(CNN) A storm system moving east with rain and snow has put more than 35 million people under winter weather alerts from Colorado to West Virginia.
A swath from eastern Colorado to the Ohio Valley was the hardest-hit on Sunday, said CNN meteorologist Robert Shackelford. Colorado, Kansas, Iowa, Missouri, Illinois, Indiana and Ohio saw snow over the weekend and will continue to see between 2 to 4 inches through Tuesday, Shackelford said. Some areas could see up to 6 inches.
Sunday's weather in Kansas caused major traffic disruptions. A five-vehicle crash, including three tractor-trailers, blocked a portion of Interstate 70, according to the Kansas Highway Patrol.
At Arrowhead Stadium, the snow didn't stop the Kansas City Chiefs or their fans from enjoying their 23-3 win over the Denver Broncos. Tweets from the Chiefs showed players throwing snowballs during warmups and making snow angels.
The system will move into Pennsylvania, New York, eastern Massachusetts, Connecticut and Rhode Island through Tuesday, Shackelford said.
Roads in eastern Nebraska and southwestern Iowa were "partially, if not completely" covered with snow, according to the National Weather Service in Omaha.
Sarpy County, near Omaha, saw a total of 21 weather-related crashes Sunday, Lt. Matt Core, Sarpy County Sheriff's Office night watch commander, told CNN Sunday night.
The Lincoln area got between 1-2 inches of snow, according to CNN meteorologist Michael Guy.
Three people died in a weather-related crash near Greenwood, Nebraska Sunday, according to a press release from the Nebraska State Patrol. Greenwood is about 20 miles from Lincoln.
Four vehicles were involved in the crash on Interstate 80 around 11:12 a.m., the release said. Two people were pronounced dead at the scene and a third person died after being taken to a hospital.
Four other people were injured in the crash -- at least one of whom was in critical condition -- and taken to Omaha-area hospitals for treatment, the release said.
Authorities have not released the names of those involved in the crash until they notify the families, the release said.
About 5 million people are under a flood watch in parts of Kentucky and Virginia and West Virginia, Shackelford said.
There is also an enhanced risk -- level 3 of 5 -- for severe thunderstorms in parts of Louisiana, Mississippi and Alabama for Monday afternoon. About 3 million people are in that zone.