874 AXNT20 KNHC 201812 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Tue Jun 20 2023 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Tropical Storm Bret: Tropical Storm Bret is centered near 11.9N 47W at 20/1500 UTC or 945 nm E of the Southern Windward Islands and moving W at 18 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Seas 12 to 14 ft extend up to 80 nm in the N semicircle with peak seas of 15 ft near the center. Seas of 8 to 11 ft extend northward up to 280 nm from the center. Moderate scattered convection can be seen up to 230 nm SW and E of the center. On the forecast track, Bret should be approaching the Lesser Antilles, possible the Windward Islands around Thu as at moderate tropical storm strength. Bret is forecast to slowly weaken after crossing the Lesser Antilles into the Caribbean Sea Friday and Saturday. Regardless of its strength, it will bring a risk of flooding from heavy rainfall, strong winds, and dangerous storm surge and waves to the Windward Islands. Given the larger than usual uncertainty in the track forecast, it is too early to specify the location and magnitude of where these hazards could occur. However, everyone in the Lesser Antilles, Puerto Rico, and the Virgin Islands should closely monitor updates to the forecast for Bret and have their hurricane plan in place. Please read the latest HIGH SEAS FORECAST issued by National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest T.S. Bret Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Invest Area (AL93): A tropical wave in the Eastern Atlantic near 32W from 03N to 14N is moving west around 15 kt. A 1011 mb low pressure is analyzed along the wave axis near 9N32W. Winds are currently fresh to locally strong north of the low-pressure center, generating 5 to 7 ft seas. Widely scattered moderate convection is observed from 07N to 10N between 33W and 38W. Environmental conditions appear favorable for further development of this system, and a tropical depression will likely form within a couple of days while the system moves westward at 10 to 15 kt across the central tropical Atlantic. There is high probability of formation through the next 2 to 7 days. Please refer to the latest Tropical Weather Outlook at www.hurricanes.gov, for more details. ...TROPICAL WAVES... A western Atlantic tropical wave is just east of Windward Islands near 57W from 16N southward across the Guyana-Suriname border, and moving west at 15 to 20 kt. Widely scattered showers and isolated thunderstorms are found from 09N to 16N between 52W and 58W. A Caribbean tropical wave is near 79W from 14N southward across Panama into the East Pacific and moving west at 15 to 20 kt. Isolated thunderstorms are seen near the coast of Costa Rica and Panama. As this wave is entering the East Pacific, this will be the last time being mentioned. ...MONSOON TROUGH/ITCZ... A monsoon trough extends southwestward from near the Mauritania- Senegal border, passing south of the Cabo Verde Islands near 13N22W and Invest Area 93L mentioned in the Special Features section above to 09N36W. Numerous moderate to scattered strong convection is flaring up from 04N to 08N between the Sierra Leone- Liberia coast and 16W. Widely scattered moderate convection is seen farther west from 07N to 09N between 20W and 26W. No ITCZ is present based on the latest analysis. ...GULF OF MEXICO... A cold front curves westward from the Florida Panhandle to just north of New Orleans. Scattered showers and thunderstorms are occurring near and up to 100 nm south of the front. Otherwise, a broad surface ridge extending westward from southern Florida to near Tampico, Mexico continues to dominate the region. Fresh with locally strong westerly winds and seas of 5 to 7 ft are present across the northeastern Gulf near the cold front. Moderate to fresh southerly winds with 3 to 5 ft seas are found at the western Gulf. Gentle to moderate ESE to S winds and seas at 2 to 4 ft prevail for the rest of the Gulf. For the forecast, the surface ridge will persist through the upcoming weekend. Fresh winds will pulse north of the Yucatan peninsula each night through Sat as a diurnal trough develops and moves offshore. Elsewhere, gentle to moderate winds will prevail, locally fresh at times. Smoke from agricultural fires in Mexico will produce hazy skies over the central and western Gulf for at least the next day or two. ...CARIBBEAN SEA... Please refer to the Special Features section for information on Tropical Storm Bret, which is forecast to approach the Lesser Antilles around Thu. Convergent trade winds are triggering scattered shower and isolated thunderstorms at the Gulf of Honduras. Otherwise, the gradient between subtropical high pressure and the Colombian Low is supporting strong easterly trade winds in the south-central Caribbean with 7 to 10 ft seas. Fresh ESE winds with 6 to 8 ft seas are noted at the north-central basin. Light to gentle winds and seas of 1 to 3 ft are evident south of Cuba and near the Windward Passage. Gentle to moderate ENE to SE winds with 3 to 6 ft seas are noted for the remainder fo the basin. For the forecast, Tropical Storm Bret will begin to gradually strengthen as it moves to near 12.3N 49.2W this evening, to near 12.7N 51.9W Wed morning with maximum sustained winds 45 kt gusts 50 kt, to near 13.2N 54.5W Wed evening, to near 13.6N 57.3W early Thu with maximum sustained winds 55 kt gusts 65 kt. Bret is forecast to maintain intensity as it approaches the Lesser Antilles Thu evening and move into the eastern Caribbean Sea near 14.2N 63.6W early on Fri. Bret is forecast to begin to weaken as it nears 14.4N 70.4W early Sat with maximum sustained winds 45 kt gusts 55 kt and dissipate by early on Mon. Otherwise, the pressure gradient between the Bermuda High and the Colombian Low will support fresh to strong E trades across the central Caribbean through early Thu. Moderate to fresh E winds are expected in the Gulf of Honduras. ...ATLANTIC OCEAN... Please refer to the Special Features section for information on Tropical Storm Bret and Invest Area AL93 located in the eastern Atlantic Ocean. An outflow boundary is causing scattered showers and thunderstorms from the northeastern Florida coast to near 30N78W. Convergent southerly winds are coupling with modest divergent flow aloft to trigger scattered moderate convection at the central and southeast Bahamas to southwest of Bermuda, and north of Puerto Rico from 21N to 24N between 63W and 68W. A large dome of Mid-Atlantic High is supporting light to gentle with locally moderate winds north of 22N between 20W and the Florida-Georgia coast. To the south excluding T.S. Bret, moderate to fresh NE to E trades and seas of 5 to 7 ft exist from 08N to 22N between 30W and the Lesser Antilles. Near the Cabo Verde Islands, gentle to moderate NE trades and NW monsoonal winds are present from 12N to 22N between the Africa coast and 30W. Near the Canary Islands, light to gentle northerly winds with 1 to 3 ft seas are noted north of 22N between the northwest Africa coast and 20W. Light to gentle southerly and monsoonal winds with 4 to 6 ft seas in southerly swell prevail elsewhere in the Atlantic Basin. For the forecast W of 55W, the Mid-Atlantic High will continue to control the weather regime through Sat. Moderate to fresh S to SW winds N of 27N and W of 70W will change little through the end of the week. Otherwise, mainly gentle to moderate anticyclonic winds will prevail the next several days, locally fresh offshore northern Hispaniola and offshore northern Florida. $$ Forecaster Chan