Tornado Alley is moving east, new study says. But here's why Kansans might not notice

Apr. 19—A recent study from Northern Illinois University projects that supercells, which are the leading cause of tornadoes, could become less common in the Great Plains and more frequent in eastern regions of the U.S.

But Kansans won't notice much of a difference, according to author and atmospheric scientist Walker Ashley, Ph.D.

"I don't think that the declines are going to be noticeable to the average human walking down the street in Wichita," he said. "These are things that carry out over decades."

According to the National Oceanic and Atmospheric Administration, a supercell is a storm that contains "updrafts that rotate about a vertical axis." These storms, usually thunderstorms, cause damaging wind, hail and tornadoes. According to the NOAA, most large, damaging storms are caused by supercells.

The National Weather Service says supercells are most common in the central part of the U.S.

Ashley said as the 21st century continues, he expects the western part of Kansas will start to see a decline in supercells.

"And the reasoning behind that is because ... we think that the south air in the desert southwest and the Mexican Highlands will become warmer and hotter, and that will move over the top of the relatively warm moist air coming in from the Gulf [of Mexico], and it'll effectively cap ... the thunderstorm development," he said.

"That's not to say that thunderstorms aren't going to occur and supercells [and] tornadoes [won't] occur. It just will produce a more hostile environment overall, in the 21st century for thunderstorm development," he continued.

The study was conducted using a global climate model fed into a weather model. Then, researchers ran the models historically through the end of the 20th century under two different warming regimes for the future, an "intermediate" warming scenario and a "pessimistic" one. Researchers ran the models on a supercomputer funded by the National Science Foundation.

"What we found is a notable increase in supercell production in the Mid-South, the Ozark Plateau, and kind of the lower Ohio Valley, so particularly east of I-35," Ashley said.

The 'expanding bullseye'

One of the reasons why Kansans won't notice the eastward shift in Tornado Alley actually isn't weather-related.

"Tornado Alley" refers to the area of the U.S. where tornadoes most commonly occur. It includes parts of Kansas, Oklahoma, Nebraska and Texas, according to Brittanica.

Ashley said when looking at changes in weather hazards over the years, it's common to try to pin the reasons on a difficult-to-understand topic. Instead, the answer is usually more simple. For Wichita specifically, Ashley said the city is actually more prone to hazards caused by tornadoes due to what he calls the "expanding bullseye."

"The elephant in the room, a lot of times, it's just ... more of us and more of our things spread across the landscape in a very risky area, such as southeast Kansas," he said.

Ashley said the expanding bullseye concept means if a historic storm to hit the area today with the exact same intensity, it would be more hazardous.

"When combined with a hazard landscape that is possibly being reshaped by climate change, the expanding bullseye effect suggests the potential for more and greater disasters in our future," he wrote in a 2015 article, co-authored by Stephen Strader, for Weatherwise.

This means expanding development has made it more possible for tornadoes to cause damage, so it's less likely a possible change in the number of tornadoes will even be noticed.

"If you think of us humans as a bullseye on a dartboard [and] the darts are the tornadoes," Ashley said, "what we've done is we've allowed this bullseye to grow and grow and grow over time, so it's far easier for any one dart to hit the dartboard."

Tornadoes in Kansas

According to a study by Policygenius, Kansas experienced an average of 86 tornadoes per year from 1997 to 2022. Last year the state saw 66, according to the same report.

April through June is considered "tornado season" in Kansas, but severe weather can happen at any time. According to Policygenius, the most common month for tornadoes is May, while the winter seasons see the least.

Averages from 1997 to 2022 ranked Kansas second in number of tornadoes, just behind Texas and right before Oklahoma.

Policygenius, an online insurance marketplace, also ranked Kansas No. 6 among states with the most tornadoes in 2022 using data from the NOAA.

The top 10 states with most tornadoes last year were:

1. Mississippi

2. Texas

3. Alabama

4. Minnesota

5. Florida

6. Kansas

7. Louisiana

8. Arkansas

9. Georgia

10. Iowa

How to prepare for possible tornadoes

Here are some tips to prepare for severe weather and tornadoes, from the U.S. Centers for Disease Control and Prevention:

— Pay attention to local weather by signing up for weather alerts and following media

— Know the warning signs of severe weather, like a dark or green sky, large/dark clouds, large hail and more

— Keep an emergency kit with water, nonperishable food, medication and more

— Keep a list of important information handy, like telephone numbers

— Know where to take shelter. For tornadoes, consider a basement, room without windows or the lowest floor

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