Tornado Alley, the part of the Western and Midwestern United States where tornadoes are most likely to occur, is shifting eastward, and climate change is almost certainly at least partially to blame.
There is basically no part of the United States, or indeed the world (with a few exceptions), that is 100 percent safe from tornadoes. But in the U.S., the overwhelming majority of them have occurred in the so-called “Tornado Alley.” Depending on which scientist you ask (there’s no official definition), Tornado Alley extends roughly from northern Texas, northward into much of western Kansas and eastern Colorado, and into parts of Nebraska and South Dakota.
The reasons for the existence of the so-called “Tornado Alley” have to do with a confluence of climate, geography, and topography. Basically, as warm, moist air extends from the tropics and into the Plains, it’s met by cold, dry air coming from the Arctic, spawning twisters. With wide plains extending hundreds of miles in any direction, and no mountains to disrupt them, the area has, for as long as humans have been recording these things, been bedeviled by them – moreso than other parts of the country, anyway.
That’s all changing, and Tornado Alley is shifting eastward, according to a new study released Wednesday in the academic journal Climate and Atmospheric Science.
— Wes Peery-11Alive (@WesWeather) October 17, 2018
As KCPQ-TV (Seattle) explains, scientists looked over the data from 1979 and beyond, and found that more tornadoes are occurring in states east of the traditional Tornado Alley. Specifically, states that border the Mississippi River, such as Iowa, Missouri, Arkansas, and Tennessee, as well as states even further east such as Indiana, are seeing more tornadoes. Meanwhile, Texas and Oklahoma are seeing fewer tornadoes.
In fact, the four deadliest states for tornadoes are all outside of Tornado Alley, those being Alabama, Missouri, Tennessee, and Arkansas.
Northern Illinois University professor Victor Gensini admits that researchers don’t know why this is happening, but he says climate change almost certainly plays a role.
“We don’t know [why this is happening]. This is super consistent with climate change. This is what you would expect in a climate change scenario, we just have no way of confirming it at the moment.”
The shift is occurring in part because the Great Plains are drying out, leaving less moisture in the atmosphere to produce tornadoes. That’s pushing the “dry line,” as meteorologists call it, to the east.
As Tornado Alley moves eastward, it means that tornadoes will become more deadly. That’s because more eastern states like Missouri and Illinois are much more densely populated than their western counterparts like Oklahoma or Texas.