- Tornado Alley is shifting to neighboring states, including Arkansas, Louisiana, and Mississippi.
- These and nearby states are experiencing an average increase in tornado touchdowns each year.
- Researchers warn that these twisters could become more severe and devastate much of the central US.
More tornadoes strike US soil than anywhere else in the world — particularly in a region called Tornado Alley.
But in recent years, researchers noticed that fewer tornadoes are touching down in Tornado Alley and more are happening in neighboring states to the East and southeast.
Essentially, Tornado Alley is on the move, and it could be devastating for many states of the central US that aren't prepared.
Where is Tornado Alley?
Historically, Tornado Alley has been a part of the Great Plains region, including west Texas, western and central portions of Oklahoma and Kansas, and most of Nebraska.
But emerging research suggests Tornado Alley is creeping into new territories toward a region called Dixie Alley, which includes Arkansas, Louisiana, Mississippi, Alabama, Tennessee, and Kentucky.
Researchers have noted there's also been a shift further north in states like Iowa, Illinois, and Indiana — although the increase in tornado activity there is slightly less dramatic.
A recent study that examined US tornado data from 1954-2018 found that this shift has been happening over the last 30 years or so.
It's worth noting that just because the Great Plains have seen a slight decline in tornado touchdowns, it doesn't necessarily suggest the central US will no longer be a tornado hotspot in the future, Jana Houser, associate professor of meteorology at Ohio State University, told Insider.
Rather, she said the data suggests other regions are just starting to catch up in terms of tornado numbers.
For example, as the graphic below shows, Kansas and Oklahoma still experienced a significantly higher number of tornadoes than elsewhere in the country from 2002-2021, but Mississippi, Alabama, and Louisiana are basically on the same level.
Why the central US is a tornado hotspot
The ideal conditions for tornadoes include warm, moist air nearer to the ground, cooler, dry air up in the atmosphere, and wind shear — abrupt changes in wind speed or direction.
"This makes the atmosphere convectively 'unstable,' meaning storms will likely occur when properly triggered," said Zuohao Cao, a research scientist in the Meteorological Research Division of Environment and Climate Change Canada.
Few places on Earth have all the right conditions for tornadoes, but the central US is one of them.
Warm, moist air from the Gulf of Mexico mixes with cool air from the Rocky Mountains, creating a wind vortex that can eventually lead to supercells — systems of strong, rotating winds that may go on to spawn a tornado.
Why Tornado Alley is shifting East
We know climate change may increase or intensify extreme weather events. But thus far, scientists haven't been able to draw a conclusive link between global warming and Tornado Alley's eastward shift.
Cao said this is because it's normal for tornado activity to vary a great deal over time and space — in some cases, due to naturally occurring variations in climate, not human-caused ones.
Houser agreed there's not nearly enough scientific evidence to prove that climate change is linked to Tornado Alley's shift — but that the possibility can't be entirely ruled out.
Houser said the mega-drought that's been plaguing the South Central Plains for the last 23 years may be to blame.
Storms are far less likely to arise amid the dry conditions in the original Tornado Alley than they are in the moisture-rich areas farther East.
Another reason could be due to a shift in strong winds that blow from the Gulf of Mexico up north to Texas and Oklahoma. This southerly low-level jet stream brings warm moist air into Tornado Alley, providing a lot of vertical wind shear near the ground — a main ingredient for especially violent tornadoes.
"The strong low-level shears provide a favorable environment for supercell development, which often spawns the most destructive tornadoes in the US compared with nonsupercell tornadoes," Cao told Insider.
Over the last several decades, the southerly flow has become stronger in areas of Dixie Alley, and weaker in the traditional Tornado Alley, which may explain the boost in tornado touchdowns in states farther East.
"Although the physical reason for this shift is not clear yet scientifically, it partially explains the eastward shift of the new Tornado Alley," Cao said.
Devastating implications
As Tornado Alley shifts, there's already been widespread evidence of the destruction this change could bring.
The catastrophic tornado Super Outbreak of April 2011, a flare-up of 362 tornadoes that struck the southeastern US over three days, caused roughly 321 deaths and $12 billion in damages.
In 2020, a series of Tennessee tornadoes killed 28, injured hundreds, and resulted in billions of dollars in damages.
In March, a string of violent tornadoes hit Illinois, Indiana, Arkansas, Tennessee, and Delaware. One tornado in Mississippi — which brought 200 mph winds — killed at least 26 people, while also leaving hundreds more homeless and destroying a number of buildings.
Those events followed another series of tornadoes that tore into Alabama and Mississippi in mid-March, which damaged homes and downed power lines.
"As the Tornado Alley moves eastward, expands northeastward and southeastward, and generates new tornado activity centers, people living in these areas will be experiencing more tornadoes — especially violent ones," said Guang J. Zhang, a research meteorologist with the Scripps Institution of Oceanography at UC San Diego.
It's also worth noting that most states in the southeast US have a higher population density than those in the Great Plains, meaning this shift could result in even more devastating property damage and deaths.
Not only that, Houser said there's a higher level of poverty in the southeast, leaving those residents and families more vulnerable when it comes to preparing for and recovering from these disasters.
"Communities need to have disaster plans in place for how they will respond if such an event hits," she told Insider.