000 AXNT20 KNHC 160602 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Wed Aug 16 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 0550 UTC. ...TROPICAL WAVES... The axis of a tropical wave is over west Africa near 16W from 07N to 18N, moving W at 10-15 kt. Numerous moderate with isolated strong convection is occurring from 07N to 13N between 20W and 26W and E of the wave axis inland west Africa. Scattered moderate convection is from 10N to 17N between 17W and 20W. The tropical wave is forecast to move off the west coast of Africa later this morning. Some slow development of this system is possible later this week and into the weekend while it moves generally west- northwestward or northwestward across the eastern Atlantic. Environmental conditions are expected to become more unfavorable for development by early next week. The axis of a tropical wave is in the central Atlantic near 36W, from 07N to 19N, moving W at 15 kt. Scattered moderate convection is noted from 07N to 16N between 30W and 43W. Environmental conditions appear to be conducive for some gradual development of this system during the next several days as it moves to the west- northwestward or northwestward between 10-15 mph across the tropical Atlantic through the weekend. The axis of a tropical wave is in the E Caribbean near 62W, from 10N to 18N, moving W at 15-20 kt. Scattered to isolated showers are occurring across the Windward Islands and adjacent waters. The axis of a tropical wave is moving across Central America near 85W, from the Gulf of Honduras southward into the east Pacific, moving W at 15-20 kt. Scattered showers are occurring in the Gulf of Honduras. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through coastal Dakar near 14N17W to 12N22W to 11N37W to 12N48W. See the Tropical Waves section above for a description of showers and thunderstorms. GULF OF MEXICO... A weak pressure gradient is across the basin providing light to gentle variable winds and seas of 1 to 2 ft, except in the Bay of Campeche where a surface trough is supporting moderate NE to E winds and 3 to 4 ft seas. Aside from slightly higher winds, the trough is generating scattered showers in the SW gulf. Similar convective activity is occurring across the north-central and NE coastal waters ahead of a stationary front N of the area. The tail of a surface trough that extends along most of the Florida Peninsula is supporting scattered heavy showers across the Florida Keys and the Florida Straits. Recent scatterometer data show locally fresh SE winds behind the trough in the Florida Straits. For the forecast, a trough will move off the Yucatan Peninsula each night through late week, supporting fresh winds off northwest Yucatan. Elsewhere, a ridge over the Gulf will support mostly gentle to moderate winds and slight seas across the basin through Sat. CARIBBEAN SEA... See the Tropical Waves section above for a description of showers and thunderstorms occurring across the basin. The tail of a surface trough that extends from the Florida Peninsula is generating heavy showers across the western and central Cuba offshore waters and in the Yucatan Channel. Scattered to isolated showers are occurring in the SW Caribbean associated with the E Pacific monsoon trough. Subtropical high pressure N of the area is maintaining moderate to fresh trades across the eastern, central and southwest Caribbean along with seas of 5 to 7 ft. Gentle to locally moderate winds are in the NW basin. For the forecast, ridging over the western Atlantic will support fresh to locally strong winds across mainly the south-central Caribbean into today. Moderate winds and seas will prevail elsewhere through the weekend. ATLANTIC OCEAN... A surface trough is moving westward over the eastern Straits of Florida, from 27N7.5W to 24N81W. Scattered thunderstorms are noted from 22N to 269, and west of 72W through the Straits of Florida. Scattered moderate convection is also noted offshore NE Florida, north of 28N and W of 80W. An upper-level low centered near 26N68W is only able to induce isolated showers and tstorms from 22N to 29N between 65W and 70W as a large plume of dry Saharan dust has recently caught up with the upper-low. Surface ridging dominates the remainder of the basin, anchored by a 1024 mb high pressure center near 34N41W. A surface ridge axis extends WSW from that high to the NW Bahamas. Moderate to fresh NE to E trade winds from 15N to 26N between 35W and 60W, where seas are 6 to 8 ft. Earlier ASCAT data depicted moderate to fresh ESE trades north of Hispaniola through the SE Bahamas and in the Windward Passage, where seas are likely 4 to 5 ft. Gentle to moderate wind speeds are farther north, closer to the ridge axis. Over the far NE Atlantic, from the Canary Islands to the coast of Western Sahara, fresh to strong NE winds and seas of 7 to 8 ft prevail. Of note, a dry airmass due to Saharan dust covers much of the basin from 13N to 27N, and east of 70W. For the forecast W of 55W, fresh to locally strong winds will pulse off Hispaniola this evening. Fresh E winds will form S of 25N starting Thu. A cold front will approach the NW waters then stall, but fresh SW winds can be expected Thu and Thu night in the NW waters. Gentle to moderate winds will prevail elsewhere. $$ Ramos