I'm sure this has been brought up in the past but... when I was a kid way back in the mid 70's I read a safety pamphlet which told you how to detect a tornado by turning your TV to a vacant channel and turning the brightness all the way down. If a tornado was nearby, it was said, the screen would brighten or white-out. There was also a similar trick with AM radio-- you could set it to the low end of the dial 520-530khz and tell by the nature of the static if a tornado was near-- intermittent static was caused by lightning whereas a tornado caused a continuous and sustained rushing sound. Obviously, these days we have many other resources at our hands, but did anyone ever use this technique in the past ? Scientifically, what is going on here? Does a tornado cause some sort of electromagnetic interference, or emit RF-- hence being able to "tune it in" on a TV/radio? Just curious!