000 AXNT20 KNHC 190602 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 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 0550 UTC. ...SPECIAL FEATURES... Hurricane Grace is centered near 19.9N 86.4W at 19/0600 UTC or 50 nm ESE of Tulum Mexico moving W at 16 kt. Estimated minimum central pressure is 986 mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt. Numerous moderate and scattered strong convection is noted from 16N to 22N and between 81W to 88W. Peak seas are currently near 30 ft near the center. A general westward to west-northwestward motion is expected through Friday, followed by a general westward to west-southwestward motion. On the forecast track, Grace is expected to make landfall in the eastern Yucatan Peninsula during the next six hours, move across the Yucatan Peninsula today, and move over the southwest Gulf of Mexico late tonight through Friday. Some strengthening is forecast before landfall on the Yucatan Peninsula. Grace is expected to weaken as it crosses Yucatan, but re-intensification is anticipated when the center reaches the Gulf of Mexico. Seas up to 30 ft will continue near the center in the NW Caribbean until the hurricane makes landfall in Yucatan and then redevelop to 30 ft in the SW Gulf of Mexico on Friday. 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 29.8N 68.5W at 19/0300 UTC or 245 nm SW of Bermuda 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 currently up to 20 ft near the center. Numerous moderate and scattered strong convection is noted from 27N to 31N and between 65W to 70W. A sharp turn to the north is expected on Friday with a general northward motion continuing into the weekend. Little change is strength is forecast during the next day or so, but Henri is expected to become a hurricane on Friday. Peak seas should continue near 20 ft through Friday morning, before diminishing in our waters as Henri moves northward. 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 25W, south of 19N, and it is moving W at 10-15 kt. Scattered moderate convection is noted along its wave axis from 09N to 13N. A second Atlantic tropical wave has its axis along 35W, south of 19N, and it is moving W at 10-15 kt. Scattered moderate convection is observed along its wave axis from 07N to 13N. A third Atlantic tropical wave has its axis along 54W, south of 20N, and it is moving W at around 15 kt. No significant deep convection is currently associated with this wave. A Caribbean tropical wave has its axis along 67W, south of 21N, and it is 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. $$ DELGADO