Okay, so there is a F6 tornado headed my way and I only have 20 minutes to prepare. What would I do?
I live out in the country, about 20 minutes from anywhere. The last thing I would want is to be on a rural highway and caught by a tornado. I have elderly parents living on the property as well, so I would stay at home and take my chances there and use the time to prepare as best I could. I would gather blankets, pillows, battery-powered lighting, bottled water, power bars or packaged food, a battery-powered weather radio, and a cell phone. Once I had the parents and items tucked-in somewhere, under the stairs, in a hallway or bath, I would keep an eye out as long as possible. If the tornado approached, I'd head for the shelter and start praying, and keep it up until it was over. One way, or another.
Of course, you also have to understand that not only do I live on a rural property that's 20 minutes from the nearest town, but Oklahoma is not heavily populated. I think that on the last census there were about 3 million people in the entire state. As such, when you're out in the country, you rely on yourself for the most part.
If you're interested, you might check out this link. This shows you the destructive capacity of an F5 tornado. http://newsok.com/may3