A winter storm in the mountains outside of Salt Lake City, Utah, caused dangerous road conditions and prompted avalanche warnings on Monday, December 30.According to the Utah Department of Transportation, traction devices were required for vehicles traveling in both the Big and Little Cottonwood Canyons. Officials urged drivers to be cautious of wet and slushy conditions as well as patches of ice on roads.An avalanche warning was in effect through Tuesday morning as the National Weather Service (NWS) warned that heavy snow and strong wind were “creating widespread areas of unstable snow.”“Both human-triggered and natural avalanches are likely,” the NWS said, and advised people to avoid “slopes steeper than 30 degrees.” Credit: UDOT Cottonwood Canyons via Storyful