A winter storm moving in from the Pacific Ocean was expected to bring a foot or more of snow and 75 mph wind gusts to mountainous areas of California on Tuesday, before aiming for the Midwest and laying down a wintry blanket as it goes, the National Weather Service said.
Even coastal Californians would feel the storm's wrath in the form of high winds and heavy rains, forecasters said.
Weather.com meteorologists said the storm originated in the Gulf of Alaska and was taking a southerly course that would hammer California before the system turns inland and strikes as far northeast as Chicago and the Midwest.
Mountainous parts of Los Angeles, San Diego and Ventura counties in California were under winter storm warnings, and snow could present a danger on mountain highways, including Interstate 15, the weather service said.
Those on the Southern California coast were expected to see see wind-whipped waves. High-surf advisories, predicting waves up to 10 feet, have been issued from Ventura County south through Los Angeles, Orange and San Diego counties.
Up to two inches of rain could fall in some areas as the storm moves through, and high winds and snow are likely to also cause problems inland, in heavily populated Riverside and San Bernardino counties, both of which are under winter storm and high-wind warnings.
After the storm moves through California, it will take a sharp turn and hit the Four Corners states Wednesday and Thursday, bringing widespread snowfall across the mountains of Utah, Colorado, New Mexico and parts of Arizona, Weather.com reported.
Weather Channel meteorologist Nick Wiltgen said that as the storm moved eastward, cold air from Canada and moist air from the western Gulf of Mexico would mix to bring snowfalls of up to an inch an hour for several hours, setting the stage for a "major winter storm" over the Plains that could produce double-digit snowfalls along the Interstate 80 corridor. Just to the south, an icy mix could make travel treacherous.
A huge section of the middle of the country is under a winter storm watch, and the Deep South may see severe thunderstorms.
By the time the weather system reaches the Great Lakes, the snowfall was likely to be minor, Wiltgen said.
However some computer models suggested Chicago would get heavy snow late in the week.
The weather service has issued special weather statements and various winter storm advisories for large parts of the western Great Lakes region.
The Northern Plains were expected to remain in the icy grip of arctic winds, with wind chills in many approaching 40 degrees below zero. Up to nine inches of snow was thought possible in places.
Nearly the entire state of Minnesota and large parts of the Dakotas were under a wind-chill advisory.