000 AXNT20 KNHC 181020 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Thu Jul 18 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...TROPICAL WAVE... An Atlantic Ocean tropical wave is along 53W from 20N southward, moving W at 10 to 15 kt. Scattered moderate convection is noted within about 300 nm on either side of the wave axis, S of 10N. A Caribbean Sea tropical wave is along 75W, from the Windward Passage to Colombia, moving W at 10 to 15 kt. Numerous moderate to isolated strong convection is noted near the coast along the Colombia-Venezuela. Scattered moderate convection is noted in the eastern Caribbean behind the wave for about 240 nm. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal plains of Mauritania at 17N16W to 12N34W to 10N49W to 11N55W. Scattered moderate convection is noted within 180 nm S of the monsoon trough. ...GULF OF MEXICO... A surface ridge extends from an Atlantic high pressure center E of Bermuda across the central Gulf of Mexico. This is preventing any significant convection and leading to mainly gentle SE winds with seas of 2 ft or less. Some moderate SW winds and seas to 3 ft are in the eastern Bay of Campeche early this morning. For the forecast, High pressure will extend from the western Atlantic into the northern Gulf of Mexico through early next week, supporting mainly gentle winds and slight seas. ...CARIBBEAN SEA... See Tropical Waves section above for details on convection in the central and eastern basin. The eastern extension of the East Pacific monsoon trough along 09W continues to the Colombia coast. Numerous moderate to isolated strong convection is ongoing along and south of this trough to 75W. Fresh to strong NE to E winds are S of 18N between 70W and 76W. Moderate to locally high seas are present in this same area. Eastern parts of the basin have moderate to fresh trades with moderate seas. For the remainder of the basin, winds are mainly gentle with light seas. For the forecast, the pressure gradient between an Atlantic high pressure ridge extending along roughly 30N and lower pressure across South America is supporting fresh to locally strong trade winds over the central Caribbean, along with mainly moderate seas. Winds and seas will diminish slightly through Sat as a pair of tropical waves move through the basin. The tradewinds and associated seas will increase again Sat night into Mon as high pressure builds again in the wake of the tropical waves. ...ATLANTIC OCEAN... An upper level trough along 65W is leading to scattered moderate convection between 60W and the Bahamas. The remainder of convection in the basin is associated with a tropical wave and the monsoon trough and is described in the sections above. A broad swatch of fresh trades extends across the entire basin from 15N to 25N, with moderate seas prevail. Elsewhere, winds and seas are moderate or less. The basin is dominated by a broad surface ridge with an axis around 30N. For the forecast W of 55W, the Bermuda high pressure ridge will extend east to west along roughly 30N through Mon night. This pattern will support moderate to fresh easterly winds south of 25N, with strong winds occasionally pulsing off the northern coast of Hispaniola. $$ Konarik