000 AXNT20 KNHC 301750 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Central Tropical Atlantic (Invest AL96): A broad area of low pressure is located a little less than 1000 miles east-northeast of the Leeward Islands, near 21N50W. Scattered moderate convection is from 19N to 23N between 48W and 51W. Surface winds are currently fresh to locally strong, with seas of 7-9 ft. Environmental conditions are forecast to be marginally 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 this week. The system is expected to move northwestward at about 15 mph during the next day or so, and then turn northward over the central subtropical Atlantic by late Monday or Tuesday. This system has a MEDIUM chance of developing into a tropical cyclone through 48 hrs. Please see 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 its axis along 24W from the equator to 19N, moving westward at 5-10 kt. No convection is noted at this time. A tropical wave extends its axis along 60W from 18N58W to 04N61W, moving W at 10-15 kt. This wave has been relocated based on the 1200 UTC Upper Air Soundings from Barbados and the Virgin Islands. Scattered showers are noted along the wave axis N of 13N. A central Caribbean tropical wave extends its axis along 78W S of 20N, moving W at 10-15 kt. Scattered showers are over Panama and the far SW Caribbean. The tropical wave previously over the Bay of Campeche has moved inland over Mexico. Scattered showers and tstorms are near Tampico in the lee of the wave. Subsequent information on this tropical wave can be found in the East Pacific Tropical Weather Discussion. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 18N16W to 10N40W. The eastern extent of the East Pacific monsoon trough is supporting scattered showers and thunderstorms in the SW Caribbean along the coast of Panama and Costa Rica. GULF OF MEXICO... 1020 mb high pressure is centered near 29N93W. A weak surface trough is in the E Bay of Campeche. Light to gentle easterly winds prevail across the majority of the basin, increasing to moderate speeds in the Bay of Campeche. Seas are 1-3 ft across the basin. 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. A weak surface trough currently extending across central Florida and along the SW Florida coastal waters will remain the focus for scattered showers and isolated thunderstorms over the far east Gulf waters 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/Panama is supporting enhanced easterly trades winds across the basin. Trades are fresh to strong in the central Caribbean with 7-9 ft seas, and moderate to fresh in the eastern and western Caribbean with 4-7 ft seas. At 1500 UTC, the Maersk Gerda reported an observation that indicated surface winds of 30 kt SE of Kingston, Jamaica, within showers and tstorms. For the forecast, the pressure gradient between high pressure over the central Atlantic and lower pressure over Colombia will maintain pulsing fresh to strong trades across the central Caribbean through Mon morning, then become confined to the south central Caribbean through the week. A strong tropical wave is across the Tropical Atlantic along 59W-60W. A broad area of low pressure has separated from the wave near 20.5N50W and is expected to move NW into the open Atlantic through Wed. ATLANTIC OCEAN... Please refer to the SPECIAL FEATURES and TROPICAL WAVES sections. 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. In the central Atlantic, trades are gentle to moderate with seas generally 4-6 ft. In the eastern Atlantic, NE winds are gentle to moderate with 4-6 ft seas. This morning's scatterometer data indicates NE winds are fresh to locally strong between the Canary Islands. For the forecast west of 55W, high pressure centered over the central Atlantic will gradually shift eastward through the week, and will maintain moderate to fresh trade winds S of 23N through Mon. Fresh trades will pulse each late afternoon through evening N of Hispaniola and over the Windward Passage. Surface low pressure across the central Atlantic near 20.5N50W will move NW then N across the NE offshore zones late Mon through early Wed before exiting the region to the N. A weak frontal trough will sink S into the waters offshore of NE Florida Tue night and move SE and reach from near Bermuda to the central Bahamas by Thu. $$ Mahoney