The picture shows it as more solid than it really was. It looked like the sort of cloud burst that you get out of CB's but this appeared to be a heavy snow shower out of stratus. What sort of cloud is it?
My guess would be that it's virga out of a small shower without much vertical extent. If it were rain, you'd hardly notice the precip, but since it's snow, it's much more noticeable, particularly on the photo -- which is really beautiful.