Hurricane Ernesto Discussion Number 13
NWS National Hurricane Center Miami FL AL052024
500 PM AST Wed Aug 14 2024
Visible satellite imagery shows that Ernesto's cloud field is
gradually expanding, and there have been hints of an eye potentially
forming in the Central Dense Overcast. The Air Force Reserve
mission from a few hours ago found that the central pressure had
fallen to 989 mb, but there were no indications that the maximum
winds were any higher than 65 kt. The initial intensity is
therefore held at that level, which is also supported by the latest
satellite intensity estimates.
Ernesto is still moving northwestward but continues to turn to the
right, and the initial motion is 325/14 kt. A turn toward the
north-northwest and north is expected tonight and on Thursday as
the hurricane moves through a break in the subtropical ridge, but
the trough causing this break is forecast to leave Ernesto behind
later in the week. The result is that Ernesto is likely to slow
down while it passes very near Bermuda Friday night and Saturday.
Thereafter, a second trough approaching from the west should cause
Ernesto to accelerate toward the northeast, near or just south of
Atlantic Canada. The track models are in very good agreement on
this scenario, but there is a bit of east-to-west spread after 48
hours. The new NHC track forecast has been nudged eastward after
48 hours to be close to the multi-model consensus aids, although at
this time it is too soon to know exactly how close Ernesto's center
will move to Bermuda this weekend.
An environment of warm ocean waters (around 29 degrees Celsius) and
low to moderate shear should allow Ernesto to strengthen gradually
during the next few days. Most of the intensity models indicate
that the hurricane should peak in intensity in about 48 hours. At
that time, the official forecast shows a peak of 100 kt--major
hurricane--which is near the top end of the guidance and close to
the HAFS-B, COAMPS-TC, and HCCA models. A weakening trend should
begin after 48 hours due to moderate shear and a drier, more stable
atmosphere, but the weakening is likely to be gradual. As a result,
the official forecast keeps Ernesto as a hurricane throughout the
5-day forecast period.