I think that's how i did it in CS3, ill try that and get back here to see if it works. But for the snow, that might be a bit harder... Any suggestions on the snow?
EDIT: Heres what i did, its the same as CS3. New layer on top of picture, paint it all black. Add monochromatic noise, high intensity. Gaussian blur. Then motion blur. I set that layer property to "screen" and then adjusted the levels to make it look like snow.