000 AXNT20 KNHC 200606 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 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 0000 UTC surface analysis and satellite imagery through 0350 UTC. ...SPECIAL FEATURES... Tropical Storm Bret: As of 03 UTC, Tropical Storm Bret is centered near 11.4N 43.5W, or about 1050 nm E of the southern Windward Islands, moving W at 16 kt. The estimated minimum central pressure is 1008 mb. Maximum sustained winds are 35 kt with gusts to 45 kt. Seas 12 ft or greater extend up to 60 nm in the N semicircle. As Bret interacts with subtropical high pressure to the north, strong winds and rough seas in excess of 8 ft reach as far north as 18N. Satellite imagery continues to become better defined. A central dense overcast is developing near the center of Bret, with outer rain bands extending up to 180 nm. On the forecast track, Bret is forecast to initially strengthen before moving across the Lesser Antilles near hurricane intensity on Thursday and Friday bringing a risk of flooding from heavy rainfall, hurricane-force winds, and dangerous storm surge and waves. 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 wed-site 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 extends along 30W from 03N to 15N, moving W at around 15 kt. A 1012 mb low pressure is analyzed along the wave axis near 08N30W. Winds are currently strong north of the low-pressure center, generating 6-9 ft seas. Scattered moderate with isolated strong convection is observed from 07N to 11N between 29W and 36W. Environmental conditions appear favorable for further development, and a tropical depression could form in the next couple days while the system moves westward at 10-15 kt across the eastern and central tropical Atlantic. The current tropical weather outlook assigns a medium (60%) probability of formation through the next 48 hours, and a high (70%) probability over the next seven days. Please refer to the latest Tropical Weather Outlook at www.hurricanes.gov, for more details. ...TROPICAL WAVES... A central Atlantic tropical wave extends along 53W from 01N to 15N, moving west at 10-15 kt. The northern portion of the wave is approaching NDBC buoy 41040, which is currently reporting 15 kt ENE winds and 6 ft seas. Associated convection remains isolated and weak. A central Caribbean Sea tropical wave extends along 75W from 03N to 14N, moving west at around 10 kt. The northern portion of the wave is approaching NDBC buoy 42058, which is reporting 20 kt ENE winds and 8 ft seas. No significant convection is occurring near this wave. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 16N16W to Invest Area 93L near 08N30W to 10N36W. No ITCZ is currently present. All significant convection is described in the Special Features section. GULF OF MEXICO... The subtropical Atlantic ridge extends across Florida into the Gulf waters. Scattered showers and thunderstorms are noted in the north-central and NE Gulf, particularly within 180 nm of the coast. The pressure gradient between the ridge and lower pressure over Mexico and the southern US is supporting moderate to fresh S-SW winds in the western and northern Gulf, where seas are 4-6 ft. A surface trough across the Yucatan Peninsula is supporting moderate to fresh NE-E winds in the south-central Gulf. Elsewhere, winds are gentle to moderate and seas are in the 2-4 ft range. Smoke due to agriculture fires over Mexico may be reducing visibilities along the coast of Mexico and the western Bay of Campeche where the latest SAB analysis indicates a medium concentration. For the forecast, high pressure extending from the Straits of Florida to the upper Texas coast will generally persist through the week and into the upcoming weekend. Fresh winds will pulse north of the Yucatan peninsula each night through the forecast period 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 late this week. The gradient between subtropical high pressure and lower pressure over the SW Caribbean is supporting strong easterly trade winds in the central Caribbean, where seas are in the 6-9 ft range. Fresh SE winds are noted in the Gulf of Honduras. Gentle winds are noted in the lee of Cuba and Windward Passage, where seas are 1-3 ft. Winds are moderate elsewhere, with 4-6 ft seas. For the forecast, Tropical Storm Bret near 11.4N 43.5W 1008 mb at 11 PM EDT moving W at 16 kt. Maximum sustained winds 35 kt gusts 45 kt. Bret will move to 11.8N 45.8W Tue morning, 12.3N 48.7W Tue evening, 12.8N 51.4W Wed morning, strengthen to a hurricane near 13.3N 53.9W Wed evening, 13.8N 56.7W Thu morning, and weaken to a tropical storm near 14.3N 59.4W Thu evening. Bret will change little in intensity as it moves to 15.0N 64.5W late Fri. 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. A surface trough extends across the western Atlantic from 31N74W to 26N80W. Numerous moderate with isolated strong convection is observed from 24N to 31N west of 78W, with widely isolated thunderstorms throughout the remainder of the western subtropical Atlantic. A 1027 mb high pressure centered near 31N47W is the dominate feature across the basin. North of 20N, anticyclonic winds are gentle to moderate with 3-6 ft seas. South of 20N and outside of the immediate impacts from Tropical Storm Bret, fresh NE-E winds and 5-7 ft seas are observed. For the forecast W of 55W, Bermuda high pressure extends a ridge SW through the central Bahamas to the SE Gulf of Mexico, and will continue to dominate through mid-week. A weak cold front off the SE US coast will linger and gradually dissipate through the early part of the week with locally fresh winds E of it tonight. Mainly gentle to moderate anticyclonic winds will prevail the next several days, locally fresh offshore N Hispaniola and offshore N Florida. $$ Flynn