Minnesota in 'Tornado Alley'?

This year, Minnesota had more tornadoes than any other state. If you aren't familiar with normal tornado distribution patterns, that fact is pretty surprising. It's also more than just a weird, one-time anomaly. Experts say this years' numbers seem to be part of a pattern of tornado activity becoming more common in more northerly places. Perennial champion Texas isn't throwing in the towel—it's been the tornado capital for 7 of the last 10 years—but Minnesota seems to be becoming a part of the "Tornado Alley" states, a big change from past precedent.