LONGMONT, Colo. — A powerful storm dumped up to 24 inches of snow in the Colorado mountains Tuesday before barreling onto the plains, prompting airlines to cancel about 500 flights at the Denver airport and leaving hundreds of miles of highways slippery with snow and ice.

The snow tapered off Tuesday afternoon as the storm moved northeast, leaving behind drifts up to four feet high.

“It’s going to be western Nebraska’s turn next,” National Weather Service meteorologist Todd Dankers said. “It’s going to end up eventually in Minnesota.”

It was the first big storm of the season for most of Colorado and Utah. Schools closed in at least four states. Much of the West Coast was dry with below-average temperatures.