OK, this post is going to be mainly about last night, but I'll start with the outlook first, as it makes sense to do so.
An Enhanced Risk is currently in effect for IA, WI and MN. This is followed by the standard Slight and Marginal Risks.
Anyway, on to the biggest part of the post. 2 very large, violent and long lived tornadoes occurred last night, in Elk City, OK and Oklahoma, WI. Both of these storms caused heavy damage, injury totals, and 1 death each.
In Elk City, OK, the tornado was multiple vortex in nature, and completely debarked trees within the neighbourhoods hit hardest. This is a sign of EF4 damage, however, buildings appear to have taken high end EF3 to low end EF4 damage in the worst cases.
Now, on to Oklahoma, WI, where a long lived, significant tornado either levelled or (or at least partially) swept away buildings. In this same location, trees were completely denuded, and extensive wind rowing of debris occurred, with ground scouring also occurring.
I'll have to update this post as more information becomes available.