Possible F5
This tornado has been under scrutiny by Environment Canada in recent years, as to whether or not it could be considered for an F5 rating. If done this would make it the earliest such tornado since records have been kept, next to the Elie, Manitoba tornado. The tornado's maximum recorded wind speed was 416 km/h (258 mph). The wind speed for an F5 tornado is 419 km/h (260 mph).
Read more about this topic: Edmonton Tornado