U.S. Tornadoes Shifting Southeast, Could Be Due to Climate Change

A new study shows that tornadoes in the U.S. have been moving southeast over the last few decades.

Researchers from the Purdue University have found that natural disasters are shifting their path across the U.S., from Tornado Alley to Alabama, Georgia, Tennessee, Mississippi and Louisiana, and that the shift is caused by climate change.

"This completely redefines annual tornado activity in the United States," Ernest Agee, a professor in Purdue University's Department of Earth, Atmospheric and Planetary Sciences and lead author of the study, said in a news release.

In a recent study published in the Journal of Applied Meteorology and Climatology, the researchers analyzed data from the past 60 years to look at the changes in annual tornado activity. The 60 years were divided into two groups: years 1954 to 1983, which was a period of cooler temperatures and years 1983 to 2013, which had increasingly warmer temperatures.

Researchers found that there was a decrease in both yearly counts and tornado days in the "Tornado Alley," which encompasses Oklahoma, Kansas, Nebraska and northern Texas. However, the numbers were sustained in the southeast, with a notable increase in "Dixie Alley" region, which includes Alabama, Georgia, Mississippi, Louisiana and Tennessee - which had the greatest increase in tornado days for both period groups.

"As compared to the Great Plains, the southeastern United States experiences more unexpected tornadoes from small storms, tornadoes at night and tornadoes outside of the traditional spring tornado season," Agee said in a statement.

The shift in tornado activity was observed to have taken place during the period of regional temperature spike caused by climate change. But the scientists said that more research is needed to determine if climate change had influenced the results.

"The geographical shift in tornado activity has been established through powerful statistical methods and is shown to occur during two successive 30-year periods moving from a colder weather pattern to warmer conditions," Agee said.

"More research is needed to search for changing climate trends responsible for tornado formation and this geographical shift, but climate change is a distinct possibility."