I was setting up at the Badwater Basin area in Death Valley NP hoping to get a good sunset shot. As I was setting up I noticed some clouds which looked like there could be an evening storm coming across the basin. As I started shooting I noticed that the clouds were heading towards me. As I picked up my gear and started walking towards the car. I didn't want to be caught out in the storm a long way from the car. As I got to the walkway I surprised to find what I thought was a storm was nothing more than a big fog bank moving through the valley.