This is the upper air sounding plot for Minneapolis, MN, which is the closest one I can find to Eau Claire. By following the yellow air parcel line to the upper atmosphere the parcel becomes unstable at 350mb. the K Index is stable at nine, and the lifted index is also stable, so all in all a bad example to go off of when there are thunderstorms in Eau Claire. Instead I'll so the relation of Lifted Index with Thunder Storms.
According to The Weather Channel above the middle of the country has the greatest chances of T-Storms while below we have Unisys's Lifted Index data. The areas with the lowest Lifted Index have the greater chance of a storm.