A strong winter storm accompanied by Arctic cold is poised to bring “significant wintry weather” this weekend to about a dozen states across the middle of the country, from the Central Plains to the Mid-Atlantic, according to the Weather Prediction Center, with forecasters warning that some places may get their heaviest snowfall in a decade or more.

The storm is expected to bring a nasty mix of sleet, snow and freezing rain that is expected to disrupt travel and daily life with road closures, flight delays and power outages beginning Saturday and lasting through Monday.

As the storm moves on, Arctic air is predicted to settle in its wake, as some of the most frigid temperatures of the season are expected to linger for days.

Some state officials were already gearing up for the worst on Friday.

In Missouri, the governor put the National Guard on standby, and Gov. Glenn Youngkin of Virginia declared a state of emergency, days ahead of the storm’s arrival, and urged people to avoid traveling on Sunday.

Cities from Cincinnati to Chicago to St. Louis began the work of pretreating their roads and preparing warming centers.