Tornado myths busted

Let me begin by saying this: I’m no meteorologist.

Oh, I wanted to be one. Pined for it, actually. At the ripe old age of eight, my parents had already purchased two Weather Channel videos for my weather video library...for my birthday. Yep, I asked for Weather Channel videos for my birthday. It’s a wonder that any woman ever touched me in a romantically pleasing way.

Five years later, it was James Spann—the suspendered one himself—who told me that the two dragons you must slay in order to succeed in weather school were physics and complex mathematics. My dream died that very moment. From that point forward, the closest I could get to the craft was storm-chasing with my friend Dave Neal and sitting in the CBS 42 Weather Center during a handful of broadcasts.

But hey, I hang with meteorologists. Not the armchair weather folk or the thrill-seekin’, tornado-filming yahoos; I mean the real folks who conquered physics and mathematics and get paid to tell you what the weather is going to be like tomorrow and six days after that. I pepper them with questions, get inside their heads and pay attention to stuff they gripe about; the stuff they wished the public knew about. Stuff like tornado myths.

So read this column. Don’t line the cat pan with it. Don’t wash the windows with it. Read it and take it to heart. Slide it up under a couple of fridge magnets and read it some more. Because tornadoes are, regrettably, a part of life in our corner of the world. And you’ll need all the advantages you can get to survive the next major outbreak.

Myth No. 1—You can take shelter from an approaching tornado under a highway overpass.

So you’re driving along the highway, oblivious to the weather happening around you, when suddenly a tornado is bearing down on you and your automobile. A couple of miles ahead, you spot a highway overpass. You begin to draw what appears to be a logical conclusion.

I mean, where would you rather ride out the brunt of Mother Nature’s fury? In a polyurethane box or sheltered under tons of reinforced concrete and steel? You’ll take the steel and concrete any day. Right?

Wrong.

You see, there’s this phenomenon called the wind tunnel effect, which is a modification of the Venturi effect. In essence, it means that air pushed through a confined space increases in speed. If an EF4 or 5 tornado—which can generate wind speeds of around 200 mph—were to take direct aim at the overpass you’re hiding under, the wind tunnel effect could jack the speed up significantly higher.

This myth gained traction back in 1991, when a couple of inexperienced tornado chasers found themselves being chased by a storm on the Kansas Turnpike. With their camera rolling, they filmed themselves and another family taking shel ter under an overpass. The tornado sideswiped their hideaway and everyone emerged unscathed.

Seventeen people attempted the same escape plan during the May 3, 1999, outbreak in Oklahoma. All but one was sucked out from under the highway by the monster storm. Thankfully, there was only one fatality—by dismemberment, you should know. The rest, according to published reports, suffered broken backs, severe lacerations and severed limbs.

Look, if you’re in a car and a tornado approaches, make for a sturdy building to hide in. If you can’t make it to one, abandon your car and lie as flat as you can in a ditch or culvert. It sounds crazy, I know, but it’s your best chance for survival.

Myth No. 2—If a tornado is approaching your home, open your windows.

Here’s another myth that, on the surface, appears to be fairly logical. You and your family are watching long-form severe weather coverage during a tornado outbreak. A warning is issued for your area, and the local meteorologist warns that you are in the path of the storm. You spring up from the easy chair and, instead of making a bee-line for the safe spot, you begin opening up the windows in your house. Why would you do this? Simple. Your parents did it, their parents did it and so forth. Country folks know this stuff, brother. OK?

Here’s the logic. A tornado is an area of extremely low pressure. If it passes over your house (an area of high pressure by comparison), there’s a chance that the difference in pressure could result in explosive decompression, as the two forces attempt to neutralize each other. Opening the windows, in theory, allows the conflicting pressures to equalize themselves, preventing an explosion and saving your house from the resulting damage.

Here’s the reality. Yes, there is a difference in pressure between the inside of your house and the inside of a tornado. And that, taken on its own, that could result in an explosion, which would theoretically cause major damage to your home. But no house is airtight, which it would have to be in order for explosive decompression to take place. The pressure will equalize itself through some weakness in your house’s construction without you wasting time by opening windows. Considering that most tornado injuries are caused by trauma inflicted by flying shrapnel, chances are a chunk of wood or a brick will open up the windows in your home without your help.

The point is, get to your safe room immediately and don’t waste time on old wives’ tales.

Myth No. 3—Tornadoes don’t hit major city centers.

Just because something is rare doesn’t mean it’s impossible. Such is the case with this myth, that somehow major city centers are immune from a direct strike by a large tornado.

How and why do people believe this? Well, in this day and age, I really couldn’t tell you. Tornadoes have hit downtown areas in Nashville (F3, 1998), Salt Lake City (F2, 1999), Atlanta (EF2, 2008) and St Louis (EF4, 2011), and they were all extensively filmed, photographed and documented.

So...there. That’s it. Tornadoes hit downtown areas of large cities. They do, they have, they will again.

Myth No. 4—Geographical features will protect you from a tornado.

Here’s one that’s a little more conceivable and a little less difficult to disprove. The myth is that if you live on a mountain, or in a valley just below a mountain, that you are generally immune from tornado damage.

There’s some sense to be made from this. Most tornadoes that hit the United States are not monster EF3, 4 or 5 storms. They are generally small, weak and short-lived. As a result, they can exhibit erratic tendencies and sometimes, the terrain in their path can disrupt their circulation pattern and lead to dissipation. A mountain may have such an effect on a storm, as would a deep valley. But let’s be honest here. Chances are you’re not going to lose your life in an EF0 or EF1 tornado, unless you’re just in the wrong place at the wrong time. The bigger and more ferocious a storm is, the less likely a hill or a valley is going to have any effect at all on its dynamics.

To be honest, there has not been sufficient study done on the effects of terrain on tornadoes to adequately prove or disprove this myth, but most weather experts agree: If you’re in the path of a storm, just go to your safe spot. Maybe the mountain will protect you, maybe the valley will protect you, and maybe it won’t. You shouldn’t take that chance.

Matt Hooper writes about whatever his fabulous brain can conceive. Please send your comments to hooperemail@gmail.com.