SnowFlow is a 3D Studio Max script/plugin that creates realistic snow with ease! You just pick an object and SnowFlow does the snow for you! Let the snow fall on your 3D objects and scenes with the click of a button.

Features
    self-explaining user interface with integrated help
    one-click-solution in most standard situations
    multiple snow methods for different needs
    advanced settings to get the best out of SnowFlow
    different reality levels to control object interference
    preset system for a faster workflow
    full control over the calculated mesh
    network rendering with any network rendering solution
    system unit check and conversion to achieve full snow details
    autoTune options for better performance
    caching system to prevent unnecessary recalculations
    "SnowPlug" to stick objects into snow surfaces
    "SnowPrint" to make footprints and things like that

Home page - http://www.scriptspot.com/3ds-max/scripts/snowflow-make-snow-with-the-click-of-a-button