Quick report
Slab avalanches remain a possibility where a stronger slab rests above weak old snow near the ground. This combination was found in isolated locations along and near exposed ridgelines at middle elevation. Slab avalanches are unlikely where the snowpack is weak from top to bottom. In these areas, dry loose facet-lanches were a consideration in steep terrain.
I did not observe any cracking or collapsing. I traveled in an untracked area and in a good amount of terrain where previous wind affect built a meatier slab over weak snow near the ground.Weather
- Cloud Cover
- few
- Wind Loading
- previous
- Recent Snowfall
- 0
- Snow Avail For Transport
- small smounts
Wispy mid-level cirrus made for some diffuse sunshine. Overall, it was sunny and calm. Some light S wind blew at the ridge top.
Snowpack
Leaving the truck, the snowpack was shallow and weak. I noticed older, crusty snow welded to the ground beginning around 7,600' on a N aspect. As I gained elevation, a layer of depth hoar grew in thickness above the basal crust, reaching up to 20 cm thick. The depth hoar was buried under mostly weak faceted snow.
Ocassionally I'd notice a 4F interval in the "slab" above the weak layer, but the only areas with a consistent slab over weak layer structure were those in previously wind-loaded areas. I dug in two of these locations: on an ESE aspect at 8,800' and a NE aspect at 9,200'. The slab in both locations was 40 cm thick and graded from F to 4F+ at the base. Multiple ECTs in both locations returned ECTNs with moderate and hard force breaking the width of the shovel. I moved the shovel over to do a non-standard test on the shorter column and received the same results in all cases. A CPST on the NE aspect returned CPST 30/100 (SF)
Wrapping to a steep, sheltered, shaded WNW @ 8,900' I found a heavily faceted 50 cm snowpack that lacked any cohesion aside from a friable MFcr down 20 and the basal crust welded to the ground.
The snowpack on steep S-facing slopes around 9,200' was around 20 cm thick. Snow depths on lower angle slopes and/or slopes other than due south thickened to include multiple crusts interspersed with facets.
Surfaces: I found surface hoar in all areas with an open sky view, including exposed ridges right to the top of my high point. All snow surfaces, including old wind slabs, have been faceted.