000 AXNT20 KNHC 231021 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 621 AM EDT Tue Jun 23 2020 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 1020 UTC. ...SPECIAL FEATURES... Subtropical Depression Four is centered near 39.3N 63.4W at 23/0900 UTC or 320 nm S of Halifax Nova Scotia moving NE at 11 kt. Estimated minimum central pressure is 1008 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Scattered moderate isolated strong convection is within 150 nm southeast semicircle of the center. 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... The axis of a tropical wave is near 40W south of 18N, moving W at 20 to 25 kt. Scattered moderate convection is seen from 06N-11N within 180 nm of the wave axis. The axis of a tropical wave is near 77W south of 17N, moving W at 25 to 30 kt. A stable air mass associated with a dense plume of Saharan dust is limiting significant convection with this wave. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from 16N16.5W to 10N26W. The ITCZ continues from 10N26W to 08N36W. It then resumes from 07N42W to 04N51W. Scattered moderate convection is noted within 210 nm N and within 60 nm S of the ITCZ between 44W-51W. GULF OF MEXICO... An upper-level low over the northwest Gulf of Mexico near 28N94W is enhancing upper-level diffluence over the north-central Gulf in a moist environment. Scattered moderate isolated strong convection is seen north 26N between 85W-92W. Scattered moderate convection is elsewhere W of 90W. High pressure of 1019 mb is centered near 26N83W. Moderate to fresh winds prevail over the western Gulf. Gentle to moderate winds prevail over the SE Gulf, and light to gentle winds prevail in the vicinity of the high pressure center. Surface ridging will prevail over the Gulf waters through the forecast period. Moderate to fresh southerly winds are forecast over the western Gulf through Thu night due to the pressure gradient between the ridge and lower pressure over Mexico. CARIBBEAN SEA... GOES-16 satellite imagery shows dense Saharan dust covers most of the Caribbean. This dry, stable air mass is inhibiting convection across the region. The exception is the far SW Caribbean, where the east Pacific monsoon trough is enhancing scattered moderate to strong convection south of 10N and west of 80W, including over portions of Panama. At the surface, the pressure gradient between high pressure north of the area and climatological low pressure over Colombia is producing fresh to strong trades across central Caribbean, reaching near gale force near the coast of Colombia. Fresh to strong winds prevail over the Gulf of Honduras, and moderate winds are noted over the remainder of the NW Caribbean. Fresh winds prevail over the eastern Caribbean. Fresh to strong trades will prevail across the central Caribbean through the week. Winds will pulse to near gale force off the coast of Colombia each night through Sat night with seas building to 12 ft and higher during the strongest winds. Fresh to strong winds are expected in the Gulf of Honduras through Sat night. ATLANTIC OCEAN... See section above for information on Subtropical Depression Four. A broad surface ridge covers the western Atlantic, with light to gentle wind speeds north of 22N west of 60W. Scattered moderate isolated strong convection is offshore northern Florida from 26N- 32N between 79W-81W. Farther east, a surface trough extends from 32N50W to 26N52W to 22N57W. Isolated showers are near the trough axis. Another surface trough extends from 30N40W to 23N40W. Isolated showers are near the trough axis. In the tropics, fresh trades prevail S of 20N. High pressure extends from the central Atlantic to Florida and will prevail across the offshore waters through Saturday. Fresh to occasionally strong easterly winds will pulse across the waters north of Hispaniola each night through Sat night. $$ AL/Hagen