000 AXNT20 KNHC 182322 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Mon Aug 19 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. ...TROPICAL WAVES... A tropical wave is analyzed along 39W from 05N to 21N, moving west at 10 to 15 kt. Scattered moderate convection is observed where the wave meets the monsoon trough from 05N to 10N between 35W and 40W. A tropical wave is passing through the Lesser Antilles. Its axis is along 60W S of 20N into northern Guyana, moving west at 15 to 20 kt. Scattered showers and isolated thunderstorms are noted mainly across the Windward Islands and adjacent waters. A tropical wave is moving across the central Caribbean and extends from the Windward Passage to northern Colombia. Its axis is along 75W, moving west at 10 to 15 kt. The wave is helping to induce showers and thunderstorms across the mentioned area. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean through the coast of Mauritania near 18N16W, the continues SW to near 12N30W and westward to near 11N54W. In addition to the convection associated with the tropical wave, scattered moderate convection is seen from 05N to 10N between 26W and 35W. ...GULF OF MEXICO... A surface trough extends westward from the Florida Keys across the central Gulf to near 25N94W. Showers and thunderstorms are noted along the trough axis affecting parts of the Florida Keys and South Florida. Otherwise, a very weak pressure gradient prevails across the Gulf of Mexico, which is supporting light to gentle winds and seas of 1 to 3 ft across the basin. For the forecast, a weak pressure pattern across the Gulf will support mainly gentle to locally moderate breezes and slight seas through Fri night. A weak cold front is 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... Two tropical waves are moving across the basin. Please refer to the Tropical Waves section above for more information. Convection has flared-up again across the Greater Antilles and parts of Central America. Recent scatterometer data indicate fresh to strong E to SE winds in the vicinity of the ABC Islands and to the N to about 15N. Moderate to locally fresh trades dominate the remainder of the east and central Caribbean while light to gentle winds prevail over the NW part of the basin. Seas are generally 4 to 6 ft, except 2 to 4 ft over the NW Caribbean. For the forecast, high pressure will prevail 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 Fri night, increasing to fresh to strong speeds in the south-central region tonight through Tue night. Moderate to rough seas are forecast for the south- central basin. Elsewhere, gentle to moderate winds are expected along with slight to moderate wave heights. ...ATLANTIC OCEAN... Ernesto is a hurricane again located well N of the forecast region. It is centered near 37.1N 62.3W at 18/2100 UTC or 450 nm S of Halifax Nova Scotia, moving NNE at 15 kt. Estimated minimum central pressure is 977 mb. Maximum sustained wind speed is 65 kt with gusts to 80 kt. Swells generated by Ernesto are affecting portions of the Bahamas, Bermuda, the east coast of the United States, and Atlantic Canada. Life-threatening surf and rip current conditions are likely to continue in these areas during the next couple of days. A ridge, associated with a 1027 mb high pressure located near the Azores, dominates most of the forecast region, and extends into the NE Caribbean. A surface trough crosses the NW Bahamas generating some shower activity. Under the influence of the ridge, mainly gentle to moderate winds are noted, except between the Canary Islands where scatterometer data show fresh to strong N winds. Fresh NW to N winds are seen near the Western Sahara/ Mauritania border. Seas of 8 to 9 ft, associated with fresh to strong northerly winds N of 30N, are reaching the Canary Islands. A large area of 8 to 10 ft, in long period S swell, is observed SE of the Cabo Verde Islands. An altimeter pass confirmed the present of these sea heights. Elsewhere, mostly seas of 4 to 6 ft prevail, except N of 28N between 55W and 70W where seas of 8 to 10 ft generating by Ernesto are still affecting these waters. For the forecast west of 55W, large swells across the forecast waters generated by Ernesto will slowly subside through early Mon. Expect moderate to fresh SW winds off northeast Florida tonight into Mon, ahead of a weak cold front that will move into the area late tonight. The front will briefly stall Mon night and weaken through mid week. $$ GR