No, Major Tornadoes Are Not More Frequent

Literally, before the debris stopped falling from the sky in Chicago Sunday evening, we had this on Twitter...

Not only was this in terrible taste, it is factually incorrect. Violent tornadoes are less frequent in a warmer climate. 

There is nothing particularly controversial about this; it follows from classical global warming theory: the Arctic warms more quickly than the tropics so there is less atmospheric energy (on average) available for violent tornadoes.

A note for global warming advocates: regardless of the truth or falsehood of your contentions, stop with the tornado-pertinent tweets while warnings are still in effect.