Observation: Public

Observation Details

Signs of Unstable Snow

Observations

Traveled up through Mitchel Creek to around 6100' before skiing into Green Apple Creek down to around 5400'.
It was snowing heavily and we found very saturated snow from overnight rain covered by a few inches of snow this morning below ~5500'. Above there, the snow was drier and much more wind affected. We observed rapid wind transport and some shooting cracks and firm, textured snow on small wind features.
I dug a pit on a SE facing slope around 5700' (photos attached). A thick and obvious rain crust is visible around 55cm below the surface (formed 12/20-21). A thin melt-freeze crust is visible just above that (formed 12/24).
Approximate 50cms of snow sits above this crust combo. This snow is moist and relatively uniform. It is well bonded to the rain and melt-freeze crust at this elevation.

I found 2 weak layers in the upper snowpack:
10cms below the surface is a soft wet layer of snow formed during a period of rain and mixed precip the night of 1/3/21. This seemed to be the most active layer both in column tests (CTE 6-8 taps) and in travel tests today. However, it is wet and will likely heal quickly.
Around 30cms below the surface was a midstorm weak layer that is not visible or discernable in a hand hardness profile. This layer produced consistent CTH results (27-30 taps) with Resistant Planar (Q2) failures.
Both of these layers failed to propagate in extended column tests.

I believe the layer around 30 cms is the same layer found on Newton Ridge on the 3rd, though it showed a propensity to propagate there.
https://nwac.us/public-obs/20210103_newton-canyon-pea-gravel-ridge/

The crust combo down ~50cm in this case also produced different results elsewhere in the zone yesterday.
https://nwac.us/public-obs/20210103_pocket-creek-gunsight-ridge-above-jean-lake/