High intensity snowfall on Donner Summit

I started skiing this morning at 0645 under modest snowfall which quickly reached very high intensities for the next several hours.  Between 0800 and 1000 snowfall was peaking at 20-25 cm/hr (8-9"/hr).  During my short tour 55 cm of new snow fell; small loose dry and shallow soft slab storm avalanches were releasing naturally off steep shoulders and unsupported slopes by 0930.  I measured the average density of the new snow at 4.6%: you could challenge the Utah license-plate slogan with those numbers.