https://en.wikipedia.org/wiki/Denver_Convergence_Vorticity_Zone

The microclimatology of mountain ranges is so neat. Denver receives warm winds from its southeast, then those get trapped in the foothills of the Rockies between Denver and Boulder/Golden. The mountains ricochet that air back around and it becomes trapped. In effect Denver tends to become a static hurricane where it’s either the eye or the ring. If everyone else in the region gets a big storm it looks like this. If the storms are dodging all of the other cities, they’re funneled into Denver and they get a high chance of tornado activity. Today Denver was the eye of the hurricane.