Snow-covered cars in a parking lot greet early morning risers in Madison, Wis. as a severe winter storm moves through the upper Midwest Thursday, Dec. 20, 2012. (AP Photo/Wisconsin State Journal, John Hart)

Early morning motorists travel west along I-70 and into a winter storm near Lawrence, Kan., Thursday, Dec. 20, 2012. Winter weather advisories are in effect for the area. The Midwest's first major snowstorm of the season was sweeping across several states early Thursday, shuttering schools, creating treacherous roadways and threatening to slow down one of the nation's busiest airports ahead of the holiday weekend. (AP Photo/Orlin Wagner)

Early morning motorists travel west along I-70 and into a winter storm near Lawrence, Kan., Thursday, Dec. 20, 2012. Winter weather advisories are in effect for the area. The Midwest's first major snowstorm of the season was sweeping across several states early Thursday, shuttering schools, creating treacherous roadways and threatening to slow down one of the nation's busiest airports ahead of the holiday weekend. (AP Photo/Orlin Wagner)

Mutual of Omaha employees clean their vehicles of snow before leaving on their drive home during the evening commute Wednesday Dec. 20, 2012 in Omaha Neb. A storm that has dumped more than a foot of snow in the Rocky Mountains is heading east and is forecast to bring the first major winter storm of the season to the central plains and Midwest. (AP Photo/The World-Herald, Matt Miller) MAGS OUT; ALL NEBRASKA LOCAL BROADCAST TV OUT

Aziz Erhamah of Omaha Neb., waits for a ride home after his flight was canceled Wednesday night, Dec. 19, 2012 from Eppley Airfield in Omaha, Neb. The first major snowstorm of the season began its slow eastward march across the Midwest early Thursday, creating treacherous driving conditions and threatening to disrupt some of the nation's busiest airports ahead of the holiday weekend. (AP Photo/The Omaha World-Herald, Rebecca S. Gratz) MAGS OUT TV OUT

Don Hunter shovels outside of Gerda's German Restaurant and Bakery in Omaha Neb., Wednesday, Dec. 19, 2012. A storm that has dumped more than a foot of snow in the Rocky Mountains is heading east and is forecast to bring the first major winter storm of the season to the central plains and Midwest. (AP Photo/The World-Herald, Alyssa Schukar) MAGS OUT; ALL NEBRASKA LOCAL BROADCAST TV OUT

Wayne Stuberg cleans the sidewalk from the deep snow in front of his home in Omaha Neb., Thursday Dec. 20, 2012. The first major snowstorm of the season began its slow eastward march across the Midwest early Thursday, creating treacherous driving conditions and threatening to disrupt some of the nation's busiest airports ahead of the holiday weekend. (AP Photo/The Omaha World-Herald, Matt Miller) MAGS OUT TV OUT

Blowing snow reduces vision as motorists wait for a light change in Lawrence, Kan., Thursday, Dec. 20, 2012. The Midwest's first major snowstorm of the season was sweeping across several states early Thursday, shuttering schools, creating treacherous roadways and threatening to slow down one of the nation's busiest airports ahead of the holiday weekend. (AP Photo/Orlin Wagner)

Blowing snow reduces vision as motorists wait for a light change in Lawrence, Kan., Thursday, Dec. 20, 2012. The Midwest's first major snowstorm of the season was sweeping across several states early Thursday, shuttering schools, creating treacherous roadways and threatening to slow down one of the nation's busiest airports ahead of the holiday weekend. (AP Photo/Orlin Wagner)

A local resident clears snow from his driveway after an overnight snowfall left many schools and businesses closed for the day, Thursday, Dec. 20, 2012, in Urbandale, Iowa. (AP Photo/Charlie Neibergall)

A snow plow spreads salt and sand Wednesday Dec. 19, 2012 in Omaha, Neb. A storm that has dumped more than a foot of snow in the Rocky Mountains is heading east and is forecast to bring the first major winter storm of the season to the central plains and Midwest.(AP Photo/The World-Herald, Jimmie Burnett) MAGS OUT; ALL NEBRASKA LOCAL BROADCAST TV OUT

Kiera Kelly curls up to sleep at Eppley Airfield in Omaha Neb., after her flight to Denver was canceled Wednesday Dec. 19, 2012. The first major snowstorm of the season began its slow eastward march across the Midwest early Thursday, creating treacherous driving conditions and threatening to disrupt some of the nation's busiest airports ahead of the holiday weekend. (AP Photo/The Omaha World-Herald, Rebecca S. Gratz) MAGS OUT TV OUT