Winter storms sweeping across the northern Plains, Upper Midwest and Southwest could bring holiday travel headaches.

A large winter storm was gaining strength in the Southwest and across the Rockies on Saturday after a morning of rain in Arizona and New Mexico that brought heavy snows to the mountains.

A large winter storm is gathering strength across the Southwest and the Rockies. National Weather Service

Snow accumulations of up to 12 to 18 inches are expected in some areas over the weekend with the highest levels of snowfall striking from northern Nebraska to northwest Minnesota.

Ice accumulation in Savage, Minnesota, was already so thick on Saturday morning that one boy was able to ice skate across the sidewalk.

Making matters only worse for travelers, gusty winds will cause thick snow drifts and bring near blizzard conditions to the same areas of the country where snow is forecast from Saturday night into Sunday morning, the National Weather Service reported. That will cause hazardous travel conditions that could affect airports in Minneapolis, Denver and Dallas.

More than 1,425 flights had been delayed and nearly 140 had been cancelled by noon on Saturday.