Official Discussion issued by the National Hurricane Center

Ernesto (AL052024) DATA RELEASED: 8/20/2024 3:00:00 AM UTC

Copy of official data

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