On Thursday, June 4, 2015 at 6:31:20 PM UTC-7, Bill D wrote:
This afternoon about 3PM a very large and powerful dust devil removed a 30' section of roof from Lisa's Family Resturant. Many glider pilots will be familiar with this establishment - it's a very well built building. There also were reports of large trees down in city parks.

The dust devil which did the damage was the first in a line of even larger ones. There were no cumulus overhead one could associate with the mini-twister.

Is there such a thing as a F2 dust devil? Yee-Haaa

Probably, or at least should be. And, probably also F3, F4, and F5. Been in one, and watched one on the ground in the same area. Look back at my article in October 2014 Soaring Magazine on Rogue Air. Nasty stuff.

Bob T.