An unusual snow artifact... The photos below were taken from our deck a few days ago. This was a couple of days after the snow you see actually fell, and the day was relatively warm: slightly above freezing. Somehow that made the conditions right for the snow to slide off our roof in those sheets you see, while staying strong enough to stay in one piece up to five feet long. When I examined them closely, I could see that the side toward me (as I took those photos) was a sheet of crystal-clear ice about a quarter inch thick, while the rest was wet snow. For a sense of the scale, those beams you see are 10x12s (with the 12 inch side vertical on the top beam).