000 AXNT20 KNHC 290916 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Fri Jul 29 2022 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 0900 UTC. ...TROPICAL WAVES... A tropical wave is along 19W, south of 20N based on satellite imagery, Hovmoller diagram and wave diagnostic data. The wave is moving W at 15-20 kt. No deep convection is associated with this feature as it is embedded in a dry and dusty Saharan airmass. A central Atlantic tropical wave has its axis along 45W, south of 20N, moving W at 15-20 kt. Scattered moderate convection is near the southern portion of the wave axis, from 04N to 06N between 45W and 47W. The northern portion is surrounded by a dry and dusty Saharan airmass. Another central Atlantic tropical wave has its axis along 58W, south of 22N and moving W near 15 kt. Scattered moderate convection is noted from 17N to 20N between 55W and 58W. ...MONSOON TROUGH/ITCZ... The monsoon trough reaches the Atlantic through the coast of Mauritania near 20N16W to 06N40W to 06N48W. The ITCZ extends from 06N48W to 06N54W to the coast of Guyana near 06N57W. Scattered moderate convection is observed from 06N to 08N and between 28W and 32W. The eastern end of the East Pacific monsoon trough reaches across the southwest Caribbean from near Cartagena, Colombia to Limon, Costa Rica. A few showers and thunderstorms are noted from 12N78W. ...GULF OF MEXICO... A sharp upper trough extending from an upper low over Cuba westward to the northwest Gulf has been supporting clusters of showers and thunderstorms over the Yucatan Channel during the late evening, but these have dissipated over the early morning hours. Another upper low is centered over north-central Mexico, supporting a small area of showers and thunderstorms over the western Gulf near Tampico. Weak ridging across the northern Gulf is maintaining light to gentle breezes and 1 to 2 ft seas over the northeast Gulf, with moderate SE winds and 2 to 4 ft seas across the northwest Gulf. Farther south, moderate to fresh E winds and 3 to 5 ft seas are evident. For the forecast, weak high pressure extending across the northern Gulf will support gentle to moderate winds and slight seas across most of the Gulf through early next week. The exception will be the Bay of Campeche, where fresh to strong easterly winds will pulse over the next several nights due to a trough that develops over the Yucatan Peninsula in the evenings and moves westward overnight. ...CARIBBEAN SEA... An upper level low over central Cuba is supporting several clusters of showers and thunderstorms from the Windward Passage to near Grand Cayman to off western Cuba. No significant shower and thunderstorm activity is observed elsewhere. Weak ridging north of the area is maintaining mostly moderate to fresh trade winds across the eastern and central Caribbean, with 4 to 6 ft seas. Gentle to moderate E winds are evident over the northwest Caribbean, where seas are 3 to 5 ft. A scatterometer satellite pass from yesterday evening indicated fresh to strong NE to E winds reaching the northern approaches to the Windward Passage. The same scatterometer pass did not show strong winds pulsing off Colombia at the time of the pass, but subsequent ship observations indicated 25 to 30 kt pulsing off Colombia during the early morning. For the forecast, moderate to fresh winds and slight to moderate seas are expected across the area through late Sun, except for pulsing fresh winds every evening over the waters off Colombia. Looking ahead, winds and seas will build over the south-central Caribbean early next week following a tropical wave moving across the basin. ...ATLANTIC OCEAN... A 1022 mb high is centered near 29N67W and anchors the subtropical ridge along 29N between 55W and the coast of northeast Florida. A surface trough extends from 28N53W to 18N56W, moving west at 10 to 15 kt. A scatterometer satellite pass from earlier in the evening indicated fresh to strong winds off the northern coast of Hispaniola, reaching into the northern approaches of the Windward Passage. Seas are estimated to be 5 to 7 ft off Hispaniola in this area. Elsewhere, the ridge is supporting moderate to fresh E winds south of 25N and west of 55W with 4 to 6 ft seas in E swell, and light to gentle breezes with 3 to 5 ft seas north of 25N and west of 55W. Farther east, 6 to 7 ft seas and moderate to fresh winds are noted from 18N to 28N between 35W and 50W, on the northern edge of the tropical wave near 45W. Moderate to occasionally fresh trade winds and 4 to 6 ft are evident elsewhere south of 31N, except strong NE winds and 7 to 10 ft seas off northwest Africa, north of 18N. Saharan dust covers much of the eastern Atlantic, mainly north of 20N and east of 30W. For the forecast west of 55W, a high pressure ridge along 29N will change little through Mon night, then shift slightly south Tue and Tue night as a cold front approaches the southeastern U.S. Fresh to strong winds will pulse north of Hispaniola and in the approaches to the Windward Passage in the late afternoons and during the overnight hours into early next week. $$ Christensen