000 AXNT20 KNHC 122125 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Aug 13 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 2000 UTC. ...SPECIAL FEATURES... Tropical Depression Fred is centered near 21.3N 75.3W at 12/2100 UTC or 410 nm ESE of Key West Florida moving WNW at 10 kt. Estimated minimum central pressure is 1012 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are currently 9 ft. Convection is currently displaced from the center with scattered moderate noted in a band between 90 nm and 420 nm in the northeast quadrant, between 60 nm and 120 nm in the northwest quadrant, and between 120 nm and 210 nm in the south semicircle. Additional scattered moderate convection is noted from 22N to 26N between 65W and 70W, with isolated to scattered moderate convection from 26N to 29N between 71W and 79W. Fred is forecast to strengthen to a tropical storm near 24.0N 80.6W Sat morning, move to the Gulf of Mexico near 25.2N 81.9W Sat afternoon, move to 26.4N 83.1W Sun morning, and then to 28.1N 84.1W Sun afternoon. Fred will move inland to 31.0N 85.5W Mon afternoon. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT1.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT1.shtml for more details. Satellite-derived wind data from this morning indicated that a small area of low pressure has developed near 14N43W along a tropical wave about 1200 nm east of the Lesser Antilles. However, the low does not quite have a closed circulation, and the associated shower and thunderstorm activity remains disorganized. Scattered moderate and isolated strong convection is noted from 08N to 16N between 43W and 49W. Current winds are 20 to 30 kt. Peak seas are 8 ft. Environmental conditions are expected to become more conducive for additional development, and a tropical depression is likely to form by the weekend while moving generally westward at about 20 kt across the tropical Atlantic. This system has a medium chance of tropical cyclone formation through 48 hours, and a high chance through the next 5 days. This system is expected to reach portions of the Leeward Islands late Sat or early Sun, and interests there should monitor its progress. Please read the latest NHC Tropical Weather Outlook at hurricanes.gov for more details. ...TROPICAL WAVES... Refer to the Special Features section for details on a tropical wave in the Atlantic Ocean along 43W. A tropical wave is in the Atlantic Ocean just offshore of the coast of Africa along 18W south of 20N, moving W at around 15 kt. Scattered moderate and isolated strong convection is noted from 05N to 09N between 13W and 19W. A tropical wave is in the Atlantic Ocean from 23N55W to Suriname/Guyana border at 04N58W, moving W at 15 to 20 kt. Scattered moderate and isolated strong convection is noted from 09N to 14N between 58W and 62W. A tropical wave is in the Caribbean Seas along 78W south of 16N, moving W at around 15 kt. Only isolated moderate convection is noted near the tropical wave. A tropical wave is in the Gulf of Mexico along 93W south of 23N, moving W at 5 to 10 kt. Scattered moderate convection is noted from 22N to 26N between 90W and 94W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near the border of Senegal and Guinea-Bissau from 11N15W to 06N26W to 11N42W. Scattered moderate and isolated strong convection is noted from 08N to 11N between 28W and 33W, and from 04N to 10N between 50W and 55W. ...GULF OF MEXICO... Refer to the Special Features section for details on Tropical Depression Fred. An upper level trough is supporting scattered showers and thunderstorms across the northern Gulf of Mexico, mainly between 84W and 94W. A surface trough is located in the SW Gulf and western Bay of Campeche from near Tampico, Mexico to 18N93W. Isolated showers and thunderstorms are noted near the trough axis. The rest of the basin enjoys fairly tranquil weather conditions. Mainly gentle easterly winds prevail across the basin, locally moderate through the Straits of Florida. Seas are mainly 3 ft or less, locally higher near any convection. For the forecast, Fred is expected to move across the eastern Straits of Florida and the far eastern Gulf of Mexico as a tropical storm by Fri night, and move northward along the far eastern Gulf into early next week. Meanwhile, moderate to fresh E winds will pulse off the northwest Yucatan Peninsula into the Bay of Campeche tonight in association with a trough that forms late in the day. Elsewhere, gentle to moderate winds and slight seas will persist through the period. ...CARIBBEAN SEA... Refer to the Special Features section for details on Tropical Depression Fred. Aside from the convection affecting Hispaniola, Jamaica and the surrounding waters due to Tropical Depression Fred, fairly tranquil weather conditions prevail across the Caribbean Sea, except for isolated showers and thunderstorms in the SW Caribbean Sea south of 11N. Moderate to fresh trades are found east of 76W with seas of 4 to 6 ft. Gentle to moderate trades prevail across the rest of the basin, along with seas of 2 to 4 ft. For the forecast, Fred will continue moving away from the Caribbean and have no impact on the basin. Fresh to locally strong winds will persist across most the eastern and central Caribbean through Fri, becoming light to gentle during the weekend. Light to gentle breezes and slight seas will persist elsewhere. Looking ahead, a fairly strong tropical wave will move into the Windward Islands by Sat night, and into the north central Caribbean by Mon. Gusty winds with showers can be expected. ...ATLANTIC OCEAN... Refer to the Special Features section for details on Tropical Depression Fred and an area of low pressure in the central Atlantic near 14N43W. A surface trough in the SW N Atlantic extends from 31N71W to 22N75W. Nearby convection is described in the Special Features section. High pressure dominates elsewhere across the Atlantic waters with fairly tranquil weather conditions. Moderate to fresh easterlies and seas of 4 to 7 ft are present S of 24N, while mainly gentle to moderate easterlies and seas of 3 to 6 ft seas prevail in the rest of the basin. For the forecast west of 65W, Fred will move to 22.0N 77.0W Fri morning, 23.0N 79.0W Fri afternoon, and will strengthen to a tropical storm near 24.0N 80.6W Sat morning. Fred will cross the eastern Straits of Florida and into the far southeast Gulf of Mexico by Fri night. Looking ahead, a fairly strong tropical wave will move into the Windward Islands by Sat night, and into the north central Caribbean by Mon. Gusty winds with showers can be expected. $$ Lewitsky