Dreaming of a white Christmas?

The U.S. is poised to experience some of the worst holiday weather in decades this week. Winter storms and very cold temperatures are going to affect almost every state and are already threatening many people’s holiday travel plans, CNN reports. 

The Midwest is expected to have blizzard-like conditions, including up to a foot of snow. Over 90 million people are also under winter weather warnings, stretching across 37 states. 

The storm in the central U.S. is expected to intensify quickly in a process known as bombogenesis, explained AccuWeather. This gives rise to what is called the bomb cyclone, where the pressure drops quickly giving the storm explosive strength. The weather is expected to cause both flight cancellations as well as pile-ups on major highways.

In the eastern U.S., many can expect freezing rain that could cause flash floods as well as become snow in some areas. The South will also be experiencing record-cold temperatures. 

Ahead of the weather, over 800 flights have already been delayed. Experts say to be prepared with backup travel plans. “Reconsider what day you want to go on, maybe reconsider the route if you have a connecting city, and reconsider possibly just changing that ticket to later on in the week,” suggested Kathleen Bangs, spokesperson of the tracking site FlightAware.com. Roads will also likely have low visibility, making driving dangerous. 

In addition, temperatures will be incredibly cold and potentially life-threatening. The weather service in Bismarck warned, “The dangerously cold wind chills could cause frostbite on exposed skin in as little as 5 minutes.”