000 AXNT20 KNHC 291603 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sat Jul 29 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 1600 UTC. ...TROPICAL WAVES... A new tropical wave is being analyzed in the eastern Atlantic extending along 19W from the equator to 19N. Scattered moderate convection is observed from 07N to 10N between 15W and 31W, enhanced by the monsoon trough. A central Atlantic tropical wave extends along 20N43W to 03N49W. A 1013mb low pressure is centered along the wave near 16N44W. While this feature is only producing disorganized cloudiness and showers, environmental condtions are expected to be favorable for gradual development during the next few days, and a tropical depression is likely to form early next week. The disturbance is forecast to move west-northwestward to northwestward at about 15 kt during the next day or so, and then turn north-northwestward to northward over the central subtropical Atlantic Monday and Tuesday. This feature has a low chance of tropical cyclone development through 48 hours and a high chance over the next seven days. Meanwhile the tropical wave is moving west at about 15 kt. Similar motion is expected to continue after the distrubance separates from the wave. A Caribbean tropical wave extends along 68W from the Mona Passage to Venezula, moving west at around 15 kt. Scattered moderate convection is observed from 12N to 16N between 63W and 67W. A tropical wave over SE Mexico and central America extends along 90W south of 20N, moving west at around 15 kt. While the majority of the convection of has moved into the Pacific, showers and thunderstorms are noted in the Gulf of Honduras and Bay of Campeche. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 14N17W to 13N52W. In addition to the convection in the eastern Atlantic described in the tropical wave section, scattered moderate convection is observed from 12N to 16N between 50W and 60W. 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 few isolated showers and thunderstorms are noted in the SW Gulf. Otherwise, weak surface ridging prevails across the Gulf. Easterly winds are light to gentle acorss the majority of the basin, increasing to moderate in the Bay of Campeche. Seas are 1-3 ft in the northern Gulf and 2-4 ft in the southern Gulf. For the forecast, a weak surface ridge will remain the dominant feature across the basin through early next 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. A weak surface trough currently extending from northern Florida to offshore of Tampa Bay will drift W across the eastern Gulf today and become the focus for scattered showers and isolated thunderstorms. CARIBBEAN SEA... Please refer to the TROPICAL WAVES and MONSOON TROUGH/ITCZ section above for convection in the Caribbean Sea. The gradient between the expansive subtropical high and lower pressure over Colombia is supporting enhaced easterly trades winds across the basin. Winds are strong in the south-central Caribbean with 8-10 ft seas, fresh in the remainder of the central basin with 6-8 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 induce pulsing fresh to strong trades across the entire central Caribbean through the weekend, then become confined to the south central Caribbean through early next week. A strong tropical wave over Central America will continue to produce scattered showers and thunderstorms across the W Caribbean today. A strong tropical wave is expected to move across the Tropical Atlantic and reach 55W by late Sun. 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... The weather pattern is dominated by a subtropical high pressure ridge oreinted E-W along 32N. In the western Atlantic winds are gentle to moderate from the SE-S with 4-6 ft seas. In the central Atlantic, winds are gentle to moderate from the E with locally fresh to strong winds near the tropical wave distrubance. Seas are generally 4-6 ft in the central Atlantic, reaching up to 9 ft near the disturbance. In the eastern Atlantic, the gradient between the subtropical high pressure and lower pressure over Africa is supporting moderate to fresh NE winds and 5-8 ft seas. An area of Saharan Air is observed east of 40W and north of 12N. 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 the weekend, and will maintain moderate to locally fresh trade winds S of 23N. 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 today will move NW then N across the eastern offshore zones Sun through Wed. $$ Flynn