Ready? Think fast.
A tornado is approaching. You're inside your warm, snuggly house and you only have a few minutes to decide what to do to help prevent horrible destruction and possible bodily injury from the storm. Should you open the windows, in the hopes that the low pressure from the system will fill the house and not cause the windows to blow? Or should you not even give the windows a second of your time, and just hightail it to the safest place in the house?
Before we answer the question, let's talk a little bit about tornadoes. Whirling, stormy twisters create a path of unholy destruction everywhere they go. Dervishes with so much pressure built up that they pop open houses like so many tight seams, and rip roofs off buildings. Do you see what we're getting at here?
Tornadoes aren't going to calm down when they encounter an open window. They're going to blow right through it and never look back. But of course, that's the short answer to the question. Where, exactly, did we get the idea that opening up a house to equalize pressure in a tornado would work? And is there some other strategy that might help?
First off, you weren't just hearing old wives' tales. It really was the standard wisdom for a while that the extreme pressure of a tornado would less affect a house if you opened it up, to allow equalization between outside and in. The thought was that if you left your windows closed, the low pressure of the twister would cause the higher pressure in the house to push out [source: Williams]. The hypothetical result? An exploding house.
Now, when this theory was actually put to the test? Researchers found it didn't hold up. Leaving windows open actually caused the force of the tornado to push up on the roof of the house, while the gusts of the twister lifted the roof. Open windows and doors, in other words, resulted in an airborne roof [source: Williams].
The bottom line? A tornado is much too strong to "equalize" with the pressure of a house, and if it wants to let itself in through open windows or doors — you better believe it has an aggressive way of doing it. Instead of wasting time running to unlatch locks or open shutters, get yourself to a safe place in the house, hunker down and wait it out.