000 AXNT20 KNHC 162349 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sat Aug 17 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 centered near 31.0N 65.2W at 16/0000 UTC or 80 nm SSW of Bermuda, moving NE at 11 kt. Estimated minimum central pressure is 969 mb. Maximum sustained wind speed is 85 kt with gusts to 105 kt. Peak seas are 42 ft near the center. Numerous moderate to strong convection is seen within about 90 nm N semicircle and 75 nm SE quadrant of center. On the forecast track, the center of Ernesto is expected to pass near or over Bermuda tomorrow morning. Some gradual weakening is forecast over the next day or so, though some re-intensification is possible by early next week. Swells generated by Ernesto are affecting portions of the Turks and Caicos Islands, the Bahamas, and Bermuda. Swells are also beginning to affect the east coast of the United States and will likely reach portions of Atlantic Canada by late Saturday. These swells are likely to cause life- threatening surf and rip current conditions. Please consult products from your local weather office, and stay out of the water if advised by lifeguards. Ernesto is expected to produce total rain accumulations of 6 to 9 inches or 150 to 225 mm in Bermuda. This rainfall will likely result in considerable life- threatening flash flooding, especially in low-lying areas on the island. 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 just W of the Cabo Verde Islands with axis along 25W from 05N to 20N. It is moving west at around 15 kt. Scattered moderate convection is from 05N to 10N between 20W and 30W. A second tropical wave is along 46W from 05N to 20N, moving west at 10 to 15 kt. Scattered moderate convection is seen near the southern end of the wave axis from 05N to 09N between 40W and 46W. A tropical wave is moving across the Lesser Antilles producing scattered showers and thunderstorms, mainly over the Leeward Islands. Its axis is along 61W, and moving west at 10 to 15 kt. The wave will move across the eastern Caribbean tonight and Sat. Moisture associated with this system is forecast to reach Puerto Rico and the Virgin Islands on Sat. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic from the coast of Mauritania near 20N16W, then continues SW to 12N30W and westward to 12N50W. Most of the convective activity is related to the tropical wave. ...GULF OF MEXICO... A surface trough is analyzed from the southern tip of the Florida Peninsula and the Florida Keys west and northwestward to near SE Louisiana. Scattered showers and thunderstorms are along the trough axis affecting mainly South Florida and the Florida Keys. A 1017 mb high pressure remains over the NW Gulf near 29N93W. Under this weather pattern, mainly light and variable winds and seas of 1 to 3 ft are noted, with the exception of gentle to moderate NE to E winds and seas of 3 to 4 ft over the NE Gulf and E of the trough. For the forecast, a weak pressure pattern will continue across the Gulf through Sun, supporting gentle to moderate winds and slight seas. Looking ahead, light northerly winds may briefly follow a weak cold front expected to move into the northern Gulf Mon. The front will stall and dissipate through mid week. ...CARIBBEAN SEA... The most recent satellite derived wind data provide observations of moderate to fresh E to SE winds from the ABC Islands to about 15N, and S of 12N to the coast of Venezuela between 66W and 68W. Gentle to moderate trades prevail elsewhere across the east and central Caribbean. Light to gentle winds dominate the NW part of the basin. Seas are slight to moderate basin-wide, highest in the central Caribbean. Showers and thunderstorms are flaring up over the Greater Antilles due to local effects. Similar convective activity is seen over parts of Nicaragua under strong upper-level winds. A tropical is affecting the Lesser Antilles. Please, see the Tropical Waves section for more details. For the forecast, high pressure is building north of the region over the western Atlantic. This pattern will support fresh to strong trade winds over the south-central Caribbean with moderate to rough seas, and gentle to moderate winds elsewhere with slight to moderate wave heights. ...ATLANTIC OCEAN... Please see the Special Features section for more information about Hurricane Ernesto. The fresh to strong winds associated with the outer periphery of Hurricane Ernesto cover roughly the waters N of 23N between 60W and 73W. This has produced a large wave field moving in synch with Ernesto, with seas 8 ft of greater dominating the waters N of 23N W of 60W and NE of the Bahamas. The remainder of the Atlantic forecast waters is under the influence of a ridge anchored by a 1027 mb high pressure located near the Azores. The pressure gradient between the ridge and lower pressure over NW Africa supports moderate to fresh NE winds E of 30W with seas of 6 to 9 ft, and gentle to moderate NE to E winds W of 30W and E of Hurricane Ernesto with seas of 4 to 6 ft. For the forecast west of 55W, Hurricane Ernesto will be N of area near 31.9N 65.1W Sat morning, then continue to move well north of the region through the early part of the week, before weakening late Tue. Large swells generated by Ernesto will spread westward to Bahamas and the southeast United States coast including Florida. Expect fresh SW winds off northeast Florida Sun and Mon, ahead of a weak cold front that will move into the area early in the week, then stall and weaken through mid week. Conditions will gradually improve elsewhere across the basin through the early part of the week in the wake of Ernesto. $$ GR