"How to survive a tornado?"
First you have to move out of the state of Alabama.
"Is it better to hide in basement or bathtub?"
Better to hide in the basement because that bathtub is going to chase you around the house.
"Is there any sign of tornado?"
In Alabama, the first sign is usually watching your neighbor circle your house at a high rate of speed.
An F5 tornado can have speeds of from 261MPH to 318MPH (416 to 510km/h).
Kansas - Highest number of F5 tornadoes since 1880
Iowa - Greatest number of F5's per square mile
Alabama - Highest percentage of tornadoes rated as of significant intensity
Kentucky - Highest percentage of all tornadoes ranked as violent (F4 or F5)
What makes Alabama's tornado alley so deadly is that it is both hilly and woody. Meaning that you can't see them coming. Most of the other places don't have both of these things to put up with.
"Anyone have real experience with tornado?"
In 1992 a tornado left a half mile path straight at my house only to turn and miss it by about 50 feet. It did take down about 25 to 30 trees on the edge of my yard, and I now have a half mile view through the woods behind my house.
In 1998 my wife's cousin was killed in this F5 torando. His name is the third one down on the left, on the memorial.
