( NewsNation) — Tens of millions of Americans were under winter weather alerts Monday morning as they headed home from their holiday trips. Storms have swept coast to coast, bringing everything from blizzard conditions and ice to heavy rain and even tornado threats — creating disruptions for travelers.

Thousands of flight delays are slowing travelers in the U.S. as a dangerous mix of winter weather blankets the Midwest. Slick roads led to multiple crashes in several states. The same system spawned tornadoes in Illinois that scattered debris across neighborhoods.

The strongest wind gusts are expected later Friday morning as a cold front sweeps across the state. Strong winds will continue through Friday evening.