[The Great Eagle Eye]

Well, if you're unsure, get a plastic bag, like a Ziploc or something, put it around the back of the camera, letting the lens poke out the front. The bag is water-proof, so it'll keep snow out of the primary components and body, just make sure not to let the lens out too far, or it can get water in the glass, and it takes a while to dry/re-focus if that happens.