system
Given the following post, respond as if you're commenting on Reddit:
human
Meteorologists: Why or how is "tornado alley" shifting east?

I'm sorry about the flair I was hoping for a meteorology tag.
gpt
It's not confirmed that tornado alley is actually shifting east (tornadoes just aren't common or predictable enough for us to have that kind of data certainty), though recent trends do suggest this is occurring. 

Experts don't have consensus on why yet (they haven't even confirmed it's an actual phenomenon), but a strong hypothesis is that climate change is altering the locations which are most conducive to tornadoes. Tornado formation requires a lot of weather and geography elements to line up, and even a slight change in average temperatures or wind speeds of various regions (these averages make up the climate of a region) could have significant impacts on the chances of the specific weather requirements for a tornado all being met at once in that region.