Sand storm effect

I'm trying to get a sand storm overlay effect, kinda in the lines of this:



I was wondering what the best method for achieving this would be.KFC2013-12-24 12:40:58

If I were to make it I would create the animation in Photoshop at game size, than size it down to like 62x62 import it in C2 and scale it up to game size.

I was thinking if using WebGL shader effects, like in the C2 haze effect example, is possible to create a sandstorm effect.