We are contemplating a trip through Tornado Alley in April during our kids' spring break. It would be the first half of April and we'd be traveling from Utah through Colorado, Oklahoma, Kansas, Arkans...
I'm now 80, have lived in tornado country all of my life, and have never seen one. (One has struck as close as 10 miles away, however.) It is my guess that only a small fraction of the inhabitants of "tornado country" have ever seen one.
I agree with BB_TX that local TV provides the best information about storms. If you are traveling, you can get weather information over the internet from a local TV station's website.