They do that sometimes. I decided to learn the difference because I am scared of tornadoes. I moved here from Maryland and I never saw so many storms! Here you go...so you know I am not so crazy. Okay, I AM crazy... http://www.weather.com/encyclopedia/thunder/index.html Like I said, I am not telling you to prove I am right. I do not need an inflated ego...I do not want one. I just know it is safer to know the difference.