Add a key to the colors on the map.
Is violet more snow than blue? It would help if somewhere on the edge of the map a legend for the precipitation type/amount was visible. I could not find what all the different colors meant anywhere. By not having that information readily available, a large amount of information provided by the map is uninterpretable.
I concur — this is critical. I've added it to the list of items we're considering for our upgrade.