061 AXNT20 KNHC 310550 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sun Jul 31 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 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... Central Tropical Atlantic (Invest AL96): Shower and thunderstorm activity continues in association with an area of low pressure located about 750 miles east-northeast of the northern Leeward Islands. Thus, a gale warning is in effect for the waters near 22N51.5W. Environmental conditions are forecast to be marginally favorable for development over the next few days, and a tropical depression is likely to form during the next day or so. The system is expected to move northwestward at about 10 to 15 kt today, and then turn northward over the central subtropical Atlantic by late tonight or Tuesday. There is a high chance of tropical cyclone development of this system through the next 48 hours. Additional information on this system, including gale warnings, can be found in High Seas Forecasts issued by the National Weather Service. 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 near 28W from 04N to 20N, moving westward at around 10 kt. Scattered moderate convection is seen behind the wave from 08N to 13N E of 27W. A tropical wave is located near 62W, crossing the Lesser Antilles and moving W at around 10 kt into the Caribbean Sea. Scattered moderate convection is noted in the vicinity of the Leeward Islands in association with this wave. A western Atlantic tropical wave is located near 81W, S of western Cuba, moving W at around 15 kt. No significant convection is seen with this wave. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 19N16W to 08N41W. Convection along the trough is primarily associated with the eastern Atlantic tropical wave, described in the section above. GULF OF MEXICO... Scattered showers and thunderstorms over New Orleans/Alabama have triggered the formation of an outflow boundary over the north-central Gulf as this activity drifts mainly southward. A thermal trough has developed over the Yucatan Peninsula and moderate convection is seen in the Bay of Campeche. Elsewhere, a 1017 mb high pressure is centered just offshore the NE Gulf Coast and is dominating the sensible weather. Outside of convection, winds are mainly gentle with seas of 1 to 3 ft, except in the Bay of Campeche, where moderate winds with seas 2 to 4 ft are seen. For the forecast, a surface ridge will remain the dominant feature across the basin through early this week, currently anchored by a 1017 mb high centered near 29N93W. 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. High pressure will shift SE into the east Gulf Tue and Wed and allow for moderate return flow to develop across the W Gulf Wed through Fri. CARIBBEAN SEA... Please refer to the TROPICAL WAVES section above for information on the waves moving across the 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 to 9 ft seas, and mainly moderate winds in the eastern and western Caribbean with 4 to 7 ft seas. For the forecast, the aforementioned 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 Thu. A 1011 mb low pressure near 22N51.5W is expected to move NW into the open Atlantic through Wed. As this occurs, Atlantic ridging N of the area will be disrupted. ATLANTIC OCEAN... Please refer to the SPECIAL FEATURES section for details on low pressure well NE of the Leeward Islands that has a potential of tropical development. Please refer to the TROPICAL WAVES and MONSOON TROUGH/ITCZ sections for other areas of convection in the tropical Atlantic. In addition, an area of moderate convection is seen moving off the coast to Florida and Georgia N of 28N and W of 78W in association to a surface trough. The weather pattern is dominated by a subtropical high pressure ridge with its axis oriented E-W along 34N. In the western Atlantic, outside of convection, winds are moderate to locally fresh from the S-SE with 4 to 6 ft seas. In the central Atlantic, aside from where AL96 is impacting waters, trades are mainly moderate with seas generally 4 to 6 ft. In the eastern Atlantic, NE winds are moderate with 4 to 6 ft seas. The exception is fresh to locally strong winds in the vicinity of the Canary Islands. For the forecast west of 55W, the aforementioned high pressure centered over the central Atlantic will gradually shift E-NE through the week. Moderate to fresh trade winds will continue S of 23N through early Tue before diminishing. Fresh trades will pulse Mon and Tue afternoon through evening N of Hispaniola and over the Windward Passage. A gale force 1011 mb low pressure across the central Atlantic near 22N51.5W will move NW then N and brush the NE offshore zones early Tue through early Wed, likely as a tropical cyclone, before exiting the region to the N, which will act to disrupt the Atlantic ridge. 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. $$ KRV