How do you create a snow spray effect?

[mimi]

I took photos of my daughter skiing, but even though she's coming down the slope quite fast, it appears as though she is almost standing still and posing. If I can add some snow spray behind her, it ought to give the effect of motion. However, I can't figure out how to do it. I'm relatively new at Photoshop, and I have the CS program. Anyone have any suggestions for me? Thanks in advance!!

[Doug Nelson]

Try adding a layer filled with 50% gray, then use the noise filter (very coarse, monochrome). Then do a levels adjustment pulling both the black and the white sliders in. Then do a motion blur and set blending mode to Lighten.

[Doug Nelson]

I skipped a step. In between adding the noise and adjusting levels, use the Blur More filter. I've found it also works best if the black levels slider is dragged much further than the white slider is.

[mimi]

Thank you very much! I'm off to give it a whirl!