Quick report
- Aspect
- Northeast
- Red Flags
- Recent Avalanches, Poor Snowpack Structure
- Elevation
- 2499 m
- Slope Angle
- 38°
- Red Flags Comment
- <p>Noted slides on both East and West facing walls around Red Pine lake. Couldn't determine timing of slides, but all had seen snow fall since pulling out. Of interest, one 200 foot section of slide came down across the common skin track that skirts east of Red Pine Lk: Lookout!</p>
Dug Northerly (NE and NNW) pits at low and high elevations to compare snowpack structure and stability. The take home points:
- Right-side-up slab hardens from fist to pencil over approximately 100cm thickness, and most of unit can be manhandled without breaking: cohesive.
- Facets near ground still weak, but improving. Under lens, they appear to be rounding. In tests they are hard to activate due to depth or to gained strength. Weakest layer was not at the ground but in a 2-3 cm band nearly 40cm up.
- Differences between elevations: Lower elevation a little damper in the facets, a little shallower, rime-crust barely detectable, and surface hoar in some locations.
A note on stability testing: Got negative results in suspect facets using ECT, perhaps due to depth of snowpack. Still wanting to gauge propensity of facets to propagate fracture, we tried a knock-off version of the Propagation Saw Test (a 90 cm Cross-PST) and did find the failure propagated ahead of saw to end of column with less than half of the column cut*. This suggests a lingering deep instability.
* A study by Eric Knoff comparing results of CPST and PST can be found here: http://www.mtavalanche.com/sites/default/files/The%20PST%20with%20a%20tw...
6 second Cross-PST failure.
Hard-to-see slide crossed standard skinner.
Snowpack
Medium density powder on top of thick, hardening slab. Some wind affect even within valley, particularly on and around the lake. No damp or melt-freeze crust seen on our N aspect tour. Some surface hoar low, near streams.