Official Discussion issued by the National Hurricane Center
Ernesto (AL052024) DATA RELEASED: 8/20/2024 9:00:00 AM UTC
Copy of official data Hurricane Ernesto Discussion Number 35 NWS National Hurricane Center Miami FL AL052024 500 AM AST Tue Aug 20 2024 Increasingly strong westerly vertical wind shear is affecting the cyclone, displacing most of the remaining deep convection to the east of the low-level center. The system's cloud pattern is already taking on a less tropical-looking appearance, making intensity estimates via the Dvorak technique somewhat problematic. However, a couple of ship reports of winds of 58 and 51 kt to the east of the center indicate that Ernesto is still near hurricane strength. Thus, the advisory intensity is set at 65 kt. The hurricane has been accelerating northeastward and the initial motion estimate is 050/31 kt. Ernesto is embedded within a strong deep-layer flow between a large trough over the northeastern U.S. and a ridge over the central subtropical Atlantic. In a day or so, an even faster motion toward the northeast and east-northeast is likely as the cyclone comes more under the influence of a large deep-layer cyclone over the northeastern Atlantic. The official track forecast is close to the previous NHC prediction, and follows the multi-model consensus solution. Continued weakening is likely as Ernesto moves over cold water and remains under the influence of strong shear. Based on current trends and simulated satellite imagery from the global models, the system's deep convection should be disrupted to the point that Ernesto will have become a post-tropical cyclone in about 12 hours. In 24 hours, the guidance shows a frontal appearance indicating extratropical transition. In 36 hours or so, Ernesto is predicted to open up into a trough over the northeastern Atlantic. 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. FORECAST POSITIONS AND MAX WINDS INIT 20/0900Z 47.3N 50.0W 65 KT 75 MPH 12H 20/1800Z 49.5N 42.0W 55 KT 65 MPH...POST-TROPICAL 24H 21/0600Z 52.0N 30.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 36H 21/1800Z...DISSIPATED $$ Forecaster Pasch |