A blizzard walloped much of Nebraska early Monday, leading to whiteout conditions in rural areas and slick driving in many spots.

Mayor Chris Beutler declared a snow emergency in Lincoln effective 6 p.m. Monday. At that time, parking will be banned on both sides of arterial streets and emergency snow, bus and school routes.

From midnight to 7 a.m., parking will be banned in snow removal districts: downtown and the Haymarket, University Place; Havelock; Bethany; College View; 11th and G; 17th and Washington; and 25th and Sumner.

On Interstate 80, two 14-vehicle pileups started after westbound semitrailers jack-knifed, temporarily closing separate stretches of the interstate, a Nebraska State Patrol spokesman said. The first occurred near Goehner and left four people in area hospitals. The other was near Greenwood.

And in Lincoln, a woman suffered life-threatening injuries in a crash involving a car, a semitrailer and a traffic signal at 84th Street and Havelock Avenue mid-Monday morning.

Crews were still repairing the damage: North 84th Street reopened from Adams Street to Cornhusker Highway around 4 p.m., but Havelock is expected to be closed from 70th Street to 98th until Tuesday.

The storm also knocked out power to thousands of people across the state.

"We want to emphasize how dangerous this storm can be," said Bryan Tuma, assistant director of the Nebraska Emergency Management Agency.

Most school districts in Nebraska canceled classes. Many were already experiencing heavy snowfalls, with others, including Lincoln Public Schools, anticipating worsening conditions throughout the day.

The University of Nebraska-Lincoln and Nebraska Wesleyan University initially summoned students to their campuses, but later announced that classes and most events were canceled beginning at 3 p.m.

People with tickets to performing arts or athletic events at UNL were encouraged to contact the sponsor.

The weather system arrived Sunday morning in western Nebraska, with Harrison in the northern Panhandle reporting 10 inches by 12:30 p.m.

By Monday morning, it had hit central and northeast Nebraska hard, leading to whiteout conditions from Grand Island to Columbus and South Sioux City. The Norfolk airport measured a 60 mph wind gust with visibility of a quarter-mile in the morning. By afternoon, the city had received 14 inches of snow.

Snowfall totals of a 10 inches or more came in from points all across the state:

* Grant, in southwest Nebraska: 13 inches

* St. Paul, in central Nebraska: 12.6 inches

* Concord, in northeast Nebraska: 12.4 inches

Virtually all of the state's highways north and west of Lincoln were reported as completely covered as of about 9:30 a.m.

Several highways in the Broken Bow area were impassible, and the state reported having more than 600 plows in operation.

"We will feel the impact in eastern Nebraska, southeast Nebraska as we progress throughout the day," Tuma said.

The Lincoln area, where the snow arrived around 7:30 a.m., is expected to see 3 to 4 inches by day's end.

Northern parts of Lancaster County, however, could see more significant totals. Head the opposite direction from Lincoln and the ground may not even turn white.

"Today is going to be a day of gradients in the metro areas," the National Weather Service in Omaha said in a Tweet. "Western sides of Douglas and Sarpy counties getting the most snow, east sides see much less. Same thing for Lancaster County, far northern tip gets the snow, southern Lancaster County may not get much at all.

Around noon, traffic trudged along I-80 between Omaha and Lincoln cautiously. Several cars could be seen sitting off to the side of the interstate. Closer to Lincoln, a jackknifed FedEx truck sat off the road as traffic crawled to a stop to navigate around another truck, which had apparently spun around and now sat idle across the highway.

Nebraska State Patrol Superintendent John Bolduc says drivers should prepare to deal with potentially hazardous driving conditions over the next couple days and, if possible, to avoid travel during the storm.

The city of Lincoln had five material-spreading crews at work Monday morning, patrolling for slick spots at major intersections and bridges. And 20 vehicles with plows and material spreaders were deployed at 6 a.m.

Most area colleges and universities, including UNL, Wesleyan and Union in Lincoln, remained open for the morning.

One candidate for NU Board of Regents, Larry Bradley of Omaha, decried the decision to allow classes to continue.

"If any student, faculty, or staff becomes distressed, endangered, or worse because of lack of common sense by university officials, please contact candidates and current Regents," Bradley said in an email to new outlets.

At the Capitol, the Legislature kept at work. Thirty of 49 senators had checked in by 9:10 a.m., with some kept away by the storm.