Will it snow, and if so, how much?

When our son was in High School (LM), he took a course in meteorology and, since then, he refuses to blame the meteorologists for any of their missed forecasts.  He motioned with his hands that we have the mountains on one side and the ocean on the other.  But, I protested, the mountains and the ocean have always been there.  And, he explained, the mountains and the ocean interfere with the upper level winds and that interference makes it hard to predict what is going to happen.

And, as if to prove his point, just today I heard a meteorologist state that, when the storm is over, and the snow has stopped, we can go out and measure, and then we will know just how much snow we got.