SnowScape

SnowScape is a PhotoShop plug-in for creating piles of snow, dirt, sand, gooey, slimy stuff, blood and similar effects to your (semi-)transparent images.

You can specify where you want the snow to appear, how sticky it should be, allowing you to control whether the slopes should be smooth or jagged, and of course how much will have to be falling down.

You can even change the color and apply noise to create effects nothing like snowfall.