Tornado alley faces more tragedy this season

Tornado alley, that swath of the central United States from Texas to the Dakotas and east to Alabama and Tennessee, is bracing for a rough time this season. Here is what happened when one tornado hit a housing tract in Arkansas:

At least 35 people have died in the past two days as more than 100 tornadoes ripped through Oklahoma, Arkansas, Mississippi and Tennessee. The unfortunate thing is the situation is likely to get worse.

Vox.com, the exceptionally informative website run by Ezra Klein (formerly of The Washington Post's Wonkblog column and a frequent MSNBC commentator) has done some of the best work on helping laypeople understand what is going on. Browse through Vox.com for superb analyses on this year's tornado outbreak (as well as the Affordable Care Act, newsmakers, social science and everything else imaginable). Here is what I gleaned about tornadoes from Vox.com:

The number of tornado deaths per capita has declined in the past century, thanks to better radar and better forecasting from the National Oceanic and Atmospheric Administration. People now have up to 14 minutes of warning to seek shelter. The technology is improving further.

But there are drawbacks. An economist who studies tornado response at Austin College in Texas looked at how people evaluate risk. Giving people a longer warning in advance of a tornado actually may be counterproductive. People may tend to try to leave the area by car, which is the worst thing to do, given a tornado's erratic path. Most of the deaths in the 2013 El Reno tornado came when people tried to flee by car.

Sheltering underground in homes or schools isn't always practical. Soil composition and ground water may limit underground construction. Building stronger conventional structures may help withstand moderate tornadoes but retrofitting existing structures usually is too expensive. Even a dome-shaped building, which deflects winds, cannot withstand an E5 tornado, the strongest.

(And forget about trailer parks. They seem to be tornado magnets.)

It's conceivable that next year's tornado season might be even worse than this year's. That's because of El Nino. The complex weather phenomenon occurs irregularly in the eastern tropical Pacific Ocean and produces widespread weather events across the globe. Add global warming, and 2014 or 2015 could be the hottest year on record. Although the question is debated, some evidence  suggests that El Nino is associated with increased tornado activity in the United States.