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Post-Tropical Cyclone Isaias Forecast Discussion

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WTNT44 KNHC 050838

Post-Tropical Cyclone Isaias Discussion Number  33
NWS National Hurricane Center Miami FL       AL092020
500 AM EDT Wed Aug 05 2020

Surface observations indicate that Isaias continues to gradually
weaken over southeastern Quebec.  There have been a couple of
observing sites with marine exposure along the St. Lawrence River 
that have reported winds of around 35 kt within the past few 
hours. Therefore, the initial intensity is set at that value for 
this advisory.  The post-tropical cyclone should continue to 
weaken today, and the system is expected to be absorbed by a larger 
extratropical low over eastern Canada on Thursday. 

The cyclone has begun to decelerate and is now moving 015/24 kt.
The post-tropical cyclone should continue on a general 
north-northeastward motion with an additional decrease in forward
speed over the next 12-24 hours. The updated NHC track forecast is
similar to previous advisory and is near the middle of the tightly 
clustered dynamical model guidance.

This is the last NHC advisory on Isaias.  Additional information
on the post-tropical cyclone can be found in products issued by 
the Canadian Hurricane Center at:


INIT  05/0900Z 47.5N  71.8W   35 KT  40 MPH...POST-TROPICAL
 12H  05/1800Z 50.7N  70.6W   30 KT  35 MPH...POST-TROP/EXTRATROP
 24H  06/0600Z 53.3N  69.0W   25 KT  30 MPH...POST-TROP/EXTRATROP
 36H  06/1800Z...DISSIPATED

Forecaster Brown