Interesting Patterns found in Tornadoes and Hailstorms

It seams that mid-west Tornado and Hailstorm patterns are linked to the standard work week and the levels of pollution in the air during those times.

http://www.wired.com/wiredscience/2011/12/tornado-weekends/

I read somewhere that it rains more at the end of the week than at the beginning for the same reason.