The long term trend is also upwards. Note the two peaks in the late 1970s and at present.
Phil Jones tells us that the 1970s snow was due to cold weather caused by a rapid cooling of the oceans. Joe Romm tells us that recent snow is due to hot weather caused by global climate disruption.
So we have to define two different types of snow – cold snow, and hot snow. The peaks in 1978 and 2010 appeared very similar, but the experts tell us that a tiny increase in atmospheric CO2 concentration has changed the fundamental behaviour of physics and chemistry.
CO2 may well be the most powerful substance in the universe.