036
WTNT45 KNHC 210246
TCDAT5

Hurricane Erin Discussion Number  39
NWS National Hurricane Center Miami FL       AL052025
1100 PM EDT Wed Aug 20 2025

Satellite imagery and reports from an Air Force Reserve Hurricane
Hunter aircraft indicate little change in Erin during the past
several hours. The aircraft reported a central pressure near 942
mb, and the wind data showed two concentric wind maxima - a weaker
one about 15 n mi from the center and a stronger one 60-70 n mi
from the center. The maximum 700-mb flight-level winds in the outer
wind band are near 105 kt. Based on the lack of change since
earlier, the initial intensity remains 95 kt, which is near the
average of the various subjective and objective satellite intensity
estimates.

The initial motion is now 010/14 kt. The steering scenario and
track forecast reasoning are again unchanged from the previous
advisory. Erin should move around the western and northwestern
periphery of the subtropical ridge during the next 12-24 h, passing
between Bermuda and the U.S. east coast.  After that, the system
should accelerate northeastward and east-northeastward while
embedded within the mid-latitude westerlies over the north
Atlantic. The track guidance has changed little, and the new track
forecast is an update of the previous forecast.

A little strengthening could occur during the next 12 h or so,
although the concentric wind maxima structure argues against
significant strengthening. After 12 h, Erin should encounter
increasing westerly shear and move over colder sea surface
temperatures, which should result in steady weakening. The system
is also expected to merge with a frontal system to become an
extratropical low, and while this is currently forecast to occur
by 72 h it could happen earlier.  Erin should continue to weaken
after extratropical transition as it moves east-northeastward
across the north Atlantic.

Erin is an unusually large hurricane.  For hurricanes north of 30N
latitude, its tropical-storm-force wind radii are in the 75th
percentile of the Atlantic basin record.

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 through Thursday.  The storm surge
will be accompanied by large waves, leading to significant beach
erosion and overwash, making some roads impassible.

3. Tropical storm conditions are expected on Thursday along the
Virginia coast. Wind gusts to tropical storm force are likely along
portions of the remainder of the U.S. Mid-Atlantic and southern New
England coasts Thursday through early Friday.

4. Tropical storm conditions are possible on Bermuda on Thursday and
Friday.  Gusts to gale force are possible along the coast of Nova
Scotia on Friday and Newfoundland on Saturday.


FORECAST POSITIONS AND MAX WINDS

INIT  21/0300Z 32.8N  73.1W   95 KT 110 MPH
 12H  21/1200Z 34.8N  71.7W   95 KT 110 MPH
 24H  22/0000Z 36.8N  69.0W   90 KT 105 MPH
 36H  22/1200Z 38.7N  65.2W   85 KT 100 MPH
 48H  23/0000Z 40.4N  60.5W   75 KT  85 MPH
 60H  23/1200Z 42.2N  54.3W   65 KT  75 MPH
 72H  24/0000Z 44.5N  46.8W   50 KT  60 MPH...POST-TROP/EXTRATROP
 96H  25/0000Z 50.0N  31.1W   45 KT  50 MPH...POST-TROP/EXTRATROP
120H  26/0000Z 54.3N  21.8W   40 KT  45 MPH...POST-TROP/EXTRATROP

$$
Forecaster Beven