842 AXNT20 KNHC 192225 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sat Jul 20 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 1800 UTC surface analysis and satellite imagery through 2200 UTC. ...TROPICAL WAVES... An eastern Atlantic tropical wave is along 27W, south of 18N, moving westward at 10-15 kt. A few showers are seen near the trough axis. An eastern Caribbean tropical wave is along 67W/68W, south of 22N, moving westward at 20-25 kt. Scattered showers and thunderstorms extend from the Leeward Islands through Hispaniola, and the adjacent northeast Caribbean. These storms may produce heavy downpours, lightning and gusty winds. A western Caribbean tropical wave is along 90W, south of 20N, moving westward at 20 kt. An upper low northwest of the tropical wave is supporting scattered moderate to isolated strong convection across southern Mexico and Guatemala. Gusty winds are possible near the stronger storms. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Mauritania near 19N16W and continues to 10N35W and to 08N50W. The ITCZ extends from 08N50W to 08N60W. A large area of Saharan dust extends across the Atlantic, and is suppressing any significant convection at this time. ...GULF OF MEXICO... A few showers and thunderstorms are active from the south-central Gulf through the northeast Gulf, around the periphery of an upper trough which is centered on an upper cyclonic circulation to the northwest of Merida, Mexico. At the surface, the Atlantic ridge extends westward into the central Gulf, supporting light to gentle breezes and slight seas across the basin. For the forecast, the Atlantic high pressure will extend westward across central Florida and to the central Gulf through Sun, then slowly lift northward to near 30N Mon through midweek. It will support gentle to locally moderate 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. ...CARIBBEAN SEA... A tropical waves is moving westward across the Caribbean Sea. Please, see the Tropical Waves section above for more details. Moderate trade winds and 5 to 7 ft seas are noted ahead of the tropical wave across the central and southwest Caribbean. Gentle to moderate SE winds and 3 to 5 ft seas are evident east of the tropical wave over the eastern Caribbean. An earlier scatterometer satellite pass indicated fresh to strong E winds off Belize earlierthis morning, following the tropical wave now over southern Mexico and Guatemala. These winds have likely diminished, and gentle to moderate E winds persist over the northwest Caribbean, supporting 3 to 5 ft seas. For the forecast, the pressure gradient between the Atlantic high pressure and the Colombian low is supporting fresh to locally strong trade winds over the central Caribbean, with mainly moderate seas. Winds and seas will diminish slightly through early Sat as a tropical wave moves through the basin. The trade winds and associated seas will increase again Sat through Mon, diminishing some Tue and increasing again Tue night in the wake of an easterly surge. ...ATLANTIC OCEAN... A few showers and thunderstorms are active north of Puerto Rico and the Virgin Islands, as far north as 22N, on the northern end of a tropical wave moving into the central Caribbean. A few showers and thunderstorms are also active over the northern Bahamas. 1029 mb high pressure is centered near 34N55W. This pattern is supporting an area of moderate to fresh winds and 6 to 8 ft seas near the northern end of the tropical wave, and just to the east of Leeward Islands. The pattern is supporting gentle to moderate winds and 4 to 6 ft seas elsewhere west of 35W. The subtropical ridge is broken up by a trough along 35N from 25N to 30W. 1022 mb high pressure is farther east of this feature, near 30N26W. This pattern is supporting mostly moderate winds and 3 to 5 ft seas east of 35W, except for fresh to strong NE winds funneling off the northwest coast of Africa and the Canary Islands. For the forecast west of 55W, a ridge will extend west- southwestward from the north-central Atlantic to across central Florida. The ridge will slowly lift north to near 30N Mon through midweek. The related gradient will support moderate to fresh easterly winds south of 26N, with winds pulsing to strong during the late afternoons and evenings off the northern coast of Hispaniola into next week. The northern portion of a tropical wave will move through the waters south of 24N through Mon accompanied by scattered to numerous showers and thunderstorms, some of which may produce strong gusty winds and rough seas. $$ Christensen