John Metcalfe is CityLab’s Bay Area bureau chief, based in Oakland. His coverage focuses on climate change and the science of cities.
Six decades of twister tracks shows that some places get hit again and again.
North America has entered the beginning of peak tornado season, and the weather certainly reflects that. Today a major spring storm is barreling over the nation's center, and forecasters are warning to watch out for possible damaging winds, large hail, and tornadoes.
So perhaps now's the time to ask the age-old question: If you're terrified of twisters, where's the absolute worst place in the U.S. to live?
There are a couple of answers. In the U.S., areas of intense tornadic activity tend to shift northward as the seasons change. Folks in the Gulf states might expect to see the most twisters during the spring; in the southern plains it's May to early June; in the upper Midwest it's June or July. So the true tornado-phobe will relocate frequently as the weeks tick by, perhaps dodging back and forth in a murky network of underground bunkers.
You can see the risk of tornadoes move up through the country as the year matures in this animation from the Storm Prediction Center. Regions painted in the darkest red have the highest chance of tornadoes – a 1.4 percent probability that one will touch down within 25 miles:
But to make a broad assessment of the most tornado-plagued areas of the U.S., examine the above map of twister tracks from 1950 to 2011 (extra-large version here). The wind-ravaged cartography, made by data-visualization company IDV Solutions with NOAA records, reveals that the country's mid-and-eastern sections are particularly rife with screaming funnels of destruction.
As it's now spring, here is IDV's historical breakdown for the months of March, April, and May. Stronger tornadoes are shown as brighter lines:
Some notable targets hiding under this neon scrabble include Oklahoma City, which has been nailed by twisters at least 140 times since the 1890s. The general O.K. City area has been hammered 26 times by two or more tornadoes on the same day, according to records, including last year's terrible May 31 when five funnels tore through town. There are also several Southern cities in the "Dixie Alley" that've proven vulnerable – such as Huntsville, Alabama, the 2011 setting for one of the worst tornado outbreaks in history. Florida sees its share of twisters as well due to continuous thunderstorm activity, though these spinners are generally weak.
If you have a few minutes to kill, IDV has put together this animation of twister activity over the past six decades. Wait for April 2011 to see a true explosion of major tornadoes: