Growing up in the Midwest, I always knew that tornadoes were more of a thing for us than other parts of the U.S. But that never really hit home until I viewed this glowing, clawed map of the U.S. by John Nelson, where each glowing etch represents the path of a tornado tracked in the last 56 years by the National Oceanographic and Atmospheric Administration (NOAA).
“Probably the most challenging aspect of making the map was just paring back on what to show. Early drafts had all sorts of summaries, and data references, and a more complicated map because there is so much great information in the data,” Nelson tells Co.Design. “But when I just drew the data largely as-is on the map, it immediately had a clear message and visual punch.”
For a Midwesterner, that punch is undeniable. The middle of the country has seen Tron’s wrath–how anything has been left standing in this luminescently ravaged zone is beyond me. The East Coast has had their share of tornadoes. And the West? It’s basically one big tornado-free zone.
But there’s more to see here than just where tornadoes happened. Nelson designates each tornado’s Fujita scale ranking–F0 to F5–by its brightness. So the biggest, baddest tornadoes glow the brightest. And what I quickly pieced together was that, from what I could tell, the bigger tornadoes traveled the furthest because the longest lines seemed to be the brightest. Notably, this wasn’t a hypothesis that Nelson had even considered, but checking the data, he realized that his visualization had taught us both something we hadn’t realized before. “Turns out the more voracious the storm the farther it tends to travel,” he wrote. “You sent me back to the data on this one to verify, and sure enough. Here’s a breakdown by F-scale:
F0: 7 Deaths, 267 Injuries, 2 Miles
F1: 111 Deaths, 3,270 Injuries, 6.58 Miles
F2: 363 Deaths, 10,373 Injuries, 11.4 Miles
F3: 958 Deaths, 18,160 Injuries, 17.80 Miles
F4: 1,912 Deaths, 28,427 Injuries, 28.62 Miles
F5: 1,013 Deaths, 11,038 Injuries, 38.87 Miles“
Of course, a bit of further research shows these results may actually be correlative. You see, the Fujita scale doesn’t actually convey tornado size as many of us have come to believe. It’s actually an approximation of tornado severity based upon its damage–from broken branches, to uprooted trees to missing houses–not a measurement of circumference or wind speed. (Or at least, it wasn’t, until in the last few years scientists have agreed on the “enhanced” Fujita scale that accommodates for factors like wind speed.)
With that in mind, of course the tornadoes that traveled the furthest tended to have the highest Fujita scale rankings–a small tornado that hit the ground more often would cause more measurable damage than a large tornado that stayed in the sky. In other words, Nelson’s graphic taught me one last lesson: The biggest tornadoes aren’t the scariest. The longest ones are. (Though certainly, many of the longest tornadoes are the biggest, too.)