Sand storm effect

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

<img src="https://dl.dropboxusercontent.com/u/35440583/c2forums/Sand%20Storm%20Effect/Sand-particles.mov_2.gif" border="0" />

I was wondering what the best method for achieving this would be.

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.