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