The weak layer trifecta

10webCBAC Observations

Date of Observation: 12/27/2022
Name: Zach Guy

Zone: Southeast Mountains
Route Description: PM Snodgrass tour, poking into 1st Bowl, 2nd Bowl, and 3rd Bowl

Observed avalanche activity: Yes
Avalanches: Skier triggered several small facet sluffs that entrained weak snow to the ground. These were in start zones that ran earlier this month.
Weather: Light snowfall started around 3:30 pm.
Snowpack: The snow surface was widespread small grained near surface facets on all aspects. Near the trailhead I found surface hoar up to 4-5mm, but I did not see it anywhere else along my tour, including the main start zones near ridgetop. All three of the start zones that I looked at had avalanched previously and held a very shallow snowpack with very weak facets (2mm) that sluffed easily. The snowpack elsewhere is faceted throughout, weak layer size and strength correlated to snow depth, ranging from 1-2mm. Southerlies held one or two collapsible crusts up to a few cm thick with facets above and below. Wind exposed terrain had a mix of wind crusts and thin hard wind slab over these layers.

Photos:

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