Snow on After Effects

[Tim Kurkoski]

If you have AE 6.5 Pro, on the install disk there is a set of effects from Cycore that you can install. One of them (CC Snow) produces a fairly decent, if simple, snow effect.

[Rosscoe]

Yo may also be able to achieve snow by using a particle generator like trapcode particular, and then using a noise filter, with this it would be good as you could add turbulence etc if you wanted to

[Andrei Firtich]

Here is a way using photoshop layers
1. Go to photoshop, make a document size 780 width and say 3000 height(# is variable).
2. Fill the layer with black.
3. Apply noise(Filter Noise, Add noise, choose monochromatic, do say 75%, once again number is variable.
4. Duplicate layer couple of times.
5. Bring to AE export as composition.
6. Scale one of the layers say to 800 %
7. apply fast blur,blur to your liking
8. change blending mode to add,
9. make another one 500 % and make another one 250.
10. Keyframe the position of the layers to offset the y coordinate. 11. Apply levels to the layers to take off the mass of the noise. That is move the left side of histagram to choke off some white
12. Apply turbulent Displace. On the front layer you want to leave the settings on factory default and keyframe Offset on the y coordinate, on the other layers take of the size and amount, Experiment, experiment, experiment. This filter is render intensive so changing your resolution to half(control+shift+J) will help.

You can try adding some glow for extra touch. Keep in mind, when you keyframe the position to keep the perspective in mind, move the foreground faster than background to sell the shot.
Hope this gives you some ideas to get started.
Another way to go about it would be making a mask shape and using particle generator to spew it
Hope this has helped 🙂
Andrei