000 AXNT20 KNHC 151757 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Mon May 15 2023 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 WAVES... The first tropical wave of this hurricane season is reaching the coast of Sierra Leone and Liberia this afternoon. Coupling with modest convergent monsoonal winds, scattered moderate to isolated strong convection is seen from 03N to 07N between 12W and 18W. This wave will be labeled in the 18Z surface analysis. ...MONSOON TROUGH/ITCZ... A monsoon trough enters the Atlantic along the African coast near the Senegal-Gambia border, then curves southwestward to 10N20W. Refer to the Tropical Waves section above for convection south of the trough. An ITCZ extends westward from 04N21W across 03N30W to 03N40W. Scattered moderate convection is observed up to 150 nm along either side of the ITCZ. The eastern end of the East Pacific monsoon trough is creating widely scattered showers and isolated thunderstorms at the Caribbean waters near Costa Rica and Panama. ...GULF OF MEXICO... A surface trough reaches northwestward from the Bay of Campeche to northeastern Mexico. Aided by an upper-level trough in the vicinity, scattered showers and thunderstorms are flaring up off the Mexico and Texas coast. Another surface trough is triggering isolated thunderstorms at the central Gulf. Gentle to moderate NE to SE winds and seas at 3 to 4 ft are found over the western Gulf. Otherwise, a weak surface ridge extending southward from a 1021 mb high near the Mississippi-Alabama border is supporting light to gentle winds with 1 to 2 ft seas for the eastern Gulf, including the Florida Straits. For the forecast, gentle to moderate E to SE winds and moderate seas across the western Gulf will continue to diminish today. A ridge will remain in control of the weather pattern across the Gulf waters producing mainly light to gentle winds and slight seas beginning on Tue. Gentle to moderate westerly winds are expected over the northeastern Gulf Wed and Wed night as a cold front approaches the area. Gentle to moderate NE to E winds are forecast at night near and northwest of the Yucatan Peninsula through Fri night. ...CARIBBEAN SEA... Convergent trade winds are producing scattered shower and isolated thunderstorms at the northwestern basin, including the Gulf of Honduras and Mexico-Belize coast. Gentle to moderate NE to E trades and seas of 2 to 4 ft exist across the northwestern and southeastern basin. Moderate with locally fresh E to ESE trades and 4 to 7 ft seas prevail for the rest of the basin. For the forecast, gentle to moderate trades and slight to moderate seas are expected over the eastern and central basin, while light to gentle winds and slight seas will prevail in the northwestern basin. Winds are forecast to increase to between moderate and fresh across the south-central basin by Thu. ...ATLANTIC OCEAN... A broad surface trough is coupling with divergent winds aloft to generate scattered moderate convection just east of the Bahamas from 22N to 28N between 68W and 75W. A pre-frontal trough curves southwestward from east of Bermuda across 31N59W to 28N66W. Scattered showers and isolated thunderstorms are noted up to 50 nm along either side of this feature. An upper-level low near 26N20W is causing similar conditions south of the Canary Islands from 21N to 27W between the Sahara coast and 18W. Refer to the Monsoon Trough/ITCZ and Tropical Waves sections for additional weather in the Atlantic Basin. Gentle to moderate with locally fresh E to SE winds and 3 to 5 ft seas are seen near the surface trough from the central Bahamas northward to beyond 31N and west of 70W. The Atlantic Ridge extends southwestward from a 1030 mb Azores High across 31N40W to 24N70W. Light to gentle winds and seas at 3 to 4 ft are present up to 200 nm along either side of this ridge. To the south, moderate to fresh NE to ENE trades with 5 to 7 ft seas are evident from 05N to 18N between 40W and the Lesser Antilles/southeast Bahamas. Near the Canary Islands, Moderate to fresh with locally strong NNE trades and seas of 6 to 8 ft are found north of 22N between the Morrocco-Sahara coast and 40W. Farther south, gentle to moderate NNE to NE trades with 4 to 6 ft seas dominate from 09N to 22N between the central Africa coast and 35W. Light to gentle NE to SE and monsoonal winds and seas at 4 to 6 ft in mixed northerly and southerly swells prevail elsewhere in the Atlantic Basin. For the forecast, a weak cold front will move across the western Atlantic north of 25N through Tue, then exit the area by Tue night. A surface trough near the central Bahamas will dissipate by Tue night as high pressure builds across the area from the east, bringing gentle to moderate SE to S winds. A weak low pres is forecast to develop along a frontal boundary just off the southeastern U.S. by Wed, affecting the waters off northeastern Florida with moderate to fresh SW to W winds. $$ Forecaster Chan