We only looked at sunny aspects in middle elevation terrain, but stability and snowpack structure were better than we expected. We did not see any significant buried surface hoar, and the depth hoar layer is less developed and more isolated here than near Galena Summit and the Salmon Headwaters. A couple caveats: 1) the weak layers/snowpack structure - and snowpack test results and potentially stability - vary a lot with small changes in aspect or elevation 2) we did not get on shady/more northerly facing middle elevation terrain where the depth hoar is likely more widespread and well-developed. We didn't see any significant recent wind-loading at middle and lower elevations, but we observed large scoured patches of rock in the alpine; expect to find wind-loaded slopes at upper elevations.
Around 30-40cm (12-16") of new storm snow. Storm snow was well-graded with denser snow at the bottom and low density powder near the surface. Light snowfall (S-1) starting around 4:00 PM.
30-40cm of new snow from 12/11.
Large variations in snowpack structure (previous to recent storm) over small aspect and elevation differences.
On a non-wind loaded S slope near 8650' with HS 75cm from the bottom there was about 15cm of moist and not very well developed DH with a 2cm P MFcr topped off with 1cm of FC forming a weak layer under the various storm slabs that have bonded fairly well to each other. This 11/26 layer of FC produced ECTP17Q2 and PstEnd 25/100.
SE aspect near 8700': HS=85cm, potential problematic layers were interface under recent storm snow + 12/7 interface (FC with some small SH shards) + FC above a crust about 15cm off the ground. ECTN recent interface and 12/7 and 11/26 crust/FC (all Q2 or Q3/dirty shears), multiple PST Arr in both recent interface layer and FC above crust 70cm down (11/26).
Problem | Location | Distribution | Sensitivity | Size | Comments |
---|---|---|---|---|---|
Persistent Slab |
|
Layer Depth/Date: 60cm 11/26 Comments: Problem specific to this observation |
Very little avalanche terrain exists in the area we traveled in today. We avoided avalanche terrain. If we had the option of traveling in avalanche terrain, we would have considered non-wind loaded slopes with no depth hoar present, but we would have had to be disciplined to stick to narrow aspect and elevation bands that had the better snowpack structure.