Illinois had 46 February tornadoes between 1995 and 2022. What causes out-of-season storms?

SUGAR GROVE – Two weeks after an EF-1 tornado struck his hometown of Sugar Grove, Northern Illinois University professor Vittorio Gensini said the most populated areas of Illinois were fortunate.

“We got very, very lucky with this event,” Gensini said. “It’s a matter of time until a significant, or even violent, tornado impacts populated areas of Kane County, DuPage County or Cook County. We dodged another bullet.”

At an NIU STEM Cafe event at Fireside Grille, 49 Sugar Lane in Sugar Grove this month, Gensini, an associate professor in NIU’s Department of Earth, Atmosphere and Environment, told dozens of people his kids were huddled under the stairs in his basement when a tornado warning was issued for Sugar Grove on Feb. 27.

The tornado’s path wound up being less than a mile from his home.

“And let me tell you, as a meteorologist, that’s both a blessing and a curse because you’re sitting there looking at the radar like, ‘I think we’re OK, I think we’re OK, it’s two pixels to the south,’” Gensini said. “You knew what was going to happen. Somebody was going to get hit.”

That tornado touched down near Hartner Road before moving through Waubonsee Community College, damaging trees, signs and a large parking lot light pole, according to the National Weather Service.

The tornado created a damage path 8.2 miles long, extending from north of Sugar Grove and ending in Batavia. Multiple evergreen trees were found snapped 5 to 10 feet above ground level at a farm near Lake Run, according to the National Weather Service, which estimated peak wind speeds at 95 miles per hour.

In an email to Shaw Local News Network, Todd Moore, chairman and associate professor of the Department of Geosciences at Fort Hays State University in western Kansas, wrote that the southeastern U.S., particularly areas near the Gulf of Mexico, have more February tornadoes than Illinois. That doesn’t mean they don’t happen, however.

Between 1995 and 2022, Illinois recorded 46 February tornadoes, with an average of two per year, Moore wrote.

Twelve tornadoes were confirmed to have touched town in Illinois during a severe weather event on Feb. 27 according to to the National Weather Service: 11 in the northern Illinois and Chicago area, and one in Davenport and the Quad Cities area. A tornado also was confirmed in Gary, Indiana that night, according to the NWS.

While weather events and the climate system are linked, it’s difficult for researchers to make a decisive statement about the role of climate change in individual “tornadic events,” Moore said.

“At this time, we cannot attribute any single tornadic event to climate change,” Moore wrote. “We are confident that instability and moisture will increase as the lower atmosphere warms and humidifies, and we have documented these increases across large portions of the U.S., including the Midwest, over the past few decades. This translates to an increase in the potential for severe thunderstorms.”

Moore said that although it’s been proven difficult to document trends in the other ingredients needed for a tornado – what’s known as shear and lift – short-term weather forecasting has seen steadfast advances in the past century.

He said the Feb. 27 tornado-producing storms, which also created multiple reports of large hail, were predicted well in advance.

“[The storms were] pretty well forecasted,” Gensini said. “I would say we could see this kind of possibility coming seven, maybe eight days in advance. The atmosphere started to look like it was becoming favorable for severe storms across Illinois.”

Seven-day weather forecasts are as accurate as five-day forecasts were 20 years ago, Gensini said. That doesn’t mean weather forecasting will improve at the same rate indefinitely, however.

Forecasts will only ever be as accurate as the sum of information used, and without knowing every measurable fact about the atmosphere, some mystery will still exist.

Forecasts are bound by the data used to create them, but Gensini believes other technological advances have allowed meteorologists to better warn the public of dangerous weather events.

“I can say that since the National Weather Service started the wireless emergency alerts there has been a significant reduction in the number of tornado fatalities,” Gensini said. “And it’s not a fool-proof system, not everybody has a smartphone, but I’ll tell you what, in terms of disseminating the information it is absolutely kind of a modern day [National Oceanic and Atmospheric Administration] weather radio, and it’s no doubt making a big, big difference in saving people’s lives.”

Artificial intelligence, employing machine learning to identify severe storms, could be used in the near future by meteorologists seeking to issue faster storm warnings, Gensini said. He doesn’t foresee the technology will remove humans for the final decision, however.

The accuracy and timeliness of those decisions are paramount for human safety, particularly in areas where violent storms are known to occur.

Tornado alley, typically described as a region encompassing a large part of the great plains, is not a region defined by the National Oceanic and Atmospheric Administration because various areas of the U.S. experience different tornado threats at different times of the year.

Still, there have been studies indicating the location of tornado-producing storms could move to the east.

Moore said tornadoes have always been common between the Rocky and Appalachian mountains. Research over the past decade has shown that fewer tornadoes are occurring where tornado alley has classically been defined, however.

“Despite these opposing trends, tornado risk remains throughout the region of the [U.S.] bound by the mountains,” Moore wrote. “Recent studies have shown that instability and moisture are increasing in parts of the Midwest and Southeast [U.S.] so there is some evidence that the so-called eastward shift is related to climatic changes. With that said, much more work is needed to better understand whether this shift is long-term or part of shorter-term variability.”