Mammoth has had very little snow all through December and there’s no sign of a change on the horizon alas.
That said, if correct, forecasters do say there may be 20cm of fresh snow at the start of 2018 but it would take some major change in conditions to get near to the historic volumes of snow that fell in January 2017 leaving snow nearly 10 metres deep.
https://www.facebook.com/MammothMountain/videos/10154427751207395/
Currently its 50-150cm deep.
Despite the lack of fresh snow there’s 120 of the centre’s 150 runs open which is more terrain than any other area in the US, they say.