000 WTNT45 KNHC 200231 TCDAT5 Hurricane Ernesto Discussion Number 34 NWS National Hurricane Center Miami FL AL052024 1100 PM AST Mon Aug 19 2024 Satellite imagery shows that the convective structure of Ernesto is decaying due to increasing shear and passage over colder water, with most of the remaining convection now in the northeastern quadrant. However, Canadian radar shows the remaining convection still has a good tropical cyclone banding pattern. Satellite intensity estimates were mostly near 75 kt at 00Z, and based on the loss of organization since that time the initial intensity is decreased to 70 kt. Ernesto should continue steady to rapid weakening due to shear and cold water. The new intensity forecast has the cyclone losing its remaining convection and becoming a post-tropical low by 24 h. However, this could be generous, and the system could become post-tropical at any time. After 24 h, Ernesto is going to become involved with a large baroclinic low developing near Iceland, and as this occurs it is likely to develop or merge with a frontal zone to become extratropical. The system is expected to degenerate to a trough on the south side of the larger low by 48 h. The hurricane is now accelerating northeastward with the initial motion of 050/30 kt. The strong flow between an approaching mid- to upper-level trough over the eastern U.S. and a ridge over the subtropical central Atlantic should cause the cyclone to accelerate even more during the next 24 h, and a rapid east-northeastward motion should continue as the baroclinic low becomes the predominant steering influence. The NHC track forecast remains near the middle of the tightly clustered models and has no significant change since the previous advisory. Key Messages: 1. The effects of swells generated by Ernesto on the coasts of Bermuda, the northeast U.S., and Atlantic Canada should diminish during the next day or so. Until then, beach goers should be aware that there still could be a significant risk of life-threatening surf and rip currents and should stay out of the water if advised by lifeguards. 2. Ernesto will likely bring some wind, wave, and rain impacts to portions of southeastern Newfoundland during the next several hours. Breaking waves could bring the possibility of coastal flooding, particularly along southwest-facing shorelines from Bunin east to Avalon regions. For additional impact specific information, please see statements issued by the Canadian Hurricane Centre. FORECAST POSITIONS AND MAX WINDS INIT 20/0300Z 45.7N 53.1W 70 KT 80 MPH 12H 20/1200Z 48.0N 47.2W 60 KT 70 MPH 24H 21/0000Z 50.6N 36.3W 50 KT 60 MPH...POST-TROPICAL 36H 21/1200Z 52.8N 24.1W 45 KT 50 MPH...POST-TROP/EXTRATROP 48H 22/0000Z...POST-TROP/EXTRATROP $$ Forecaster Beven