AXNT20 KNHC 240752 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Wed Apr 24 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 0730 UTC. ...SPECIAL FEATURES... Central Atlantic Significant Swell: A 1010 mb low pressure near 26N35W will slowly drift southwestward through Thu, opening up to a trough Fri. A large area of fresh to near gale-force NE winds has generated large seas with heights of 12 to 13 ft N of 25N between 35W and 42W. Seas of 8 ft or greater cover the waters N of 22N between 30W and 46W. Scattered showers and thunderstorms are possible within 30 nm of the low center per recent satellite imagery. Peak seas will subside to less than 12 ft through this evening as the low weakens and gradually opens up to a trough. Meanwhile, winds will diminish to 20 kt or less by Thu evening. Please read the latest High Seas Forecast issued by the National Hurricane Center at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. Strong Thunderstorms With Heavy Rainfall in Hispaniola: A persistent surface trough extending southwestward from 27N61W to western side of Puerto Rico is providing moist southerly flow across Hispaniola. Together with a pronounced mid to upper-level trough in the vicinity, strong thunderstorms are likely during the afternoon and early evening hours over and near Hispaniola today and Thu. These thunderstorms are capable of producing heavy downpours, increasing the chance for flash flooding, especially in hilly terrains and low-lying areas. Please refer to local weather service offices for more details on this event. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 08N13W extending southwestward to 02N16W. The ITCZ continues from 02N16W to 02S21W to 00N36W to just NE of the coast of Brazil near 00N44W. Scattered moderate isolated strong convection is noted from 02N to 07N between 15W and 23W, and from 00N to 03N between 28W and 41W. ...GULF OF MEXICO... A surface ridge extends from E to W just N of the basin across the southeastern United States. Mainly gentle to moderate E to SE winds prevail across the basin, locally fresh W of the Yucatan Peninsula. Seas are 1 to 3 ft across the NE half of the basin, and 3 to 5 ft across the SW half of the basin, up to 6 ft near the Straits of Florida where hazardous conditions are possible. For the forecast, high pressure just N of the basin will support mainly gentle to moderate E winds in the NE half of the Gulf, and moderate to fresh SE winds in the SW half of the Gulf through Thu. The pressure gradient will tighten over the Gulf starting Thu night, increasing E to SE winds to fresh to strong across the whole basin through Sun night. Meanwhile, winds will pulse to fresh to strong W of the Yucatan each evening. ...CARIBBEAN SEA... Please read the Special Features section about strong thunderstorms and the potential heavy rainfall across Hispaniola. Gentle to moderate trades are N of 15N, except fresh near the Windward Passage and in the Lee of Cuba, with moderate to fresh trades S of 15N, locally strong near Colombia. Seas are 2 to 5 ft across the basin, locally 6 ft in the S-central Caribbean. For the forecast, high pressure will build N of the area supporting fresh to locally strong winds just N of Colombia, through the Windward Passage, and in the lee of Cuba today through Thu. Looking ahead, further building of the high on starting on Fri will also force fresh to strong trades in the Gulf of Honduras and just S of Hispaniola through the weekend. ...ATLANTIC OCEAN... Please read the Special Features section about Significant Swell in the Central Atlantic, and about strong thunderstorms and potential for heavy rainfall across Hispaniola. A cold front extends from 31N61W to 23N72W. High pressure, 1021 mb, is centered W of the front near 30N79W. Gentle to moderate winds prevail W of the front, except light to gentle near the high center. Seas are elevated W of the front, 6 to 9 ft in northerly swell. Away from the low discussed above, moderate to fresh trades prevail E of the front to 40W, along with 4 to 7 ft seas. Gentle to moderate winds are E of 40W away from the low, except moderate to fresh N of 20N between the coast of Africa and 20W. Seas are 3 to 6 ft away from the low. For the forecast west of 55W, the front will reach from 31N59W to the Turks and Caicos Islands this evening where it will stall and dissipate to a remnant trough. Associated northerly swell of 8 ft or greater will subside by this evening. Fairly tranquil conditions are forecast Thu and Thu night. Looking ahead, a new cold front will merge with the trough and progress eastward, reaching 31N57W to E Cuba on Sat morning, and then 25N55W to Hispaniola on Sun morning. Swell will push S of 31N with the front, resulting in building seas. A strengthening Bermuda High should cause widespread fresh to strong N to E winds W of the front beginning Fri evening through Sun evening. $$ Lewitsky