I thought tornadoes only last a couple minutes.
Au contraire...they can hang around as long as they want. They can last anywhere from seconds to hours. I think the average is around 5-10 minutes though.
Its a scary thing to watch a tornado coming right at you. I was at work last summer when my boss came and got me. There was a tornado out in the field next to the barns. We were just watching it when it decided to turn and headed right for us
Ran for the only shelter we could find and waited it out. Luckly it was a weak one and didnt cause much damage. But room 5B (the very one I was just in spraying) lost its section of the roof along with a couple others. Very scary to experiance
I've watched several out in the fields before...99% of the tornados that touch down around here stay in the fields
Preferably things stay that way
Luckly you are ok. Tornados are a strange thing, they can litteraly level an entire block of houses but leave one in the middle practicaly untouched. Have a feeling this might be a bad year for severe storms. Last fall was bad and already starting off on the wrong foot this year
I was lucky that time...Had I been there by myself (which was never unusual...didnt even know the boss was there that day) I probably wouldnt have known anything till the roof came off. Between the radio headset blaring music in my ears and the roar of the power sprayer I would have never guessed a storm was overhead :-/
Maybe you can use some Hollywood anti-tornado technique. 
