Dew point for tornadoes?

Question

Is there a minimum or something

Answer 1

I also live in the Midwest.  You don't really need a specific dewpoint.  Tornadoes happen when you have a clash of air masses with warmer, humid air ahead of colder, drier air & winds in the atmosphere with varying speeds.  Xenia, OH had a tornado in November 2001.  The warmer & more humid the air, the better the chance that a tornado can form given the right circumstances.

Answer 2

Having lived in the mid-west a minimum dew point that was needed was a dew point of 70 degrees and usually when tornadoes did happen usually the dew point was a little higher 72 - 74. In my opinion anything at 70 or above is enough to fuel a tornado.