The Pacific Northwest is famous for its microclimates, but I don't think they're supposed to be quite this "micro".
My wife sent me two pictures from our home this morning taken at the same time. The photo on the left is our front yard, while the photo on the right is our backyard.
Yes, we have tall trees in the backyard but it's not enough of a canopy to block out snow, and we've had several other snow events in the past year that have covered the backyard with snow.
So, not sure what the deal is there, whether there is some sort of warm anomaly in the backyard or perhaps I've inadvertently discovered an anti-snow force field. If I figure out how to harness it, it'll be for sale at your local hardware store soon!