That stuff seems to be coming from clouds! Might help to spread a large tarp over your property. I think we still have certain "air rights" for the column of air above our property. You might check local authorities and find the party responsible for the clouds.
Locally, we don't allow stuff like that except for a maximum number of days per year. We also have quantity/depth limits as well as a maximum number of consecutive days. You might also have property owners rules or covenants that further restrict this kind of invasion.
Good luck! And be very careful, I'm still not sure what that stuff is but it can be very slippery on roads and sidewalks!
I suggest staying inside as much as possible, preferably with a cozy fire!