There is a new persistent weak layer of concern. The early season facets are still at the ground, but we haven't seen any confirmed activity on them and the most recent storm and water totals were not enough to bring them back to life. The new concern is a near-surface facet layer most pronounced on the southwest through southeast facing aspects. The goal today was to go look at the snowpack near a large remote trigger avalanche that occurred on a south-facing slope in White Pine, triggered from over 150' away.
We found a steep slope around 9400', about 600' below the avalanche, that didn't seem to have very much wind effect. As soon as we stuck our shovel blades in, there were three obvious sun crusts between 45-70cm down. The layer of concern was about 50 cm down where we found a sun crust, with .5-1mm NSF facets on top. In a stability test, we got ECTP11. The near-surface facets are likely the culprit of the remotely triggered avalanche, and the propagation in the snowpit showed that they are unstable.
To compare the spatial variability of the snowpack, we headed directly across to a northwest-facing aspect within the same elevation band. There were no signs of the near-surface facets, and the facets at the ground gave us zero results.
This is a problem that is currently focused on the south end of the compass and located within the upper 2 feet of snowpack. It is a problem easy to spot, and easy to identify once you are looking at a pit wall, but not a problem that you can see from the surface. Put your shovel blade in the snow, look for these near-surface facets, and perform a quick ECT.
Photos below:
Lower Columbine pit profile & Lower Columbine pit wall
Lower Birthday Chutes pit profile & layer of clustered rounded grains
