Heavy snow and high winds are causing blizzard conditions in the Upper Midwest. It's the latest stage of a three-day storm that's placed over half the country under winter weather warnings.

More than 200 million people — about 60% of the U.S. population — were under a winter weather advisory or warning on Friday, the National Weather Service said. Nearly 5,000 flights have been canceled.

Nationwide, thousands of flights were canceled or delayed. In some places, temperatures dropped more than 30 degrees in an hour. Wind chills reached well below zero. Inches of snow fell.

Biting wind and heavy snow are expected across 17 states this week, sending temperatures plummeting as low as minus 30 F in some areas. Blizzard conditions could hit the Upper Midwest on Thursday.

Icy winter weather can mean frozen pipes or roof damage. Here are some helpful tips for getting your home through the colder months of the year.

The National Weather Service said it was too early to predict snowfall totals but warned that "blizzard conditions near the coast" could occur depending on the storm's path.

Four governors declared a state of emergency ahead of this weekend's storm, which could drop several inches of snow on areas that aren't accustomed to severe winter weather.

Four governors declared a state of emergency ahead of this weekend's storm, which could drop several inches of snow on areas that aren't accustomed to severe winter weather.

Forecasters predict a quarter-inch of ice which could lead to days without electricity.

Having an emergency kit filled with first aid supplies, water and snacks is an important first step to keeping safe, and sane, if you find yourself stuck on the road. A well-maintained car helps, too.

Texas Gov. Greg Abbott deployed the Texas National Guard to move people without heat and power into shelters.

More than 150 million are under warnings and advisories stretching from the South and Northwest and into the Northeast. The entire state of Texas was under winter advisories on Sunday.

A Fort Worth police spokesperson said between 75 and 100 vehicles appear to have been involved in the Thursday morning crash, which authorities declared a mass casualty event.

Ski areas are seeing record sales of season passes as people look for outdoor exercise this winter. Most are requiring masks, limiting lodge use, and making people put their boots on at their cars.

The National Weather Service canceled its winter weather advisory for all counties, but a wind chill advisory goes into effect from 2 to 11 a.m. Wednesday.