Andesite Peak observations

We went to a known below treeline avalanche path today that has a history of avalanches during persistent slab conditions. This avalanche path has a start zone at just below 7,900', is NNE aspect, and is protected from NE winds. As expected we found the potential future weak layer of well-developed near-surface facets in this avalanche start zone.

We performed two Birkeland, et al. method loaded PSTs. We built 10 cm thick slabs on top of the surface weak layer using disaggregated snow. This snow was allowed to sinter for 1 hr and became a 4F hard slab on top of the F hard faceted weak layer. Both tests scored PST 30/100 SF. We expected to see end propagation results with this test but saw slab fracture instead. Despite these results, it still seems unlikely that this layer would handle over a foot of new snow loading without failure.

In other areas around Andesite Peak, we found variable conditions with firm scoured surfaces on more exposed upper elevation slopes and a mix of firm and soft snow in more tree-covered areas. The southerly aspects on Castle Peak were mostly dirt with a few small patches of snow showing.