Last month, I talked a little bit about the August 6th supercell that impacted parts of Southwest Montana including causing a lot of hail damage in the city of Butte (that account can be read here: http://blog.bigskyconvection.com/2009/08/rare-mountain-supercell-batters-butte.html)
I was going back through my memory and trying to remember storms of similar magnitude and only have one memory of a strong storm like that. I'm not sure of the year as I was a child, but I remember a thunderstorm with very strong wind taking out one huge pine tree in front of my great grandmother's house on Aberdeen and half of the other one. I struggle to remember any hail larger than 1" ... not to mention the size of the stones with this storm. (on August 6th)
I wanted to post some more imagery and links from the storm.
Here are a few more links:
Photo Gallery (KXLF)
National Weather Service (Missoula) report.
Montana Standard Article
I'll try to post more information as I learn.
Plains chase forecast update 4, for April 25
7 hours ago