Last Friday, a tornado near El Reno, Oklahoma killed scientist Tim Samaras, as well as his son and a colleague. The three were tracking the storm in a vehicle — storm chasing, if you will — as part of their ongoing efforts to deploy probes that could capture high-resolution video from inside a tornado. (Samaras' team was one of many practicing a type of science that can basically be described as Twister in real life.) Chasing storms was an important part of what Samaras did. National Geographic reports that tornadoes only developed in roughly two of every 10 storms Samaras tracked, and the probes were only useful in a fraction of the tornadoes they were deployed in.
Samaras' death is tragic, but he wasn't some untrained yahoo out running around on county roads in a tornado for fun. He was there to do a job; a job that would, eventually, help other people survive. That said, if a situation kills experts, you probably don't want to be that untrained person trying to navigate it on your own.
Which brings us to a key point. After a handful of people who survived the Moore tornado credited their survival to driving away from it, people in Oklahoma City apparently responded to Friday's storms by trying to do the same thing. For some, it worked. But others were killed or injured when traffic on highways in the tornado's path ground to a complete halt, clogged with cars full of people who were (either accidentally or intentionally) trying to flee the storm instead of hide from it.
NPR reports that driving away from the storm is actually a growing trend in Oklahoma. The interesting thing is that, for certain people in certain situations, it may not be the worst decision you can make. Here's what Rick Smith of the National Weather Service told NPR:
... fleeing a massive tornado could be a good strategy — if your escape path was wide open. "To me, if I lived in a rural area in western Oklahoma where the population was 100, it would be a very easy decision. If there's a tornado coming, and I've got just a few minutes, and I know that I can drive five minutes south, and park and wait for it to pass, I would probably do that," he said.
The problem, Smith said later, is that this advice is heavily dependent on a) the size of the tornado, b) whether the person in question has a good storm shelter and (most importantly) c) the local population. If you live in a town of 100, or out in a rural area on a farm, that's one thing. In a city, a suburb, or even a crowded exurb, the result can entirely different, especially if the tornadoes are striking around rush hour, which is when the storms that caused the El Reno tornado, and others, hit the Oklahoma City area. Even non-tornadic effects of the storm can change the calculus — in Oklahoma City on Friday, the storms caused severe flash floods, which are really not good things to run into while in a vehicle.
Basically, the "right" answer can vary. But, if you live in a densely populated area, getting in your car is probably not the right way to respond to a tornado siren.
But what if you just happen to be in the car when disaster strikes? Here's one bit of advice — don't hide under an overpass. Following that myth would actually expose you a wind tunnel effect and make you more likely to be hit with flying debris, which is the stuff that kills most tornado victims. Instead, NOAA recommends going to a place that has a tornado shelter (a rest area, a truck stop, etc.) or lying face down in a ditch or ravine below grade.
Image: Harrisburg, IL tornado - flipped car, a Creative Commons Attribution Non-Commercial No-Derivative-Works (2.0) image from statefarm's photostream