Hurricane Erin Forecast Discussion Number 18

By | August 15, 2025

Issued at 500 PM AST Fri Aug 15 2025

000
WTNT45 KNHC 152043
TCDAT5
 
Hurricane Erin Discussion Number  18
NWS National Hurricane Center Miami FL       AL052025
500 PM AST Fri Aug 15 2025

Erin continues to slowly become better organized, with convective 
banding increasing near the center and a couple of attempts to form 
an eye.  Earlier Air Force Reserve Hurricane Hunter data did not 
show any increase in winds after the previous advisory, although 
the central pressure fell to near 993 mb.  Satellite intensity 
estimates are in the 60-75 kt range and are gradually increasing. 
The initial intensity is held at 65 kt pending the arrival of the 
next NOAA and Air Force aircraft this evening.
 
The initial motion is 290 to 295 degrees at 15 kt. The subtropical 
ridge to the north will continue to steer Erin west-northwestward 
through the weekend, although the motion during the next 36 h or so 
may be closer to 285 degrees.  After that time, encroaching 
mid-latitude westerly flow is forecast to cause a weakness to 
develop in the ridge, and this will cause Erin to gradually turn 
northward with a decrease in forward speed. The guidance remains in 
fairly good agreement through about 72 hours. After that time, 
there are still differences in both the forward speed and 
cross-track spread with regards the turn toward the north. The 
regional hurricane models again lie along the western edge of the 
guidance envelope, while the GFS remains on the eastern edge.  
Overall, though, there again has been little change in the guidance 
envelope and the new forecast track has only minor adjustments from 
the previous track.  

Erin is forecast to be in an environment of light to occasionally 
moderate northwesterly vertical shear and over sea surface 
temperatures that warm to 29-30C along the forecast track. However, 
there is also a large area of mid-level dry and African dust to the 
north of the hurricane, and the satellite appearance suggests Erin 
is ingesting tongues of dry air.  Although the environment may not 
be ideal, the regional hurricane models are in excellent agreement 
that Erin will reach a peak intensity at or above 120 kt during the 
next 2-4 days.  Based on this, the new intensity forecast now calls 
for a peak intensity of 125 kt in 72 h, and it is possible Erin 
could get stronger than this. As the hurricane gets stronger, there 
is a high chance that eyewall replacement cycles will cause 
fluctuations in intensity that are not included in the current 
forecast. It is also expected that Erin will become very large and 
powerful hurricane by the end of the forecast period in the 
southwestern Atlantic, and the current forecast wind radii at 96-120 
h may not be large enough.


KEY MESSAGES:
 
1. Heavy rainfall tonight through Sunday across the northern Leeward
Islands, the Virgin Islands, and Puerto Rico may lead to isolated
and locally considerable flash and urban flooding, along with
landslides or mudslides.
 
2. Tropical storm conditions are possible for portions of the
northern Leeward Islands, where Tropical Storm Watches are in
effect, beginning on Saturday as the core of Erin passes north of
those islands.  Gusts to tropical storm force are possible in
rainbands over portions of the Virgin Islands and Puerto Rico later
in the weekend.
 
3. While the threat of direct impacts in the Bahamas and along the
east coast of the United States appears to be gradually decreasing,
there will still be a significant risk of dangerous surf and rip
currents along western Atlantic beaches next week.
 
4.  Interests in Bermuda should continue to monitor the progress of
Erin since there is still a risk of strong winds, heavy rainfall,
and high surf by the middle part of next week.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  15/2100Z 18.9N  57.6W   65 KT  75 MPH
 12H  16/0600Z 19.6N  59.9W   75 KT  85 MPH
 24H  16/1800Z 20.4N  62.7W   90 KT 105 MPH
 36H  17/0600Z 21.2N  65.1W  105 KT 120 MPH
 48H  17/1800Z 22.3N  67.1W  115 KT 130 MPH
 60H  18/0600Z 23.4N  68.5W  120 KT 140 MPH
 72H  18/1800Z 24.8N  69.5W  125 KT 145 MPH
 96H  19/1800Z 27.9N  70.6W  120 KT 140 MPH
120H  20/1800Z 32.2N  69.7W  115 KT 130 MPH
 
$$
Forecaster Beven

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