A winter storm moving across the country is already proving deadly, and threatens to cause problems if you're hitting the road or taking to the sky this weekend as holiday travel gets underway.

Airlines canceled hundreds of flights and thousands of others were delayed, Friday as winter weather moved into some busy airports, like Chicago.

Overnight Thursday, in Oklahoma temperatures dropped and light rain unexpectedly turned into a dangerous icy mess.

Oklahoma City officials report at least 100 crashes and three deaths because of the icy conditions.

Meanwhile, parts of Oregon are still digging out from snow and ice.

People abandoned their cars around the city of Portland.

"My wheels just kept spinning and I couldn't move forward anymore," said driver Nick Woo.

Ian Tarleton was stuck in his car as well.

"It was mayhem up here," he said. "I mean we couldn't see what was happening until we got up here."

As that weather system moves east, flights are already being preemptively canceled. Most of those cancelations taking place in Chicago.