AURORA | Multiple spinouts on slick and snow-packed roads have created numerous traffic snarls as numerous school and other closures materialized with the winter storm Tuesday morning. All Aurora schools, APS and Cherry Creek Schools, are closed Tuesday.

As of 2 p.m., almost all roads and highways were open, but several major thoroughfares closed intermittently as spun-out and stuck cars clogged roads. Even police cars began suck in roads. Tow services and even city plow crews were overwhelmed with calls for service across Aurora.

At about 9 a.m., police re-opened northbound I-225 from Colfax over the flyover to westbound I-70 after it was closed for about two hours. I-225 off-ramp to East Alameda Avenue was closed for more than an hour this morning.

Police are systematically chaining police cars for this afternoon and tonight. Dispatchers continue to take numerous calls of stuck cars on the side or blocking roads.

Denver International Airport says about 300 flights have been canceled after 7 inches of snow fell, and other flights have been delayed an average of more than three hours.

About 600 miles of Interstate highways across Colorado were snowpacked and icy, and chains or snow tires were required for many mountain roads.

Much of the state was under a winter storm warning, with 12 to 20 inches of snow forecast in some areas and wind gusts expected to reach up to 45 mph, making travel hazardous.

All public schools and evening programs were cancelled for the day.

The National Weather Service is calling for an additional 2-4 inches today. Already, residents in southeast Aurora are reporting more than 12 inches of accumulation, and drifts approaching 3 feet. The storm is expected to move out this evening, and forecasts are for clouds without snow for tomorrow.