000 AXNT20 KNHC 210554 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sun Aug 21 2022 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 0500 UTC. ...SPECIAL FEATURES... Potential Tropical Cyclone Four is over land. It is centered near 25.3N 97.9W at 21/0300 UTC or 50 nm SW of the mouth of The Rio Grande river and moving NW at 11 kt. Estimated minimum central pressure is 1010 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. This system is expected to move across northeastern Mexico through tonight then dissipate on Sunday. Scattered showers with fresh to locally strong southerly winds and 6 to 8 ft seas are present just south of Brownsville, Texas. Seas and surf will gradually subside tonight but dangerous rip currents will linger along the coast through Sunday. This system can still bring squalls with locally heavy showers and strong thunderstorms to northeastern Mexico tonight, 1 to 3 inches of rain are possible. This can cause flash flooding in low- lying areas and valleys. Please consult products from your local weather forecast office. Please, read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Potential Tropical Cyclone Four NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave is near 22W from 22N southward through a 1010 mb low over the southeastern Cabo Verde Islands at 15N22W, and moving west at 10 to 15 kt. Scattered moderate convection is seen from 10N to 18N between 20W and 26W. This wave will continue to move west to west-northwest across the eastern and central Atlantic through midweek, and has a low chance of tropical cyclone development for the next five days. A central Atlantic tropical wave is near 41W from 20N southward, and moving west at 15 to 20 kt. Scattered showers are found from 05N to 08N between 39W and 46W. A central Caribbean tropical wave is near 72W from 23N southward across the southeast Bahamas and Haiti to near the Colombia- Venezuela border, and moving west at 10 to 15 kt. Scattered showers and isolated thunderstorms are present near Haiti, while numerous heavy showers and scattered strong thunderstorms are occurring over northern Colombia and northwestern Venezuela, and adjacent waters. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic along the coast just south of the Sahara-Mauritania border, passing through the aforementioned 1010 mb low at 15N22W to 08N46W. An ITCZ continues from 08N46W to just north of Suriname at 07N56W. Aside from the convection related to the tropical waves, scattered moderate convection is evident up to 130 nm north and 230 nm south of the monsoon trough. Similar conditions are also present up to 90 nm along either side of the ITCZ. The eastern end of the East Pacific monsoon trough is triggering scattered showers and isolated thunderstorms along the coast of Panama and nearby Caribbean waters. ...GULF OF MEXICO... Please see the SPECIAL FEATURES section for more details on Potential Tropical Cyclone Four. A surface trough reaching from southwest to northeast Florida is producing scattered showers and isolated thunderstorms off the central Florida coast. Convergent moist surface flow is coupling with divergent winds at mid levels to trigger widely scattered showers and isolated thunderstorms over the north-central Gulf, eastern Bay of Campeche and Yucatan Channel. A surface ridge extends southwestward from a 1019 mb high near the Mississippi-Alabama border to just north of Tampico, Mexico. Light to gentle winds and seas at 1 to 2 ft are found across the northeastern and east-central Gulf. Gentle to moderate E to SE winds and 2 to 4 ft seas exist at the southeastern and north- central Gulf. Outside the influence of Potential Tropical Cyclone Four, moderate with locally fresh ENE to SE winds and seas of 4 to 6 ft prevail for the rest of the Gulf, including the Bay of Campeche. For the forecast, Potential Tropical Cyclone Four has moved inland over northeastern Mexico this evening. Maximum seas of about 10 ft just south of Brownsville, Texas will subside to between 6 and 8 ft by early Sun morning. Occasional squalls associated with this system will continue over the far western Gulf through late tonight. Conditions will improve by early Sun morning. Weak ridging will prevail over the Gulf early next week, leading to gentle to moderate winds. ...CARIBBEAN SEA... Aided by an upper-level trough across the northwest and north- central basin, convergent trades are causing scattered showers and isolated thunderstorms over the Gulf of Honduras, south of Cuba, Puerto Rico and the Virgin Islands. Refer to the Tropical Waves section for additional weather in the basin. A 1023 mb Bermuda High is sustaining a NE to E trade-wind regime for the entire basin. Fresh to locally strong ENE winds and 5 to 7 ft seas are found near the Windward Passage and just south of central Cuba. Moderate to fresh NE to ENE winds and seas of 4 to 6 ft are present over the central and eastern basin, and the Gulf of Honduras. Gentle to moderate ENE to E winds and seas at 2 to 4 ft prevail for the remainder of the basin. For the forecast, the Bermuda High along with the passage of a tropical wave currently over the central Caribbean will continue to support moderate to fresh trade winds in the eastern and central Caribbean through tonight. Fresh to locally strong NE winds are expected across the Windward Passage tonight and Sun night. The high will weaken Sun night through Tue, diminishing the winds across the region to gentle to moderate. ...ATLANTIC OCEAN... An upper-level trough reaches southwestward from a low southeast of Bermuda near 24N55W to just east of the Windward Islands. These features are triggering scattered showers and isolated thunderstorms north of 23N between 51W and 63W, and near and just east of the Lesser Antilles. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections for additional weather in the Atlantic Basin. The Bermuda High is supporting light to gentle winds and seas of 2 to 4 ft north of 27N between 45W and the Georgia-Florida coast. Farther south, gentle to moderate NE trades and seas at 3 to 5 ft are noted from 10N to 27N between 45W and the Bahamas/Lesser Antilles. The 1027 mb Azores High is sustaining NNE to NE gentle to moderate trades and 5 to 7 ft seas north of 17N between the African coast and 45W, including near the Canary Islands. Gentle to moderate monsoonal and southerly winds and 5 to 8 ft seas in southerly swell prevail for the rest of the Atlantic Basin. For the forecast W of 55W, the subtropical ridge extends from Bermuda to central Florida. The ridge will change little through Sun night, supporting moderate to fresh easterly winds south of 25N through the remainder of this weekend. Fresh to locally strong winds will pulse north of Hispaniola and the approaches of the Windward Passage tonight and Sun night. A weak surface trough will move westward from 65W to 75W on Mon. The trough will weaken the ridge, thus diminishing winds to between gentle and moderate. $$ Chan