Vail & Summit County
SnowpackJason Konigsberg · Feb 4, 2023 · Vail & Summit County
Weather
Clear, cool, and windy.
Snowpack
The surface of the snowpack is faceted. This has been well documented across many places in the state over the last few days. In this area near surface facets are dominant with surface hoar less prevalent.---Winds were effectively cross-loading north-facing slopes and top-loading east-facing slopes. The wind loading wasn't particularly intense but it was effective contributing to hard-drifted snow in areas. I did not notice signs that the drifted snow was unstable such as shooting cracks.---The snowpack was supportable to skis from the trailhead at about 10k feet.---I dug on a west-facing (290 deg) near-treeline slope. This area would be representative of the Sky Chute start zones. I found a snowpack that was 117 cm deep. Boot penetration was 60 cm as the slab was quite supportable. The weak layer of concern is the November facets at 22 to 32 cm from the ground. I got a score of ECTX in an extended column test but 28/100 END in a propagation saw test. This shows that the weak layer is hard to affect but propagation propensity has not diminished significantly. In the PST, the block easily slid off the block when the cut length reached 28 cm. The slope angle of the test slope was 30 degrees. Below the weak layer of concern is rounding depth hoar. The depth hoar is now one-finger hard and makes for a good sturdy bed surface for the collapsing facets on top. I also performed a non-standard cross-PST and got similar results as the standard PST.---The snowpack in this area is setup well for a large avalanche cycle if we ever get a moist, multi-day storm. ---Although I did not get propagating results in the upper snowpack, I think smaller avalanches could fail at the top of the faceted slab (47 cm from the surface) with lighter loads.