Professional Observation

Observation Details

Signs of Unstable Snow

4-10” of new snow above 9000’ with totals increasing at higher elevations and closer to the Sierra crest.

I observed two recent Avalanches off the sierra crest.  One in Jaws and one in the upper Hammil bowl. Both looked to be natural events, and both looked to be D1 in size. I could not see the crown of the one in Hammil but the debris was reminiscent of a Loose Dry slough or a small soft slab. The avalanche that ran in Jaws had a sharp crown that looked to be at least a foot or 2 in-depth but again the debris fan was relatively small and reminiscent of a soft slab.

Several pockets of reactive Wind Slab on leeward catchment zones near treeline off the Red cone approach ridge. Slab thickness measured up to 18” but relatively small panels of snow overall. Slab density was 4finger/Fist and I would say these deposits felt sensitive.

Following the shift to North winds last night, upper elevation northerly start zones have largely been stripped back to the old snow surface along the crest in the lakes basin.

As we move into March the sun continues to move higher in the sky and days are getting longer. Despite temperatures remaining below freezing, solar input was quite intense today and we observed some surface moistening on solar aspects NTL and BTL. Some very minor natural rollerball activity was observed initiated by tree bombs along the red cone approach. We also observed some areas of recent melt-freeze crust development in areas that had seen the sun in the morning and were back in the shade by the afternoon.

Snow Stability