[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT41 KNHC 080252
TCDAT1

Hurricane Earl Discussion Number  21
NWS National Hurricane Center Miami FL       AL062022
1100 PM AST Wed Sep 07 2022

Earl has resumed intensifying this evening.  A NOAA Hurricane Hunter
aircraft reported a maximum flight-level wind of 107 kt (which
reduces to an intensity of about 95 kt), and the central pressure
has fallen to 970 mb.  Both SFMR and dropsonde data support surface
winds of 80 kt.  Onboard radar has also confirmed a rather large eye
of almost 60 miles (90 km) and a fairly symmetric wind field.  The
initial intensity is increased to 85 kt as a blend of all available
aircraft data, and considering the drop in pressure.

Aircraft center fixes confirm that Earl is still moving northward at
about 8 kt.  This motion is expected to gradually turn
north-northeastward and northeastward and accelerate as Earl moves
between a mid-level ridge to the southeast, and a digging
mid-latitude trough to the northwest in the next couple of days.
The trough is forecast to capture Earl, however there is some
uncertainty in the model guidance to the timing of this interaction
resulting in a larger spread in the along-track positions beyond 72
hours.  The official track forecast is very similar to the previous
forecast and close to the model consensus aids.

The apparent decrease in deep-layer vertical wind shear has likely
allowed Earl to strengthen.  Global model guidance suggests the
shear will continue to abate over the next 36 hours and with
atmospheric conditions remaining conducive, further intensification
is expected. The NHC intensity forecast now shows a quicker rate of
strengthening to a peak of 115 kt at 36 hours.  Earl is expected to
undergo extra-tropical transition in a few days when it moves to
higher latitudes and interacts with an upper-level trough.


KEY MESSAGES:

1.  Although Earl's center is forecast to pass southeast of Bermuda,
the wind field is expected to grow, with tropical-storm-force winds
forecast to spread across the island beginning late Thursday and
continuing through Friday morning.  Hurricane-force winds are
possible on Bermuda late Thursday or Thursday night if Earl's track
shifts farther west than is currently forecast.

2.  Swells generated by Earl are expected to reach Bermuda by
tonight and the U.S. East Coast shortly thereafter.  These swells
are likely to cause life-threatening surf and rip current
conditions through the weekend.  Please consult products from your
local weather office.


FORECAST POSITIONS AND MAX WINDS

INIT  08/0300Z 27.2N  65.5W   85 KT 100 MPH
 12H  08/1200Z 28.6N  65.0W   95 KT 110 MPH
 24H  09/0000Z 30.7N  63.7W  105 KT 120 MPH
 36H  09/1200Z 33.3N  61.2W  115 KT 130 MPH
 48H  10/0000Z 36.6N  57.4W  115 KT 130 MPH
 60H  10/1200Z 40.2N  53.0W  110 KT 125 MPH
 72H  11/0000Z 42.9N  49.1W   80 KT  90 MPH...POST-TROP/EXTRATROP
 96H  12/0000Z 45.0N  44.9W   50 KT  60 MPH...POST-TROP/EXTRATROP
120H  13/0000Z 46.4N  39.7W   40 KT  45 MPH...POST-TROP/EXTRATROP

$$
Forecaster Bucci/Pasch
This weather bulletin was brought to you by:
www.nashvilleweather.net