000 AXNT20 KNHC 211026 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 626 AM EDT Fri Aug 21 2020 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...SPECIAL FEATURES... Tropical Depression Thirteen is centered near 17.8N 58.5W at 21/0900 UTC or 270 nm E of the Northern Leeward Islands moving WNW at 18 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate isolated strong convection is noted from 14N to 19N between 56W and 60W. Peak seas are currently around 11 ft to the NE of the center. The depression is expected to move near or north of the northern Leeward Islands later today, near or north of the Virgin Islands and Puerto Rico on Sat, and near or north of Hispaniola Sat night. Gradual strengthening is forecast, and the depression is likely to become a tropical storm by the weekend. 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 Depression Fourteen is centered near 15.4N 83.1W at 21/0900 UTC or 30 nm NNE of Cabo Gracias A Dios on the Nicaragua/Honduras border moving WNW at 10 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate convection is noted within 300 nm NE and 120 nm NW quadrants. Peak seas are currently around 10 ft to the NE of the center. The center of the system will move near or just offshore the coasts of northern Nicaragua and northeastern Honduras, including the Bay Islands, today and approach the east coast of the Yucatan Peninsula of Mexico on Sat. The center is then expected to cross the Yucatan Peninsula Sat night and move into the south-central Gulf of Mexico on Sun. Strengthening is forecast during the next couple of days, and the depression is expected to become a tropical storm later today. The system is forecast to be near or at hurricane strength when it reaches the Yucatan Peninsula of Mexico late Sat. Some weakening is expected as it traverses the Yucatan Peninsula Sat night. Afterward, restrengthening is forecast on Sun as it moves offshore and enters the southern Gulf of Mexico. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT4.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT4.shtml for more details. ...TROPICAL WAVES... A tropical wave near the coast of Africa has an axis along 19W south of 18N, moving W at 10 kt. Scattered moderate isolated strong convection is noted from 13N to 18N within 120 nm of the wave axis. This wave is expected to move farther offshore over the far eastern tropical Atlantic on Fri, and it could become a tropical depression within the next few days while it moves west- northwestward at 15 to 20 mph across the eastern tropical Atlantic. Environmental conditions are expected to become less favorable for development early next week. Regardless of development, this system will likely bring gusty winds across portions of the Cabo Verde Islands this weekend, as well as heavy rains that could cause flooding. THis system has a medium chance of tropical cyclone formation during the next five days. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. An Atlantic tropical wave axis nearing the Windward Islands has an axis along 60W south of 20N, moving W at 10-15 kt. Associated convection is described above with T.D. Thirteen. An eastern Caribbean tropical wave has an axis along 68W south of 20N, moving W at 10-15 kt. Scattered moderate convection is noted from 16N to 20N within 90 nm of the wave axis, including the Mona Passage. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Mauritania near 18N16W to 12N21W to 08N29W to 08N39W. The ITCZ extends from 15N54W to the coast of Venezuela near 10N62W. Scattered moderate isolated strong convection is occurring within 150 nm S of the monsoon trough between 24W and 27W, and within 90 nm of the monsoon trough W of 31W. GULF OF MEXICO... Please see the Special Features section for more details on Tropical Depression Thirteen and Tropical Depression Fourteen. A stationary front remains draped along the north-central Gulf Coast this morning. Scattered thunderstorms are noted near this boundary over the coastal waters of southeast Texas and Louisiana. A couple of weak surface troughs extend across the central Gulf, with some isolated thunderstorms from 25N to 27N between 87W and 90W. Gentle winds prevail across the basin, with some moderate winds over the NE Gulf and near the Yucatan peninsula. Seas are 3 ft or less across the offshore waters. T.D. Thirteen will move to 18.1N 60.7W this afternoon, strengthen to a tropical storm near 18.8N 64.0W Sat morning, 19.7N 67.5W Sat afternoon, 20.6N 71.1W Sun morning, 21.8N 74.9W Sun afternoon, and 23.2N 78.5W Mon morning. Thirteen will strengthen to a hurricane over the eastern Gulf near 26.5N 84.0W early Tue. T.D. Fourteen will strengthen to a tropical storm near 16.3N 84.3W this afternoon, move to 17.7N 85.4W Sat morning, 19.2N 86.4W Sat afternoon, inland to 20.7N 87.5W Sun morning, move into the south-central Gulf near 22.5N 88.8W Sun afternoon, and strengthen to a hurricane over the central Gulf near 24.5N 90.2W Mon morning. Fourteen will change little in intensity as it moves to the NW Gulf near 28.1N 93.0W early Tue. CARIBBEAN SEA... Please see the Special Features section for more details on Tropical Depression Fourteen. Overnight scatterometer data shows moderate trades over the south-central Caribbean, with locally fresh winds near the coast of Colombia and in the Gulf of Venezuela. Elsewhere outside of T.D. Fourteen, gentle to moderate winds prevail across the basin. Scattered thunderstorms are noted offshore of western Cuba, as well as from 13N to 15N between 75W and 77W. T.D. Fourteen will strengthen to a tropical storm near 16.3N 84.3W this afternoon, move to 17.7N 85.4W Sat morning, 19.2N 86.4W Sat afternoon, move inland over the Yucatan Peninsula to 20.7N 87.5W Sun morning, then move into the south-central Gulf of Mexico near 22.5N 88.8W Sun afternoon. ATLANTIC OCEAN... Please see the Special Features section for more details on Tropical Depression Thirteen. A subtropical ridge axis extends across the western Atlantic from 1019 mb high pressure centered near 30N51W. The pressure gradient between this high and T.D. Thirteen is producing a broad region of moderate to fresh winds S of 25N between 50W and 60W, with seas of 6-10 ft based on overnight altimeter data. Elsewhere, gentle to moderate winds prevail across much of the remaining Atlantic waters. A stationary front is analyzed over the eastern Atlantic from 32N20W to 23N40W, with moderate to locally fresh winds between the front and the coast of Western Sahara. T.D. Thirteen will move to 18.1N 60.7W this afternoon, strengthen to a tropical storm near 18.8N 64.0W Sat morning, 19.7N 67.5W Sat afternoon, 20.6N 71.1W Sun morning, 21.8N 74.9W Sun afternoon, and 23.2N 78.5W Mon morning. Thirteen will strengthen to a hurricane over the eastern Gulf of Mexico near 26.5N 84.0W early Tue. $$ B Reinhart