000 AXNT20 KNHC 211004 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Wed Jun 21 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 0600 UTC surface analysis and satellite imagery through 0945 UTC. ...SPECIAL FEATURES... Tropical Storm Bret: Tropical Storm Bret is centered near 12.8N 51.4W at 21/0900 UTC or 560 nm E of the Windward Islands moving W at 14 kt. Estimated minimum central pressure is 1001 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Seas 12 ft or greater are observed within 90 NM NE quadrant...45 NM SE quadrant...30 NM SW quadrant...and 60 NM NW quadrant with seas to 16 ft. Scattered to numerous moderate convection is noted from 10N-16N between 48W-53W. Bret is expected to continue moving west for the next several days. On the forecast track, the center of Bret is expected to move across portions of the Lesser Antilles Thursday afternoon and Thursday night, and then move across the eastern Caribbean Sea on Friday. Through Saturday, storm total rainfall amounts of 3 to 6 inches with maximum amounts of 10 inches are possible across portions of the Lesser Antilles from Guadeloupe south to Grenada, including Barbados. The heavy rainfall could lead to flash flooding, especially across areas of higher terrain. Isolated urban flooding is also possible. Please read the latest HIGH SEAS FORECAST issued by National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, 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. Invest Area (AL93): A tropical wave extends along 36W from 03N to 15N, moving west at about 10-15 kt. A 1011 mb low is analyzed along the wave near 10N37W. Scattered showers and thunderstorms are noted from 05N-13N between 35W-42W. Strong winds are noted in the northern semicircle of the low, where seas are in the 6-8 ft range. Environmental conditions appear conducive for further development of this system, and a tropical depression will likely form during the next couple of days while the system moves westward across the central tropical Atlantic. The latest Tropical Weather Outlook assigns a high (70%) chance of tropical cyclone formation in the next 48 hours, and a high (80%) chance over the next seven days. Refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave extends along 61W from 06N to 18N, moving west at around 10-15 kt. Scattered showers are observed from 11N to 17N between 60W and 63W. A tropical wave extends along 82W from 04N to 15N, moving west at around 10 kt. The convection related to this wave remains across the southern portion of the wave over the EPAC waters. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 14N17W, through Invest Area AL93 to 10N43W. No ITCZ is currently present in the Atlantic. A large cluster of numerous moderate with scattered strong convection is observed along the W coast of Africa from 03N to 12N and E of 22W. This activity may be signaling the next tropical wave will soon emerge off the coast of Africa. ...GULF OF MEXICO... A stationary front extends across the southern U.S. Gulf Coast to northern Florida. Scattered showers and thunderstorms are observed north of 26N between 83W and 94W. Elsewhere, a high- pressure ridge continues to dominate the basin. Anticyclonic winds are mostly gentle to moderate outside of thunderstorms. Another exception is near the Yucatan Peninsula, where a surface trough is supporting fresh to strong winds. Seas are generally 3-5 ft across the basin, with buoys reporting up to 7 ft within thunderstorms in the NE Gulf. 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 sections above for information on Tropical Storm Bret and the tropical waves moving across the basin. The gradient between subtropical high pressure and lower pressure over northern Colombia is supporting fresh to strong trade winds in the central Caribbean, where seas are in the 7-9 ft range. Strong winds are also noted in the Gulf of Honduras. Winds are gentle to moderate elsewhere, with 3-6 ft seas. For the forecast, Tropical Storm Bret will move to 13.1N 53.3W this afternoon, 13.5N 55.7W Thu morning, 13.8N 58.5W Thu afternoon, 14.2N 61.8W Fri morning, 14.5N 65.3W Fri afternoon, and 14.8N 69.0W Sat morning. Bret will weaken to a tropical depression over 15.0N 76.0W by early Sun. An area of low pres currently several hundred nautical miles SW of the Cabo Verde Islands is forecast to move westward at 10-15 kt across the eastern and central tropical Atlantic through the week, possibly reaching and moving through the tropical N Atlantic waters this weekend with a high potential for tropical cyclone formation. Otherwise, the pres 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 to SE winds are expected in the Gulf of Honduras through late Wed night, then increase to fresh to strong through Thu, to near gale Thu night and diminish back to fresh to strong Fri. ...ATLANTIC OCEAN... Please refer to the Special Features section for information on Tropical Storm Bret and Invest Area AL93. Scattered showers and thunderstorms are observed in the far western subtropical Atlantic near Florida and the Bahamas. SW winds are moderate to fresh in this area. Otherwise a 1023 mb high pressure centered near 29N43W dominates the weather pattern. Winds are gentle to moderate N of 25N and moderate to fresh south of 25N. Seas are 3-6 ft outside of impacts from Tropical Storm Bret. For the forecast W of 55W, broad high pressure ridging extending southwest across the area will continue to control the weather regime throughout during the rest of the forecast period. Moderate to fresh south to southwest 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 N Hispaniola and offshore N Florida. AL93 is forecast to move westward at 10-15 kt across the eastern and central tropical Atlantic through the week, possibly reaching the tropical N Atlantic waters this weekend with a high potential for tropical cyclone formation. $$ ERA