A dirty thunderstorm (also, Volcanic lightning) is a weather phenomenon that occurs when lightning is produced in a volcanic plume. A study in the journal Science indicated that electrical charges are generated when rock fragments, ash, and ice particles in a volcanic plume collide and produce static charges, just as ice particles collide in regular thunderstorms.
Lightning struck the Willis Tower (formerly the Sears Tower) in downtown Chicago during a thunderstorm last night. I’m a little concerned about how the photographer got this shot flying during an electrical storm. We’ve all seen the end of Almost Famous, right?
photo via Gawker