The National Weather Service is warning that “a significant, very early-season winter storm will enter the Northern Rockies Saturday. A host of potentially dangerous impacts will result from this type of early winter storm.”

Historic snow and a heat wave? That’s what a downright loopy jet stream pattern is bringing to large parts of the United States.

Parts of the Northern Rockies are bracing for what the National Weather Service in Missoula, MT is describing as an “historic winter storm