Here's OpenSnow's tally for the Sierra as of yesterday.
Many places are over 200 inches for December alone, though that is the whole season for places under 8,000 feet that melted out in November. The above numbers are nearly all upper mountain.
Mine will be updated Saturday and are generally be mid-mountain if available and exclude October except for Mammoth, which was continuously open in November while Tahoe areas were not open at all.
Overall season-to-date totals are higher in the Sierra than any other ski region. Only in the last day or two have many people been able to ski it due to road and lift closures though. Since the big storm cycles started Dec. 13, Dec. 17-19 was the only window of clear weather and the Tahoe areas were not completely covered by then.
Many of these storms have had difficulty pushing inland or even to the leeward side of some mountains.
Average open for holidays: Jackson 81%, Big Sky 80%. Park City 70%, Breck 70%, Vail 82%
Open this Christmas: Jackson 44%, Big Sky 48%, Park City 28%, Breck 29%, Vail 42%
Open today Dec. 30: Jackson 67% , Big Sky 58%, Park City 43%, Breck 45%, Vail 51%
Nearly everyone in the western US is catching up rapidly from the dry November. But the farther inland/leeward side the ski area, the slower the process seems to be. Snow stability is also an obvious concern as the storms continue. Maybe by early next week the numbers above will be much closer to normal.