000 AXNT20 KNHC 211023 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sun Jul 21 2024 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 1100 UTC. ...TROPICAL WAVES... An eastern Atlantic tropical wave is near 32W/33W from 20N southward, moving westward at around 10 kt. Scattered showers are noted where the wave axis meets the monsoon trough. A central Caribbean tropical wave is near 78W/79W and extends from eastern Cuba and western Jamaica southward into eastern Panama. It is moving westward at 10 kt. Scattered to numerous showers and thunderstorms are occurring over parts of Jamaica, eastern Cuba and the Cayman Islands. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through near the Mauritania/ Senegal border, then extends southwestward to 12N30W to 09N50W. The ITCZ continues westward from 09N50W to 09N60W. Scattered moderate convection is noted from 08N to 10N between 30W and 40W. ...GULF OF MEXICO... The Atlantic ridge extends westward across Florida into the Gulf of Mexico. This system is supporting gentle to moderate easterly winds S of 24N, including the Straits of Florida, with seas of 2 to 4 ft, occasionally 5 to 6 ft in the Straits of Florida. Elsewhere, light to gentle winds and seas of 1 to 3 ft prevail. Scattered to numerous shower, with embedded thunderstorms, are noted over the western Bay of Campeche, including the Veracruz area. Similar convective activity is affecting the Yucatan Channel. For the forecast, a ridge will remain in place across the Gulf waters over the next several days. It will support gentle to moderate E to SE winds and slight seas. Pulsing moderate to fresh winds are expected near and to the NW of the Yucatan Peninsula during the evening and night hours due to local effects. Scattered to numerous showers and thunderstorms are expected over the Straits of Florida and the SE Gulf tonight and Mon as the northern portion of a tropical wave moves across the area. ...CARIBBEAN SEA... The Atlantic high pressure is building over the eastern Caribbean in the wake of a tropical wave currently located along 78W/79W. As a result, the most recent scatterometer data provide observations of fresh to strong winds over the central Caribbean, including the Gulf of Venezuela where winds are 25 to 30 kt. Moderate to fresh winds are seen over the eastern Caribbean, and in the Gulf of Honduras while gentle to moderate winds prevail elsewhere, except in the SW portion of the basin, particularly S of 12N where light to gentle winds are noted. Combined seas are 6 to 9 ft in the central Caribbean, and 3 to 5 ft elsewhere, with the exception of 2 to 4 ft in the SW Caribbean S of 11N. For the forecast, the aforementioned tropical wave will move through the western Caribbean tonight and Mon. High pressure from the central Atlantic will build in its wake, with increasing fresh to strong winds and building seas, possibly peaking to 11 or 12 ft over the south-central Caribbean early on Mon. The trade winds and associated seas will diminish slightly on Tue, then increase across the eastern and central Caribbean for the remainder of the forecast period. ...ATLANTIC OCEAN... An upper-level trough extends southwestward from a low located SW of Bermuda near 30N66W to another upper-level low spinning over the central Bahamas and central Cuba. The latter low combined with the northern portion of a tropical wave is enhancing scattered to numerous showers and thunderstorms over parts of the Bahamas and eastern Cuba. At the surface, the pattern is dominated by the Bermuda-Azores high, with a 1026 mb center situated E of Bermuda near 32N59W. The gradient between the high pressure and the tropical wave is supporting an area of fresh to strong SE winds between the central Bahamas and eastern Cuba, mainly S of 23N between 74W and 77W based on recent scatterometer data. Elsewhere, moderate to locally fresh trades are noted N of 10N to about 24N. Gentle to moderate anticyclonic flow dominates the remainder of the Atlantic forecast waters with the exception of fresh to strong northerly winds between the Canary Islands and off NW Africa. Seas are generally 4 to 7 ft, except 7 to 9 ft downstream of the Canary Islands based on altimeter data. For the forecast west of 55W, the Bermuda-Azores high will continue to dominate the Atlantic forecast waters over the next several days. The related pressure gradient will support moderate to fresh easterly winds south of 25N, with winds pulsing to strong during the late afternoons and evenings off the northern coast of Hispaniola through at least mid-week. The northern portion of a tropical wave combined with an upper-level low spinning over the central Bahamas and central Cuba is producing scattered to numerous showers and thunderstorms over parts of the Bahamas, eastern Cuba, and Jamaica. This convective activity will continue to shift westward across the Bahamas, Cuba, and regional waters today, reaching the Straits of Florida tonight. Some of the thunderstorms may produce strong gusty winds and rough seas. $$ GR