I'm not sure exactly what sport this is (I can find no evidence of a Shirtless Snow-Diving Jackass League), but it was under the category of sports on YouTube. Maybe there's a winter roof-diving subdivision of gymnastics. The flip is textbook, though I'm not sure he really stuck the landing.
It's like the guy who swam the Amazon, I guess. Just because I don't understand it, doesn't mean it isn't worthwhile.
no shirt [YouTube]