Wisconsin state offices remained open on Monday.
When that jet stream occasionally weakens and buckles, he said, it disrupts weather patterns - bumping warmer air into Alaska and pushing cold winds down into the US Midwest and East Coast, Chenard said. More than 2,000 flights involving U.S. airports are canceled for Tuesday and Wednesday, including more than 1,000 in and out of Chicago airports, according to FlightAware.com. O'Hare was reporting delays averaging 44 minutes, while Midway's delays were lasting less than 15 minutes.
Wind chills in northern IL could fall to negative 55 degrees.
This year's winter has been particularly harsh on the residents of central and eastern United States, who have had to endure an abnormally cold weather pattern since the second week of January. In Michigan, nonessential government offices were closed, including the Capitol.
Alabama Gov. Kay Ivey declared a state of emergency for all of her state's counties Monday, well in advance of the brunt of the storm.
Rare snowfall was also forecast for some southern states.
A winter storm brought several inches of snow to northern IL as the region braces for record-low subzero temperatures. In Chicago, a figure of minus 21 would be the most frigid there since 1994.
Multi-day episode of extreme cold, wind chills expected in North Bay
The wind will die down throughout the evening, so blowing snow won't be much of an issue throughout the overnight and Friday . Wind chills -15 to -25 degrees have prompted a Wind Chill Advisory over this area until 9AM CST this Sunday morning .
The winter storm warning means "severe winter weather conditions will make travel very hazardous or impossible", according to the weather service.
But Monday's snow is just a precursor to what's in store for IL starting Tuesday.
The NWS in Grand Forks, North Dakota reported Tuesday morning that parts of the state were experiencing wind chills as cold as minus 57 degrees. With a projected high of 12 degrees below zero on Wednesday, Chicago is looking at one of the coldest days on record. Chicago looks a few degrees above its record.
Heavy snow and powerful wind created blizzard-like conditions Monday across parts of the Midwest, prompting officials to cancel about 1,000 flights at Chicago's airports and close hundreds of schools.
In Wisconsin, plow drivers were having a hard time keeping up with the snow in Sheboygan. And once the snowstorm is over, forecasters say record cold is expected to settle into the region.
Models indicate rain showers and a mix of rain and snow is possible for our western counties Tuesday morning.
The largest public school districts in Wisconsin and Minnesota were among those closed Monday, including districts in Milwaukee, Minneapolis and St. Paul.
"The term "polar vortex" has become more commonly used in the past couple of years but the phenomenon has been around forever", National Weather Service meteorologist Mark Chenard told Reuters in an interview.