861 AXNT20 KNHC 221757 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Thu Jun 22 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 1730 UTC. ...SPECIAL FEATURES... Tropical Storm Bret is centered near 13.4N 58.9W at 22/1800 UTC or 40 nm ENE of Barbados moving W at 9 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Recent satellite imagery indicate that westerly wind shear has increased over Bret and most of the deep convection is located over the eastern quadrant. Seas near the center are around 23 ft and expected to gradually subside over the next few days. Little change in strength is forecast today while Bret approaches the Lesser Antilles. Gradual weakening is anticipated over the next couple of days, and the system is likely to dissipate over the central Caribbean Sea by Saturday night or early Sunday. The center of Bret is expected to move across the Lesser Antilles this evening and tonight, and then move westward across the eastern and central Caribbean Sea Friday and Saturday. 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 Four is centered near 11.3N 42.9W at 22/1500 UTC or 795 nm E of the Lesser Antilles moving W at 10 kt. Estimated minimum central pressure is 1007 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Easterly shear is maintaining scattered moderate to isolated strong convection within 240 nm west of the exposed low level center. Combined seas are estimated to be around 10 ft. Seas are forecast to build to near 11 ft by tonight. Some strengthening is forecast during the few days, and the depression is expected to become a tropical storm soon. A weakening trend is forecast to commence over the weekend. The depression is expected to remain well east of the northern Leeward Islands through early next week. 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... An eastern Atlantic tropical wave axis was along 22W, south of 14N, moving westward at 5-10 kt. Isolated moderate convection is noted south of 10N and between 20W and 25W. A Caribbean Sea tropical wave has been relocated along 77W based on RAOBs from Santo Domingo, Dominican Republic, and Kingston Jamaica, and wave diagnostics data. The wave axis is south of 19N, moving westward at 10-15 kt. No deep convection is associated with this feature. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Guinea near 10N14W to 09N32W. Scattered moderate convection is observed south of 10N and east of 20W. Similar convection is noted south of 08N and between 25W and 35W. ...GULF OF MEXICO... A weak stationary frontal boundary along the northern Gulf coast and divergence aloft result in scattered moderate to isolated strong convection north of 27N and east of 93W. Elsewhere, weak high pressure prevails. Gentle to moderate southerly winds are prevalent across the basin. However, stronger winds are likely in association with the strong convection previously mentioned. Seas of 3-5 ft are found over most of the Gulf except 1-3 ft in the southeast waters. For the forecast, the aforementioned high pressure extends from southwest Florida to the upper Texas coast will move little through early next week. Fresh winds will pulse north of the Yucatan peninsula each night through Fri night as a trough develops each evening and moves offshore. A nearly stationary front along the northeast Gulf coast will continue to bring scattered thunderstorms to those waters through Fri. Smoke from agricultural fires in Mexico will continue to result in haze over sections of the far western Gulf through at least the next couple of days. ...CARIBBEAN SEA... Please read the SPECIAL FEATURES section for details on Tropical Storm Bret approaching the Lesser Antilles. Scattered moderate to isolated strong convection is seen in the western Caribbean Sea, south of 20N, in association to upper level divergence and abundant tropical moisture. Similar convection is also occurring off the northern Panamanian coast, mainly within 90 nm. In the remainder of the Caribbean, a drier environment is suppressing the development of showers and thunderstorms. Fresh to strong easterly trade winds are evident across the basin, especially south of 19N. This is confirmed by a recent scatterometer satellite pass and surface observations. Seas of 6-9 ft are present in the area described. Elsewhere, moderate or weaker winds and slight to moderate seas prevail. For the forecast, Tropical Storm Bret near 13.8N 57.7W 999 mb at 11 AM EDT moving W at 12 kt. Maximum sustained winds 60 kt gusts 75 kt. Bret will maintain intensity as it moves to near 14.0N 60.0W this evening, then begin to weaken as it moves to near 14.3N 63.2W Fri morning, to near 14.5N 66.7W Fri evening with maximum sustained winds 50 kt gusts 60 kt, to near 14.6N 70.3W Sat morning, to near 14.5N 74.0W Sat evening with maximum sustained winds 40 kt gusts 50 kt and dissipate Sun morning. The remnant trough will continue westward to the western Caribbean into early next week accompanied by fresh east to southeast winds. Farther east, Tropical Depression Four near 11.3N 42.9W 1007 mb at 11 AM EDT moving WNW at 13 kt. Maximum sustained winds 30 kt gusts 40 kt. Tropical Depression Four will strengthen to a tropical storm near 11.8N 44.7W this evening with maximum sustained winds 35 kt gusts 45 kt, move to near 12.8N 47.2W Fri morning and continue to strengthen as it moves to near 14.0N 49.6W Fri evening with maximum sustained winds 45 kt gusts 55 kt, then to near 15.5N 52.2W Sat morning with maximum sustained winds 50 kt gusts 60 kt, reach to near 17.1N 54.8W Sat evening, and begin to weaken as it reaches near 18.6N 57.4W Sun morning. Tropical Storm Four will continue to weaken as it tracks well east of the northern Leeward Islands through early next week. ...ATLANTIC OCEAN... Please read the SPECIAL FEATURES section for details on Tropical Storm Bret and Tropical Depression Four. Divergence aloft on the southeast side of an upper trough over the eastern Gulf is supporting scattered showers and thunderstorms, mainly west of 70W. In the rest of the SW Atlantic, weak high pressure suppresses the formation of deep convection. Moderate easterly trades are found south of 24N with seas 4-6 ft. Similar southerly winds are present in the offshore waters of northeast Florida. Seas in this area are 3-5 ft. Elsewhere, west of 55W, light winds and slight seas are prevalent. In the central and eastern tropical Atlantic, a broad subtropical ridge maintains fairly tranquil weather conditions despite a weak cold front entering the region along 30N50W. Fresh northerly winds and 4-6 ft seas are occurring south of 24N and east of 25W. In the remainder of the basin outside of the influence of the tropical cyclones mentioned, moderate or weaker winds and moderate seas prevail. For the forecast for waters west of 55W, Tropical Depression Four near 11.3N 42.9W 1007 mb at 11 AM EDT moving WNW at 13 kt. Maximum sustained winds 30 kt gusts 40 kt. Tropical Depression Four will strengthen to a tropical storm near 11.8N 44.7W this evening with maximum sustained winds 35 kt gusts 45 kt, move to near 12.8N 47.2W Fri morning and continue to strengthen as it moves to near 14.0N 49.6W Fri evening with maximum sustained winds 45 kt gusts 55 kt, and move to near 15.5N 52.2W Sat morning with maximum sustained winds 50 kt gusts 60 kt. Tropical Storm Four is forecast to move to the west-northwest through Sat night and well east of the northern Leeward Islands through early next week as it weakens to a minimal tropical storm. Otherwise, high pressure extending from the north-central Atlantic to the central Bahamas will lift northward through early Sun ahead of tropical cyclone Four. $$ KRV/SDR