000 AXNT20 KNHC 181648 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 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 1200 UTC surface analysis and satellite imagery through 1630 UTC. ...TROPICAL WAVE... An Atlantic Ocean tropical wave is along 57W from 21N southward, moving quickly W at 20-25 kt. No significant convection is noted with the tropical wave at this time. A Caribbean Sea tropical wave is along 77W, from eastern Cuba across Jamaica to far NW Colombia, moving W at 15-20 kt. Scattered moderate convection is from the coast of Panama north to 13N east of 81W to the coast of Colombia. Scattered showers are noted along the south coast of Jamaica. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the border of Senegal and The Gambia near 13N17W and continues to 10N33W to 10N56W. Scattered showers are along the monsoon trough. No segments of the ITCZ are analyzed at this time. GULF OF MEXICO... A surface trough extends from the central Florida Panhandle over the northern coastal Gulf waters to 28N92W. Scattered moderate convection is north of 28N between 84W and 94W. High pressure ridging extends across the basin from the subtropical Atlantic high. As a result, light to gentle E to SE winds prevail across the basin with 2-4 ft seas. Winds may be locally moderate in the Bay of Campeche. 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. Unstable atmospheric conditions with active weather will persist across the northern Gulf through Fri as an upper trough continues to the N of the basin. CARIBBEAN SEA... Please see the Tropical Waves section above for details on tropical waves and convection. Scattered moderate convection is from 11N to 14N west of 82W, including inland over Nicaragua. Moderate to fresh trades are noted in the central Caribbean, with 6-8 ft seas. Recent satellite scatterometer data indicates locally fresh winds along the south coast of Jamaica. In the eastern and western Caribbean, gentle to moderate trades prevail with 3-6 ft 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, with mainly moderate seas. Winds and seas will diminish slightly tonight through Sat as a pair of tropical waves move through the basin. The trade winds and associated seas will increase again Sat night into Mon as high pressure builds again in the wake of the tropical waves. ATLANTIC OCEAN... The tropical Atlantic is dominated by 1028 mb high pressure centered near 32N54W. Fresh trades, part of a trade wind surge near a tropical wave, has built seas to 7-8 ft from 16N to 25N between 50W and 65W. Elsewhere, satellite scatterometer data from this morning depicts gentle to moderate trades. Seas are 4-7 ft in open waters. 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 winds pulsing to strong during the late afternoon and evening off the northern coast of Hispaniola. $$ Mahoney/Adams