Traveled with the A team today - Westminster College Level 1 Avalanche Awareness class. Route was in the Willows and included looking for preserved layer of facets sitting on top of crust. This layer is buried 70 cms (28") down where we were looking today (8500 - 9000' on SW through SE aspects), and this layer has been responsible for several avalanches this past week.
In the photo you can see Samantha talking to the group about the snowpack structure after her team's evaluation, with an arrow pointing to the layer of concern she identified.
We got three loud collapses while traveling in this terrain. And in several pits we dug, we were getting clean Q1 shears in the faceted layer just above the crust. Compression test score ranged from 10 - 25 taps. However, two pits also were unable to isolate a column (CTV). Extended column propagated at 18 taps, but did not pop out with much energy - Q2/RP.
Our group decided we would not travel on any slopes steeper than the low 30 degrees if this structure was present. Our rationale:
- Recent avalanches on this layer
- Three loud collapses
- Stability tests indicating the persistent weak layer remains sensitive.
Great example of evidence-based decision making!
Strong and fun group of Westminster College students today!
