Oh yeah, they are frightening when you're in them. I'm not scared when tornado watches come out, but it's ugly when they hit!

Now this site is really interesting (the Storm Prediction Center in Norman, OK) which is totally up to date on the confirmed F-5 and EF-5 tornadoes in the United States, really something! (Oh, the stats are just from 1950 on...even more before that.)

http://www.spc.noaa.gov/faq/tornado/f5torns.html