Heavy snow showers of up to 2 feet are expected in the Colorado Rockies and Intermountain West this week, The National Weather Service said.

Winter is tightening its icy grip across much of the country, with a string of states slapped with weather warnings this week amid fears of treacherous conditions. Reduced visibility and heavy snow—up to 6 feet of snow accumulation in some parts—are forecast just days away from Thanksgiving.

A small storm dropped several inches of snow on Colorado’s mountains Sunday night, though only light flurries reached Denver. According to the National Weather Service, a second storm is on the way. NWS forecasters said a “major winter storm” will hit the mountains again Monday night,