This is truely amazing, thanks for posting this!
The photographer's name is Jim Reed, and according to his site, he specializes in "severe and unusual weather" photography (his work was the basis for some of the effects in "The Day After Tomorrow").
As for this being doctored, no way. Check out the rest of his stuff on
his site , or do a search for "jim reed" on
corbis.com.
He's obviously spent his career in the middle of some cool-a** storms.