000 AXNT20 KNHC 171659 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Jul 17 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 1200 UTC surface analysis and satellite imagery through 1655 UTC. ...TROPICAL WAVE... A tropical wave in the central Atlantic has been repositioned farther west to near 49W, south of 21N, based on recent satellite imagery and tropical wave guidance. The wave is moving westward at 15 kt. The wave axis is embedded in dry Saharan air limiting the development of showers and thunderstorms. An eastern Caribbean tropical wave is along 70W, south of 21N, moving at 10-15 kt. A few showers are noted from 13N to 17N and between 65W and 69W. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of NW Mauritania near 21N17W and continues southwestward to 11N30W and to 09N52W. The ITCZ extends from 09N52W to 12N61W. Scattered showers are observed from 07N to 13N and east of 33W. Similar convection is present from 06N to 09N and between 42W and 46W. ...GULF OF MEXICO... A weak surface trough is along the northern Gulf waters, supporting scattered showers and isolated thunderstorms north of 25N. Generally dry conditions are present elsewhere. A 1018 mb high pressure system in the southern Mississippi Valley sustains light to gentle anticyclonic winds and slight seas across the basin. For the forecast, high pressure will extend from the western Atlantic into the northern Gulf of Mexico through the weekend, supporting moderate or weaker winds and mainly slight seas. ...CARIBBEAN SEA... Scattered showers and isolated thunderstorms associated with the eastern Pacific monsoon trough are affecting the waters north of Panama and Costa Rica, mainly south of 10N. A strong subtropical ridge positioned over the central Atlantic dominates the Caribbean Sea, supporting fresh to strong easterly trade winds across the central and SW Caribbean waters. A recent scatterometer satellite pass showed the strongest winds occurring off northern Colombia. Seas in these waters are 5-8 ft. A buoy near 15N75W is reporting wave heights near 8 ft. Elsewhere, moderate or weaker winds and slight to moderate seas are prevalent. For the forecast, the pressure gradient between an Atlantic high pressure ridge extending along roughly 30N and lower pressure across South America will continue to sustain fresh to strong trade winds over the central Caribbean before diminishing slightly Thu into Sat as a pair of tropical waves move through the basin. Trades will increase again Sun as high pressure builds again in the wake of the tropical waves. ...ATLANTIC OCEAN... The interaction between a surface trough located between Bermuda and Puerto Rico and an upper level low near 26N66W result in scattered showers north of 23N and between 58W and 68W. Moderate winds and seas are occurring in the area described. However, the strongest convection may produce gusty winds and higher seas. The rest of the basin is under the influence of a broad subtropical ridge centered over the central Atlantic. The pressure gradient between this ridge and lower pressures in the deep tropics support moderate to fresh easterly winds from 15N to 27N and between 40W and 65W. Seas in these waters are 5-8 ft. Farther east, moderate to fresh southerly winds are noted south of the monsoon trough and east of 30W. Seas in the area described are 4-7 ft. Strong to near gale-force winds and higher seas are occurring in the areas of the strong convection. Elsewhere, moderate or weaker winds and moderate seas prevail. For the forecast W of 55W, the Bermuda high pressure ridge will extend east to west along roughly 30N through Sun. This pattern will support moderate to fresh easterly winds south of 25N through Sun, with strong winds occasionally pulsing off the northern coast of Hispaniola. $$ Delgado