We only get heavy snows when we get what's called an upslope condition, when there's a low either here or to the west of here, and it pulls the winds west from the east and pushes the air into the mountains. When the air is forced up, it gets wrung out and all the moisture comes out. In the winter, it comes out as snow.
With the jet stream above us heading from the west to the east all the time, this is a rare occurance on this side of the mountains. But when it happens, it *really* dumps. Wow.
