Creating snow in After Effects has been updated on PVC.
can use dedicated snow filters or particle systems to create snow that
can be either stylized or realistic. There's filters built into After
Effects like CC Snow, CC Particle World, and Particle Playground -- or
you can use 3rd-party filters like Trapcode Particular (which is AE 3D
camera-aware), Boris FX Snow, Cycore FX HD Snowfall, DigiEffects
Delirium Snow, and GenArts Monsters GT.