. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from Senegal near 15N16W to 12N30W and to 11N42W. The ITCZ then extends from 11N43W to 07N53W. Moderate scattered convection is noted south of the monsoon trough and ITCZ to 03N and between the coast of Africa to 45W. ...GULF OF MEXICO... Refer to the Special Features section above for details on Hurricane Grace. The Gulf of Mexico is located in the SW periphery of the broad subtropical ridge over the Atlantic. This is resulting in fairly tranquil weather conditions, outside of the outer rainbands of Hurricane Grace and diminishing evening thunderstorms exiting the Yucatan peninsula into the E Bay of Campeche. Moderate to fresh easterly breezes prevail across the central, SE and W Gulf of Mexico, including the Bay of Campeche, and seas of 3-6 ft. Gentle to moderate SE winds and seas of 1-3 ft are prevalent in the NE Gulf. For the forecast, Hurricane Grace near 19.8N 85.6W 988 mb at 11 PM EDT moving W at 16 kt. Maximum sustained winds 70 kt gusts 85 kt. Grace will move inland to 20.3N 88.1W Thu morning, weaken to a tropical storm near 20.6N 91.4W Thu evening, strengthen to a hurricane near 20.7N 94.0W Fri morning, 20.5N 96.1W Fri evening, move inland and weaken to a tropical storm near 20.0N 98.8W Sat morning, and move inland and weaken to a tropical depression near 19.7N 101.6W Sat evening. Grace will dissipate late Sun. Winds and seas will begin to increase across the southeastern Gulf ahead of Grace tonight. These conditions will shift to west of 90W Thu through late Fri night. ...CARIBBEAN SEA... Refer to the Special Features section above for details on Hurricane Grace. Outside of the wind field of Hurricane Grace, a recent scatterometer satellite pass depict fresh to strong trades across the central and E Caribbean Sea, with the strongest winds located in the south-central Caribbean, off the NW coast of Colombia. Gentle to moderate trades are noted in the SW Caribbean and Gulf of Honduras. Seas are 6-8 ft in the central Caribbean, 4-6 ft in the E Caribbean and 2-4 ft in the rest of the basin. For the forecast, Hurricane Grace near 19.8N 85.6W 988 mb at 11 PM EDT moving W at 16 kt. Maximum sustained winds 70 kt gusts 85 kt. Grace will move inland to 20.3N 88.1W Thu morning, weaken to a tropical storm near 20.6N 91.4W Thu evening, strengthen to a hurricane near 20.7N 94.0W Fri morning, 20.5N 96.1W Fri evening, move inland and weaken to a tropical storm near 20.0N 98.8W Sat morning, and move inland and weaken to a tropical depression near 19.7N 101.6W Sat evening. Grace will dissipate late Sun. Elsewhere, fresh to strong trades will be over the central Caribbean through early Thu. ...ATLANTIC OCEAN... Please refer to the sections above for details on Tropical Storm Henri and on the tropical waves moving across the basin. The 1026 mb Azores-Bermuda subtropical ridge remains the dominant feature in the tropical Atlantic outside of Tropical Storm Henri. This is allowing for fairly tranquil weather conditions across the basin. However, a few showers are noted east of the Lesser Antilles from 13N to 16N and between 56W and 60W. The strong high pressure system and lower pressures over NW Africa result in a tight pressure gradient over the NE Atlantic. Recent scatterometer satellite data show strong to near gale-force N-NE winds surrounding the Canary Islands and off the coasts of Morocco and Western Sahara. Seas in this area are in the 5-8 ft range. An area of fresh to strong NE winds is noted from 19N to 29N and between 35W and 50W, with seas of 5-8 ft. Winds in the rest of the basin are moderate to fresh with seas in the 2-5 ft range. For the forecast west of 65W, Tropical Storm Henri near 29.8N 68.5W 995 mb at 11 PM EDT moving W at 8 kt. Maximum sustained winds 60 kt gusts 75 kt. Henri will move to 29.8N 69.9W Thu morning, 30.0N 71.8W Thu evening, strengthen to a hurricane near 30.7N 72.7W Fri morning, 32.3N 72.8W Fri evening, 34.4N 71.8W Sat morning, and 36.9N 70.7W Sat evening. Henri will change little in intensity as it moves near 40.4N 69.4W late Sun. Elsewhere, high pressure will persist across the forecast waters through the period. Fresh east to southeast winds over the far southwest part of the area will shift W to the Straits of Florida tonight. $$ Ramos