000 AXNT20 KNHC 172339 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sun Aug 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURES... Hurricane Ernesto is N of the forecast area. It is centered near 33.5N 63.7W at 17/0000 UTC or 90 nm NE of Bermuda, moving NNE at 5 kt. Estimated minimum central pressure is 976 mb. Maximum sustained wind speed is 65 kt with gusts to 80 kt. Fresh to strong winds and seas of 10 to 15 ft associated with the outer periphery of Ernesto are still affecting the forecast waters mainly north of 27N between 58W and 68W. Elsewhere, seas of 8 to 11 ft in mixed swell generated by Ernesto dominate the forecast waters N of 26N between 55W and 75W. On the forecast track, the center of Ernesto will slowly move away from Bermuda through tonight and pass near southeastern Newfoundland late Monday and Monday night. No significant change in strength is forecast during the next 48 hours, and Ernesto should remain near or at hurricane strength through Monday. The cyclone will likely become post-tropical near southeastern Newfoundland by Monday night or Tuesday morning. Swells generated by Ernesto are affecting portions of the Bahamas, Bermuda, the east coast of the United States, and Atlantic Canada today. Life- threatening surf and rip current conditions are likely in these areas during the next couple of days. Please consult products from your local weather office, and stay out of the water if advised by lifeguards. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Ernesto NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave is west of the Cabo Verde Islands. Its axis is along 28W from 05N to 21N moving W at 5 to 10 kt. Convection is limited near the wave axis. A tropical wave is along 53W/54W from 05N to 20N moving W at 15 to 20 kt. No significant convection is noted at this time. A tropical wave is moving across the Caribbean Sea. Its axis in near 70W and extends from Dominican Republic to western Venezuela, moving west at 15 to 20 kt. The wave is enhancing convection across Puerto Rico and parts of Dominican Republic. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean through the coast of Mauritania near 19N16W, then continues SW to 12N30W and westward to 12N51W. Isolated to scattered moderate convection is within about 210-240 nm S of the monsoon trough. GULF OF MEXICO... A surface trough extending from the Straits of Florida to the north-central Gulf of Mexico is producing a narrow band of showers with embedded thunderstorms. Moisture associated with this trough will continue to affect the Florida Keys and South Florida on Sun, keeping the likelihood of showers and thunderstorms. A weak pressure gradient dominates the Gulf waters allowing for light to gentle winds and slight seas across the basin, except N of the surface trough over the eastern Gulf and E of 87W where scatterometer data indicate mainly moderate NE winds. For the forecast, the weak pressure pattern will continue across the Gulf through Sun, supporting gentle to moderate winds and slight seas. Moderate to fresh SW winds will develop over the far NE Gulf Sun evening ahead of a weak cold front forecast to move into the NE Gulf early on Mon. The front will stall briefly Mon night and then move E of the area Tue afternoon. CARIBBEAN SEA... A tropical wave is moving across the basin. Please see the Tropical Waves section above for more details. Satellite derived wind data provide observations of moderate to fresh winds over the south-central Caribbean and gentle to moderate trades across the remainder of the east and central parts of the basin with seas of 3 to 6 ft. Light to gentle winds and seas of 1 to 3 ft are over the NW Caribbean. Daytime heating and local sea breezes combined with the available moisture are resulting in scattered showers and thunderstorms across the Greater Antilles. Scattered to numerous showers and thunderstorms are affecting parts of Central America, especially northern Honduras and Nicaragua. For the forecast, high pressure will build N of the area. The pressure gradient between the area of high pressure and low pressure over NW Colombia will support moderate to fresh trades over the central Caribbean through Thu, increasing to fresh to strong speeds in the south-central region Sun through Tue night. Moderate to rough seas are forecast for the south-central Caribbean. Elsewhere, gentle to moderate winds are expected along with slight to moderate seas. ATLANTIC OCEAN... Hurricane Ernesto continues to move away from the Atlantic forecast waters. Please, see the Special Features section for more details. Seas 8 ft or greater in mixed swell, associated with Hurricane Ernesto, continue to impact offshore waters in the W and central Atlantic north of 26N between 55W and 75W. A surface trough extends from 30N61W across the central Bahamas and the Straits of Florida into the eastern Gulf of Mexico. Scattered to numerous showers and thunderstorms are along the trough axis over the central Bahamas and the Straits of Florida. High pressure of 1026 mb located near the Azores dominates the remainder of the Atlantic forecast region. Gentle to moderate winds are noted under the influence of this system. Fresh to strong S to SW winds are observed S of the monsoon trough between 20W and 30W. These winds are related to a broad cyclonic circulation associated with a tropical wave. For the forecast west of 55W, Hurricane Ernesto will continue to move further from the area. Large swells generated by Ernesto will spread westward to the Bahamas and the southeast United States coast through Mon. Expect moderate to fresh SW winds off northeast Florida late Sun into Mon, ahead of a weak cold front that will move into the area Sun night, then briefly stall Mon night and weaken through mid week. $$ GR