682
WTNT45 KNHC 200234
TCDAT5

Hurricane Erin Discussion Number  35
NWS National Hurricane Center Miami FL       AL052025
1100 PM EDT Tue Aug 19 2025

Erin has become a little better organized during the past several
hours. Conventional satellite imagery shows persistent strong
convection near and to the north of the center, while microwave
overpasses and reports from an Air Force Reserve Hurricane Hunter
aircraft indicate that the eyewall is trying to re-form.  However,
these changes have not yet resulted in a tighter inner core wind
field, and the maximum 700-mb flight-level winds of 107 kt were
measured about 100 n mi from the center.  Based on this, the
flight-level winds closer to the center, and satellite intensity
estimates, the initial intensity is decreased to a possibly generous
85 kt.

The initial motion is now 340/10.  The hurricane remains situated in
a weakness or break in the subtropical ridge, and it is expected to
turn northward along the western side of the ridge on Wednesday.
After that, Erin should turn northeastward with some acceleration
as it moves into the southern part of the mid-latitude westerlies
over the north Atlantic.  There are no significant changes to the
forecast track through 72 h, and this part of the track lies near
the center of the tightly-packed track guidance.  After 72 h, the
there is more spread, and the consensus models have shifted a
little northward. In response, this portion of the track has been
shifted to the north.

For the next 36 h, Erin will be in an environment of light to
moderate vertical shear and strong upper-level divergence.  Much of
the intensity guidance suggests the hurricane should strengthen
during this time, if the spread-out wind field can become more
concentrated near the re-formed eyewall. On the basis of this
happening, the new intensity forecast calls for slow strengthening
during the first 36 h. However, an alternative scenario is that the
central pressure falls considerably without a lot of increase in
the winds as the hurricane grows larger.  After 36 h, increasing
shear and the start of extratropical transition should cause
weakening, and Erin is now forecast to become an extratropical low
by 96 h.

It should be noted that the 34- and 50-kt wind speed probabilities
beyond 36 hours in the text and graphical products are likely
underestimating the risk of those winds occurring.  This is because
the forecast wind field of Erin is considerably larger than average
compared to the wind field used to derive the wind speed probability
product.

KEY MESSAGES:

1. Erin is expected 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 and tropical storm conditions are expected
in the North Carolina Outer Banks beginning late Wednesday or
Wednesday night, where Tropical Storm and Storm Surge Warnings are
in effect.  The storm surge will be accompanied by large waves,
leading to significant beach erosion and overwash, making some roads
impassible.  Tropical storm conditions are possible along the
southeastern coast of Virginia, where a Tropical Storm Watch is in
effect, on Thursday.

3. Tropical storm conditions are possible in Bermuda on Thursday and
Friday where a Tropical Storm Watch is in effect.

4. Interests along the U.S. Mid-Atlantic and southern New England
coasts should also monitor the progress of Erin as strong winds are
possible Thursday and Friday.


FORECAST POSITIONS AND MAX WINDS

INIT  20/0300Z 27.7N  73.0W   85 KT 100 MPH
 12H  20/1200Z 29.3N  73.5W   90 KT 105 MPH
 24H  21/0000Z 31.6N  73.4W   95 KT 110 MPH
 36H  21/1200Z 33.8N  72.2W  100 KT 115 MPH
 48H  22/0000Z 35.9N  69.8W   95 KT 110 MPH
 60H  22/1200Z 37.7N  66.3W   90 KT 105 MPH
 72H  23/0000Z 39.3N  62.4W   80 KT  90 MPH
 96H  24/0000Z 42.5N  53.0W   60 KT  70 MPH...POST-TROP/EXTRATROP
120H  25/0000Z 44.8N  42.6W   50 KT  60 MPH...POST-TROP/EXTRATROP

$$
Forecaster Beven