This is an interesting idea, but there is one big problem. Normal precipitation is done client sided; if you wanted the snow bricks to match up with where snow lands, then that isn't possible using normal precipitation settings. However, it could be done by having the server emulate normal precipitation with small snow projectiles that rain down from above, and cause the snow when they land on bricks or ground. And all the stuff that you could do with the snow is completely possible too.