Selective snow

I suspect all of us has seen the phenomenon of it raining on one side of a street but not the other.   I am also sure that  at one time or another we have driven along a road with snow on one side and not the other.  Well, two days ago, I woke up and there was no snow in my front yard. There was no snow in my back yard. But my deck was covered in snow … only the deck. It was a couple of hours later before it occurred to me to take a picture.

One of the most visually stunning examples of selective snow that I've seen was taking spring-time hikes in the foothills above the University of Utah campus after a storm had moved across the Great Salt Lake from NW to SE.  The western ~1/4 to 1/3 of the Salt Lake Valley might be completely white from lake effect snow whereas the airport and downtown of Salt Lake City boasted spring colors.  The demarcation line of snow vs no snow seemed very sharp from that vantage point.