Trippy.
Where I live, we get something that looks almost like that as a natural phenomenon every summer. Right at the mountain ridge along the Pacific coast, just south of San Francisco, you have many days (if not weeks on end sometime) where there's this massive wall of fog that suspends itself in air along the mountain tops ... a lot like the sand clouds in these photos. Everytime I see it, I still can't get over it. I wish I had photos, because it's pretty amazing.
But sand? With the fog wall, it's just cold and damp. I can only imagine being put through a power sander!