A dangerous winter storm was pummeling large swaths of the US Rockies and western Plains on Sunday morning, forcing the cancellation of hundreds of flights in Denver and shutting down major highways.
Two to 3 feet (0.6 to 0.9 meter) of snow could fall across parts of the region, the National Weather Service said. Blizzard warnings due to high winds were in effect for eastern Wyoming, western Nebraska and southwestern South Dakota.
More than 30,000 customers were without power in Colorado, according to an outage tracker maintained by utility Xcel Energy. Interstate 25 was shut down in both north and south directions from northern Colorado into Wyoming, while Interstate 80 was also closed both eastbound and westbound throughout most of Wyoming.
"STAY HOME. YOU WILL BE STRANDED!" warned the National Weather Service's office in Cheyenne, Wyoming, on Twitter, where more than a foot of snow had fallen since Saturday.
More than 800 flights were canceled at Denver International Airport on Sunday after hundreds of cancellations on Saturday. The airport had seen nearly a foot as of 6:30 a.m. (1230 GMT) on Sunday, with a total accumulation of between 15.5 inches and 27 inches expected, airport officials said.
Colorado Governor Jared Polis activated the National Guard ahead of the storm to assist with any search-and-rescue incidents.