Professional Observation

Observation Details

Signs of Unstable Snow

Snow Stability

Key Points

We took advantage of the beautiful weather and went for a tour in the Buttermilk area today and decided to climb and skied the Wahoo gully on Mt Locke.

We were able to make it to drive all the way to McGee creek with only a couple of moments on snow that required high clearance. The north-facing slope on the south side of McGee creek contains enough snow that we decided to park at the creek and walk the remainder of the approach. There are a couple of panels of snow on the road beyond the steep north slope but the road is mostly dry to the upper Humphry’s TH.

Coverage is thin but sufficient to travel on skis/boards up and down from here although some strategy was required to find continuous panels of snow at lower elevations.

NE aspects near treeline were holding a largely unsupportive and faceted snowpack. Warm temperatures and full sun today made for some really gloppy conditions along our ascent through this terrain. By the time we descended this afternoon this loose surface snow was moist and punchy and made for some very grabby turns. We were not able to initiate rollerball or pinwheel activity, but it felt like conditions were close. Surface moistening was not a stability concern on these more polar aspects today but the challenging ski conditions added some objective travel concerns.

The Gully itself was highly variable and textured. Old elevated tracks were visible highlighting the damage done by our recent north winds. We found some areas of chalky soft snow, panels of transitional snow, punchy windboard, and some supportable moist windboard that provided some soft predictable turns. I was able to kick loose some diner plates of wind board on our decent but nothing of concerning size. All in all, it was full value adventure skiing.

We did have one moment on our ascent that surprised us. At about 9600’ on a NE aspect, we initiated a large, slope scale collapse. A loud whoomph and notable settlement occurred but we did not initiate an avalanche. Digging in to investigate we found about 38 CM of pencil hard wind board on top of a very thin layer of facets which in turn was resting on a very hard knife+ layer of windboard. This layer was reactive in our stability tests with mixed results. (CT12SP, CT23SP, ECTN23, ECTX)

No other signs of instability were noted on our tour today.