443 AXNT20 KNHC 172352 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 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 1800 UTC surface analysis and satellite imagery through 2350 UTC. ...TROPICAL WAVE... A tropical wave is in the central Atlantic extending from 05N to 20N with axis near 50W, moving westward at 15 kt. The wave is embedded in dry Saharan air, thus limiting the development of showers and thunderstorms. A tropical wave is in the central Caribbean with axis S of 21N near 71W, moving west at 10-15 kt. Strong vertical shear is hindering the development of convection at the time. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of NW Mauritania near 19N16W and continues southwestward to 10N35W to 10N54W. The ITCZ extends from 10N54W to 11N61W. Scattered moderate convection is from 07N to 14N between 13W and 32W. ...GULF OF MEXICO... A generally weak pressure gradient prevails across the Gulf of Mexico under the influence of the Bermuda High and associated ridge. This pattern is supporting light to gentle variable winds and slight seas, except for moderate to locally fresh NE to E winds off the coast of western Yucatan into the Bay of Campeche. Otherwise, moisture inflow from the Caribbean and upper level divergence continue to fuel scattered showers and thunderstorms across the north-central and northeast basin where also a surface trough is analized. For the forecast, high pressure will extend from the western Atlantic into the northern Gulf of Mexico into early next week, supporting gentle to moderate winds and slight seas. ...CARIBBEAN SEA... The pressure gradient between an Atlantic high pressure ridge extending along roughly 30N and lower pressure across South America are supporting fresh to strong trade winds over the central Caribbean, along with moderate to rough seas. Over the eastern basin, trade winds are gentle to moderate while in the NW Caribbean winds are light to gentle. Otherwise, scattered heavy showers and tstms are ongoing over the offshore zones of Panama and Costa Rica in association with the E Pacific extension of the monsoon trough. Scattered showers and tstms are also ongoing over Puerto Rico and Dominican Republic adjacent waters. For the forecast, winds and seas will diminish slightly across the central Caribbean Thu into Sat as a pair of tropical waves move through the basin. The tradewinds and associated seas will increase again Sun and Mon as high pressure builds again in the wake of the tropical waves. ...ATLANTIC OCEAN... The subtropical Atlantic waters remain under the influence of the Bermuda High and associated ridge, which is mainly supporting gentle to moderate NE to E winds and moderate seas, except between 44W and 60W where the passage of a tropical wave tightens the pressure gradient, thus freshening the winds. In this region, seas are 7-8 ft. Otherwise, a middle-level short-wave trough supports heavy showers and scattered tstms across the Bahamas offshore waters between 60W and 68W. For the forecast W of 55W, the Bermuda high pressure ridge will extend east to west along roughly 30N through Mon. This pattern will support moderate to fresh easterly winds south of 25N through Mon, with strong winds occasionally pulsing off the northern coast of Hispaniola. $$ Ramos/Adams