242 AXNT20 KNHC 180518 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0615 UTC Sun May 18 2025 Tropical Weather Discussion for North America, Central America Gulf of America, 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 0000 UTC surface analysis and satellite imagery through 0420 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 11N15W, then curves southwestward to 05.5N23W, where it transitions to ITCZ, and continues west-southwestward to the east coast of Brazil near 02N51. Scattered strong convection is occurring across the nearshore waters of western Africa, north of 03N and between 03W and 14W. Scattered moderate isolated strong convection is observed between 01N and 06.5N between 18W and 42W. Scattered moderate to strong convection is noted S of 03N between 42W and 51W, and from 05N to 09.5N between 50W and 61W. ...GULF OF AMERICA... Broad surface ridging extends from the central Atlantic westward to central Florida and then weakly across the eastern Gulf, where a new 1017 mb high center has formed near 26N83W. The pressure between this ridge and low pressure across central Mexico is supporting moderate to fresh E to SE winds across most of the south and southwest Gulf, and moderate SE to S winds across northwest portions. Recent satellite scatterometer data captured fresh to locally strong E to NE winds across the waters off the NW Yucatan Peninsula. Seas are 3 to 4 ft across much of the basin, and 4 to 5 ft off the NW Yucatan and across western portions. Seas are 1 to 2 ft across the NE Gulf and along the Florida west coast. No convection is noted over the basin at this time, while strong thunderstorms continue across large portions of southern Texas Otherwise, smoke from agricultural fires over southeastern Mexico continues to create hazy conditions at the west-central and southwestern Gulf, including the Bay of Campeche. For the forecast, the pressure gradient between high pressure over the eastern Gulf and relatively lower pressure in Texas and eastern Mexico will maintain moderate to fresh SE winds and moderate seas across the western Gulf through Tue. Pulsing fresh to strong E winds are likely each afternoon and evening through Tue night, north of the Yucatan Peninsula as a trough develops daily and drifts westward. Smoke from agricultural fires in southeastern Mexico will sustain hazy conditions at the west- central and southwestern Gulf most likely through the period. ...CARIBBEAN SEA... High pressure of 1026 mb centered near 30N44W extends a broad ridge westward to 60W, and then become a narrow ridge westward to central Florida. A deep-layered upper trough is over the Atlantic along about 65W-66W and extends S-SW across the Mona Passage and into the central Caribbean. A weak surface trough has formed in the NE Caribbean along 63W, where the upper trough is supporting scattered moderate to strong convection along and E of the surface trough extending northeastward across the Leeward Islands and into the adjacent Atlantic. Moderate to locally fresh trade winds prevail across the basin east of 75W, through the Windward Passage, and across the Gulf of Honduras, where seas are 4 to 5 ft. Gentle to moderate winds are elsewhere with seas of 2 to 4 ft. For the forecast, a modest ridge will remain north of the basin through Mon to generally maintain current conditions. Fresh to strong E to SE winds will pulse in the Gulf of Honduras during late afternoons and nights through the period. Moderate to fresh trades, rough seas and active thunderstorms will persist over the Atlantic waters near and east of the Lesser Antilles through Sun night. Increasing trades along with building seas are expected to shift into the eastern part of the basin Sun night. These conditions will then shift westward across the central and southwestern basin through next week as high pressure strengthens north of the area. ...ATLANTIC OCEAN... High pressure of 1026 mb centered near 30N44W extends a broad ridge westward to 60W, and then become a narrow ridge westward to central Florida. A deep-layered upper trough is over the Atlantic along about 65W-66W and extends S-SW across the Mona Passage and into the central Caribbean. A surface trough continues just east of this upper trough, extending from near 27N62W to near the British Virgin Islands. Scattered moderate isolated strong thunderstorms are occurring along and east of the trough to 59W, supported by the upper trough, from the Leeward Islands north to 27N. West of the surface trough, gentle to moderate anticyclonic winds prevail, with seas of 2 to 4 ft. East of this surface trough, the ridge is supporting fresh to locally strong easterly trade winds from the Cabo Verde Islands to the Lesser Antilles. Seas here are 6 to 9 ft south of 25N, and 4 to 6 ft north of 25N. An old frontal trough is seen lingering from 31N16W to 20N37W, with fresh NE winds to the north of this feature, and seas 6 to 9 ft. Farther east, fresh to locally strong northerly winds are along the African west coast north of 14N, where seas are 5 to 7 ft. For the forecast west of 55W, a mid to upper level trough and an associated surface trough that extends from 26N62W to 20N65W is resulting in unsettled weather conditions, with moderate to fresh winds and moderate seas primarily over the waters S of about 27N between 58W and 64W. These conditions should gradually improve through early Mon as they shift ENE. Meanwhile, broad high pressure extending west-southwestward from the central Atlantic to Florida will support gentle winds south of 28N. Moderate to fresh northeast to east winds will pulse north of Hispaniola and in the Windward Passage each night into next week. In the long term, fresh to strong southwesterly winds and building seas are expected off of northeastern Florida and northeast of the Bahamas around the middle of next week, in response to a late season cold front that will move off the southeastern United States coast. This front may be accompanied by scattered showers and thunderstorms. Farther south, moderate to fresh northeast to east winds will pulse north of Hispaniola and in the Windward Passage each night into next week. $$ Stripling