Inspired from an older Maya 2011 tutorial for creating snow on objects in Maya, Ruchit Bhatt shares his Python Script that will allow you to generate snow with some automation over any polygonal surface providing simple controls for mesh settings and some simple clean up.
Custom Maya python script to generate blobby mesh over selected polygon face
Snow Factory will essentially create a blobby mesh surface over any polygonal surface or face, simply select the object that you wish to create snow over, run the Snow Factory script and select a blobby radius and threshold. Initially it looks more viscous than snow and might actually take some tweaking to get it looking realistic, however, it could certainly provide a good start. Check out the Snow Factory script for Maya here.