in an ancient dungeon or crypt there could be DUST everywhere!!! a few alterations to the snow system would allow for a nice placement of dust upon items!
alternatively a dungeon could possibly gain an intelligent mist effect upon the floor from a snow system
in a deadric realm there are ash storms...
and im sure sheogorath could make it snow something freaky... any deadra could have some kind of snow in their realm
could the dynamic snow system be used for rain? replacing textures that the rain lands on?
(anything concrete or stone will become shiny, dirt will become mud, skin and leaves would get droplets on, wood and fur would become damp)
anything with a large enough angle would have rain (or mud) pour down it...