Measuring snow accurately is hard. Many times, meteorologists get complaints from people who think the official snow measurement is too low compared to the picture they've sent of a ruler in the snow on their deck. However, backyard decks are notoriously bad places to measure snow. When the ground is warmer than 32 degrees, like it was this past week, melting snow will lower the deck surface temperature enough to accumulate more snow than sticks on the ground, but it's the ground accumulation that counts.
Another problem with decks is their proximity to the roof. Even a gentle wind will blow a lot of snow off a roof and onto the deck, which can give a false impression of how much snow has actually accumulated. Driveways can also harbor a lot of roof-blown snow. Accurate snow measurements need to be made far away from any trees or structures.