I agree with Susan's feeling here. Shots 1, 2 and 4 look underexposed and are greyer than they should be. They are likely underexposed because the camera meter saw so much sky and the snow reflected it. This scene is NOT normal (no even representation of times) and so it needed to be adjusted ....no camera on planet earth can do this as far as I know....the photographer needs to see this and do it.
The solution here would have been to open up (increase exposure) by a good 1.5-2 stops.

Note how shot 3 is fairly well exposed...it has a MUCH more even representation of tones so the camera meter's reading is more accurate.

Hope that helps - Marko