000 AXNT20 KNHC 301017 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Sun Jul 30 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 1000 UTC. ...SPECIAL FEATURES... Central Tropical Atlantic (Invest AL96): Scattered showers and thunderstorms are noted from 18N-24N between 45W-50W associated with a tropical wave and broad area of low pressure. Seas of 8-9 ft are noted within this area of convection. Environmental conditions are forecast to be favorable for gradual development of this system during the next few days, and a tropical depression is likely to form during the early part of the week. The disturbance is expected to move northwestward at about 15 kt during the next day or so, and then turn northward over the central subtropical Atlantic by late Monday or Tuesday. Formation chance through 48 hour is medium. Please visit the latest Tropical Weather Outlook issued by the National Hurricane Center at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is analyzed in the eastern Atlantic with axis along 23W from the equator to 19N, moving westward at 10-15 kt. Scattered showers are noted along the wave axis N of 10N. A tropical wave extends its axis along 56W from 03N-19N, moving W at 10-15 kt. Scattered showers are noted along the wave axis N of 13N. A central Caribbean tropical wave extends its axis along 77W and S of 20N, moving W at 10-15 kt. Scattered moderate convection is noted along the southern portion of the wave currently moving over NW Colombia. The far northern extent of a tropical wave is over the Bay of Campeche, SE Mexico, and central America located near 94W south of 20N, moving west at 15 kt. Scattered moderate convection is in the Bay of Campeche south of 20N west of 92W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 15N17W to 13N56W. In addition to the convection in the eastern Atlantic described in the TROPICAL WAVE section above, no significant activity is noted at this time. The eastern extent of the Pacific monsoon trough is supporting scattered showers and thunderstorms in the SW Caribbean along the coast of Panama and Costa Rica. GULF OF MEXICO... A 1019 mb high pressure is centered near 28N88W. A weak surface trough currently extending across central Florida and remain the focus for scattered showers and isolated thunderstorms over the far east Gulf waters today. Light to gentle easterly winds prevail across the majority of the basin, increasing to moderate speeds in the Bay of Campeche due to the thermal trough. Seas are 1-3 ft in the northern Gulf and 2-4 ft in the SW Gulf. For the forecast, the surface ridge will remain the dominant feature across the basin through early this week. This will support gentle to moderate winds, except over the eastern Bay of Campeche, where winds will be enhanced by a thermal trough that will emerge off the Yucatan Peninsula each night. The weak surface trough across central Florida will dissipate today. High pressure will shift E into the east Gulf Tue and Wed and allow for moderate return flow to develop across the W Gulf. CARIBBEAN SEA... Please refer to the TROPICAL WAVES section above for information on the wave moving across the central Caribbean. The gradient between the expansive subtropical high and lower pressure over Colombia is supporting enhanced easterly trades winds across the basin. Trades are strong in the south-central Caribbean with 8-9 ft seas, and fresh in the remainder of the central basin with 7-8 ft seas, and moderate to fresh in the eastern and NW Caribbean with 5-7 ft seas. For the forecast, the pressure gradient between the Bermuda High and lower pressure over Colombia will continue to induce pulsing fresh to strong trades across the central Caribbean through Mon, then become confined to the south central Caribbean through the week. A strong tropical wave is expected to move across the Tropical Atlantic and reach 60W by this evening. A broad area of low pressure has developed in the vicinity of the wave and is expected to move NW into the open Atlantic through Wed. ATLANTIC OCEAN... Please refer to the sections above for information on Invest AL96 and the tropical waves moving across the basin. The weather pattern is dominated by a subtropical high pressure ridge with its axis oriented E-W along 33N. In the western Atlantic winds are moderate to fresh from the S-SE with 4-6 ft seas. Scattered moderate convection is noted N of 28N and W of 78W. In the central Atlantic, winds are gentle to moderate from the E, with seas generally 4-6 ft in the central Atlantic. In the eastern Atlantic, the gradient between the subtropical high pressure and lower pressure over Africa is supporting moderate to fresh NE winds and 6-7 ft seas. An area of Saharan Air is observed east of 40W and north of 11N. Lower visibility and hazy skies may be possible within this area. For the forecast west of 55W, high pressure centered over the central Atlantic will gradually shift eastward through Tue, and will maintain moderate to fresh trade winds primarily S of 25N through Mon. Fresh trades will pulse each late afternoon through evening N of Hispaniola and over the Windward Passage. Developing surface low pressure across the central Atlantic near 20N48W will move NW then N across the NE offshore zones Mon through Wed before exiting the region to the N. $$ ERA