I have heard grating noises for the last 20 minutes intermittently so finally got out of the van to have a look at what it was. It is not snow that is falling but a very fine ice. The wind is strong enough to be blowing this sideways almost horizontally. This is caking to the side of the van until about quarter of an inch has formed then it slides off. The side of the van looks really strange kind of like a leopard pattern of ice and clean spots.