An armada of snow plows and salt spreaders are deployed on highways across the nation's heartland, working to stay ahead of a powerful winter storm that already is blamed for one road death.

Winter storm warnings have been issued from Colorado through Illinois, with as much as a foot of snow expected in several areas.

National Weather Service meteorologist Kelly Sugden says the storm is moving a bit slower early Thursday morning than had been previously forecast but that it was gaining strength and producing a mixture of snowfall, lightning and sleet showers.