EXPLAINER: Why South gets more killer tornadoes at night

Forget “The Wizard of Oz.” Tornadoes are causing far more deaths and destruction east and south of Kansas these days. And they’re often doing it in the dark of night.

Tuesday night’s deadly tornado that struck the New Orleans area is the ideal example of what experts say is the 21st century problem with twisters: Killer tornadoes have shifted a bit out of the vast emptiness of the Great Plains, more into the Southeast where there are more people to hit, poorer populations and more trees to obscure twisters from view.

And if that's not enough, these Southeast twisters are more likely to strike at night when they are more dangerous.

Here’s a closer look at what's behind the shift:

WHY ARE TORNADOES KILLING MORE PEOPLE OUTSIDE THE GREAT PLAINS?

Since 2000, nearly 89% of the 1,653 Americans killed by tornadoes — not counting this week’s victims — lived east of the Dakotas, Nebraska, Kansas, Oklahoma and Texas, according to an Associated Press analysis of National Oceanic and Atmospheric Administration data.

Last year, 100 people were killed by tornadoes in Kentucky, Alabama, Illinois, Tennessee, North Carolina, Arkansas, Missouri, Louisiana, Mississippi and Pennsylvania. One person was killed in Texas.

It’s not so much a meteorology problem but a people one, tornado experts said.

“It’s a function of the human-built environment,” said Victor Gensini, a professor of meteorology at Northern Illinois University who specializes in severe storms. “The Mid-South does get a lot of tornadoes, but in the Mid-South we have more things to hit. We have more bull’s eyes on the dartboard. We have more cities. We have more weak frame housing stock. Tornadoes happen more often there at night, which is exactly what we saw last night.”

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