Pioneer Valley residents were gearing up over the weekend for the season’s first significant snowstorm, which was forecasted to sweep the region Sunday evening and cause headaches for the morning commute.

More than 20 schools in New England planned to close today due to snow, according to New England Cable News.

As of 4 p.m. Sunday, the National Weather Service forecasted between 4 and 6 inches of snowfall in the eastern parts of Franklin and Hampshire counties, and 6 to 8 inches of snow in the western parts.

The precipitation was set to start Sunday evening and last until late Monday morning, said meteorologist Glenn Field of the National Weather Service.

He added that the weather service put the western portion of the two counties under a “winter storm warning” Sunday afternoon. That’s an upgrade from a “winter weather advisory,” which the eastern part of the two counties is under.

Around daybreak Monday, Field said, residents can expect either rain or freezing rain, depending on the temperature locally. He said temperatures are expected to be between 30 and 35 degrees throughout the region Monday morning.

“Right around daybreak or a little after, there could actually be a little bit of rain just to add to the misery,” Field said. “It’s not very much, but even a hundredth of an inch of freezing rain could make it very icy.”

The National Weather Service warned that the storm will have a significant impact on Monday morning’s rush hour.

Field said the weather service predicts a strong Arctic cold front that could bring “dangerously cold wind chills” later in the week, he said. He said one wave will move through Thursday and another Friday.

Temperatures in the valley will range at the low end from 0 to 5 degrees below zero, Field said. A wind chill index between 15 and 25 degrees below zero could make outside feel even more biting, he said.

He said area residents can also expect 30-mph wind gusts.

“That’s going to be brutally cold,” Field said.

A blanket of snow will also cover the Great Lakes. The wintry weather mostly moved out of the Plains overnight, leaving parts of Minnesota with up to a foot of snow, and pushed into Wisconsin, Illinois and Indiana.

The Chicago area received 3 to 4 inches of snow as of Sunday morning, and could see another 3 to 5 inches Sunday. The city’s aviation website said more than 1,200 flights had been canceled at O’Hare and 175 at Midway as of late Sunday morning.

Michigan could see the heaviest snowfall, up to 10 inches. It caused problems Sunday when a Delta plane with 70 passengers and crew landed at Detroit Metropolitan Airport but then ended up in snowy grass while it was turning from the runway to a taxiway. No injuries were reported.

To the east, Cleveland could see up to 6 inches, while parts of Vermont could see up to a foot.

The Ohio River valley and Mid-Atlantic will see a mix of snow, freezing rain and rain.

Stephanie Murray and Jack Suntrup, both For The Recorder, and the Associated Press contributed to this report.