000 AXNT20 KNHC 131752 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sun Aug 13 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 1700 UTC. ...TROPICAL WAVES... An eastern Atlantic tropical wave is near 33W from 15N southward, and moving west at 15 to 20 kt. Scattered moderate convection is noted from 07N to 09N between 27W and 34W. An eastern Caribbean tropical wave is near 62W from near the northern Leeward Islands southward into northeastern Venezuela. It is moving west around 20 kt. Scattered showers and isolated thunderstorms are occurring from the southern Windward Islands northwestward to just south of Puerto Rico. A western Caribbean tropical wave is near 86W from the Yucatan Channel southward across Honduras and Nicaragua into the East Pacific. It is moving west around 10 kt. Scattered showers and isolated thunderstorms are seen at the Yucatan Channel and near the east coast of the Yucatan Peninsula. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic along the Senegal coast near Dakar, then extends southwestward across 10N30W to 07N46W. Outside the influence of the aforementioned tropical wave, scattered moderate convection is noted near and south of the trough from 07N to 15N between the Senegal-Guinea coast and 27W. An ITCZ continues northwestward from 07N46W to 09N56W. Scattered showers are noted near and up to 100 nm south of the ITCZ. The eastern end of the East Pacific monsoon trough is triggering scattered showers and isolated thunderstorms in the Caribbean waters adjacent to Costa Rica and western Panama. ...GULF OF MEXICO... A surface trough stretching southward from northern Florida to near the Florida Keys is generating scattered showers and thunderstorms near southwestern Florida, including the Florida Keys and Florida Straits. Modest convergent surface winds are coupling with moderate easterly wind shear aloft to spark isolated thunderstorms at the north-central Gulf and western Bay of Campeche. A 1018 mb high at the northeastern Gulf and its related surface ridge continue to dominate much of the region. Light to gentle winds and seas of 1 to 2 ft exist at the northeastern and east-central Gulf. Gentle to moderate ESE to S winds with 2 to 5 ft seas prevail for the rest of the Gulf, including the Bay of Campeche. For the forecast, a trough will move off the Yucatan Peninsula each night supporting fresh winds off northwest Yucatan. Elsewhere, a ridge over the northern Gulf will support mostly gentle to moderate winds and slight seas across the basin through Thu. ...CARIBBEAN SEA... A robust upper-level low at the central Caribbean near 16N75W is causing widely scattered showers and isolated thunderstorms from 13N northward to near Jamaica and Hispaniola. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections above for additional weather in the Caribbean Basin. An easterly trade-wind pattern persists across the basin. Fresh to strong ENE winds and seas of 6 to 9 ft are present at the central basin. Gentle to moderate E winds and 3 to 5 ft seas are found near the Cayman Islands and west of Jamaica. Light to gentle monsoonal winds and seas at 3 to 5 ft in easterly swell exist near Costa Rica and Panama. Moderate to fresh ENE to ESE winds and seas at 4 to 6 ft prevail elsewhere in the basin, including the Gulf of Honduras and Windward Passage. For the forecast, ridging over the western Atlantic will support fresh to locally strong winds across mainly the south-central Caribbean through mid week, and over the Gulf of Honduras tonight. Moderate winds and seas will persist elsewhere. ...ATLANTIC OCEAN... A low to mid-level trough extends southward from off the Carolinas coast to southeastern Florida. Together with convergent southerly winds near the subtropical Atlantic Ridge, widely scattered moderate convection is evident north of 26N between 70W and the Georgia-Florida coast. Farther east, a surface trough curves southwestward from 31N57W to east of the southeast Bahamas at 21N69W. Scattered moderate convection is flaring up from 22N to 26N between 66W and 72W. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections at the beginning for additional convection in the Atlantic Basin. The subtropical Atlantic Ridge is supplying gentle to moderate E to SE to S winds and seas at 3 to 6 ft north of 20N between 60W and the Georgia-Florida coast. Farther east north of 20N between 28W and 60W, moderate to fresh NE to E trades and 6 to 9 ft seas dominate. Near the Canary Islands, moderate to fresh with locally strong NNE trades and seas of 6 to 10 ft are found north of 25N between the Africa coast and 28W. To the south, light to gentle monsoonal winds and 4 to 6 ft seas in moderate southerly swell are present from 11N to 25N between the central Africa coast and 30W, including the Cabo Verde Islands. To the west, gentle to moderate with locally fresh NE to E trades and seas of 5 to 8 ft exist from 10N to 20N between 30W and the Lesser Antilles. Gentle to moderate southerly winds with 5 to 8 ft seas in moderate to large southerly swell prevail for the remainder of the Atlantic Basin. For the forecast W of 55W, the subtropical Atlantic Ridge will lift northward ahead of a surface trough moving westward toward the Bahamas through the early part of the week. Expect moderate to fresh easterly winds south of 24N following the trough through Tue. Fresh to strong winds will pulse off Hispaniola during the late afternoons and early evenings through Tue. $$ Forecaster Chan