While north of the border, parts of Wisconsin measured their snowfall in feet, Rochelle topped the Illinois list with 8 inches Sunday into Monday. Blowing and drifting snow added to the challenge for commuters, and many students found themselves either enjoying a snow day or a Monday of remote learning.
CONTEXT FOR THE STORM
Walker Ashley is a professor at Northern Illinois University who specializes in meteorology. He said March can actually be a pretty snowy month.
It even produces the heaviest snowstorms in places like Denver and Minneapolis.
"I suspect," he said, "it is probably more driven by the fact that we have more moisture in the atmosphere in March than we do in, say, January."
Ashley says he doesn’t put a lot of stock into long-term seasonal forecasts, so it's hard to say if this storm tells us anything about whether we’ll have more extreme weather this spring.
"It's kind of chaos out there," said Ashley. "I don't think there's an overarching climate connection out there that's going to drive our spring. So, I don't have any more insight than a critter that comes out of the ground in February."
He says it was interesting to see last week’s tornado and hailstorm followed so quickly by snow, but since March is a time of transition, it’s not unheard of.
Overall, northwest Illinois got the most snow in the state. Rockford got around six inches. North of the border, some Wisconsin cities saw record-breaking snowfall.
THE SCIENCE BEHIND THE STORM
Illinois — along with much of the U.S. — is experiencing what’s called a midlevel cyclone. Like a hurricane, these storms happen because the jet stream in our atmosphere is making big swings north and south.
These swings have a lot to do with large temperature and pressure differences in our atmosphere. In the spring, when it’s still cold in the north and warm in the south, it means a lot of unusual weather in the region.
Illinois State Climatologist Trent Ford said those swings explain the multitude of weather advisories across the country.
"When the jet stream is right over Illinois, and when it's particularly wavy, then we have some interesting weather," he said. "We have warmer air colliding with colder air. We can get the situation like what we had last night, where in Champaign, there were tornado warnings, and in DeKalb there were blizzard warnings."
Dynamic weather is pretty typical of the spring season, but Ford said these extremes are like typical spring weather on steroids.
The National Weather Service posted many different weather warnings for Illinois last night.
"Usually it's one or two colors, you know," Ford said. "Because you're dealing with a tornado warning or whatever. And the state was just like Joseph and his Technicolor dream coat yesterday."
Ford said the worst of the storm is moving east, but much of the state can expect some snow in the coming days.
He'll also be closely watching temperatures into next week, which could drop to record lows in the state. The weather could also impact agricultural activity.
Copy Edited by Eryn Lent
