The usual suspects have tried to tie the recent onslaught of tornadoes to global warming. It is bad science for the reasons explained below. The Weather Science Let's begin with some basic meteorology: strong (F-2 and -3) and violent (F-4 and -5) tornadoes are caused by the contrast  in temperatures between the poles and the tropics. Bad tornadoes need an active jet stream to ventilate the top of severe thunderstorms. You can see the correlation pertaining to Saturday's tornadoes below. The strong jet stream is in the same general area as the tornadoes that killed 22 people. Tornadoes from 1pm Saturday to 7am Sunday Jet stream winds (250mb chart) up to 150 mph (scale is in knots) in the general  vicinity of Saturday's tornadoes The global warming hypothesis -- which has proven to be correct -- is that the poles would warm much more quickly than the tropics. That means there is, on average, less  temperature contrast between air masses and a less powerful jet stream. Thus,...