955
WTNT45 KNHC 220233
TCDAT5

Hurricane Erin Discussion Number 43
NWS National Hurricane Center Miami FL AL052025
1100 PM AST Thu Aug 21 2025

Erin has changed little in organization during the past several
hours. An area of convection seen near the center in conventional
satellite imagery is associated with a fragment of an inner eyewall
seen in microwave imagery, and outer convective bands continue in
association with the outer wind maximum seen in scatterometer data.
Satellite intensity estimates are in the 75-85 kt range and have
not changed much since the last advisory, and based on this the
initial intensity remains 85 kt. Erin continues to have a very
large area of tropical-storm force winds, and comparing Erin with
other systems around the same intensity and in similar locations
over the past couple of decades indicates that it is around the
90th percentile in size. The cyclone also continues to produce a
very large area of high seas covering nearly the entire western
Atlantic from the Bahamas to Atlantic Canada.

The hurricane is now moving east-northeastward or 065/19 kt. A
faster motion toward the east-northeast is expected within the
mid-latitude westerlies over the next 2-3 days, taking Erin out to
sea over the north Atlantic. Some decrease in forward speed is
expected by 120 h. The track models are tightly clustered, and the
new forecast track has only minor adjustments from the previous
track.

Erin is moving into an area of increasing shear and toward cooler
sea surface temperatures, and the cyclone is expected to merge with
a front and become extratropical in about 36 h. However, global
models forecast that the cyclone will only gradually weaken as it
moves across the north Atlantic. The new intensity forecast is
similar to the previous forecast and is based mainly on a blend of
the GFS and ECMWF surface winds forecasts.


KEY MESSAGES:

1. Erin will continue to produce life-threatening surf and rip
currents along the beaches of the Bahamas, much of the east coast of
the U.S., Bermuda, and Atlantic Canada during the next several days.
Beachgoers in those areas should follow advice from lifeguards,
local authorities, and beach warning flags.

2. Storm surge flooding should subside on the North Carolina Outer
Banks tonight. While this happens, the storm surge will continue to
be accompanied by large waves, leading to significant beach erosion
and overwash, making some roads impassible.

3. Wind gusts to tropical storm force are likely along portions of
the U.S. Mid-Atlantic and southern New England coasts through early
Friday.

4. Tropical storm conditions are expected on Bermuda through early
Friday. Gusts to gale force are possible along the coast of Nova
Scotia on Friday and the Avalon Peninsula of Newfoundland on
Saturday.


FORECAST POSITIONS AND MAX WINDS

INIT 22/0300Z 37.3N 67.0W 85 KT 100 MPH
12H 22/1200Z 38.8N 63.6W 80 KT 90 MPH
24H 23/0000Z 40.7N 58.2W 80 KT 90 MPH
36H 23/1200Z 43.0N 51.1W 75 KT 85 MPH...POST-TROP/EXTRATROP
48H 24/0000Z 46.1N 42.5W 70 KT 80 MPH...POST-TROP/EXTRATROP
60H 24/1200Z 49.3N 34.7W 65 KT 75 MPH...POST-TROP/EXTRATROP
72H 25/0000Z 52.1N 28.1W 65 KT 75 MPH...POST-TROP/EXTRATROP
96H 26/0000Z 56.6N 21.6W 50 KT 60 MPH...POST-TROP/EXTRATROP
120H 27/0000Z 57.5N 20.0W 45 KT 50 MPH...POST-TROP/EXTRATROP

$$
Forecaster Beven


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