Trends in tornado occurrence over the last 50 years do not appear to have changed in conjunction with more greenhouse gases in the atmosphere and patterns of rising temperatures, Shepherd said.

Beyond the climate change question, meteorologists don’t know a lot about why some thunderstorms produce tornadoes and not others. According to the National Oceanic and Atmospheric Administration, only about 1% of thunderstorms generate tornadoes. However, tornado prediction is advancing and evolving.

Weather, says Shepherd, is like mood — it changes all the time. The deeper underlying forces we call “climate” are like personality. Greenhouse gases building up in our ocean atmosphere system, from human activity, influence that personality — which is much harder to undo.