Tornado activity shifting to the east, study finds
WASHINGTON — Over the past few decades, tornadoes have been shifting — decreasing in Oklahoma, Texas and Kansas and spinning up more in states along the Mississippi River and farther east, a new study shows.
Tornado activity is increasing most in Mississippi, Arkansas, Tennessee, Louisiana, Alabama, Kentucky, Missouri, Illinois, Indiana, Wisconsin, Iowa and parts of Ohio and Michigan, according to a study in the journal Climate and Atmospheric Science. There has been a slight decrease in the Great Plains, with the biggest drop in central and eastern Texas. But even with the decline, Texas still gets the most tornadoes of any state.
The shift could be deadly because the areas with increasing tornado activity are bigger and more populous, said lead author Victor A neighborhood in Vilonia, Ark., was flattened by a tornado in 2014. A new study suggests that tornado activity is shifting east to more vulnerable areas such as Mississippi, Arkansas and Tennessee.
Gensini, a professor of atmospheric sciences at Northern Illinois University.
Even though Texas, Kansas and Oklahoma still get many more tornadoes, the four deadliest states for tornadoes are Alabama, Missouri, Tennessee and Arkansas,
according to the National Oceanic and Atmospheric Administration.
Gensini and tornado scientist Harold Brooks of the National Severe Storms Lab looked at “significant tornado parameters,” a measurement of the key
ingredients of tornado conditions. Scientists consider wind speed and direction at different altitudes, humidity, and the stability of the air to determine the likelihood of a tornado forming.
The study looked at changes since 1979. Everywhere east of the Mississippi, except the west coast of Florida, is seeing some increase in tornado activity. The biggest increase occurred in states bordering the Mississippi River.
Scientists aren’t sure why these changes are happening, but, Gensini said, it
“is super-consistent with climate change.”
As the Great Plains dry out, there’s less moisture to create the type of storms that spawn tornadoes, Gensini said. Tornadoes form along the “dry line,” where more thunderstorms form as dry air from the west meets moist air from the Gulf of Mexico. That dry line is moving east. “This is what you would expect in a climate-change scenario, we just have no way of confirming it at the moment,” Gensini said.
Gensini said that until more detailed studies are available, scientists cannot say for certain that global warming is the cause.