Log Cabin Obs

Rapidly settling storm snow and recent winds made for challenging/variable riding conditions. 10cm of new snow fell at Fraser in the last 24 hrs and the temps warmed up from -26 to 0C at the highway. Unfortunately the new snow was accompanied by moderate to strong southerly winds forming fresh, hard windslabs in the Alpine. The new new snow sits over a variety of weak old surfaces: about 20 cm of facets in sheltered terrain and a thin rimed crust on windward aspects. We didn't see any new avalanche activity in White Pass (to be honest we couldn't see much) but our we spent the day avoiding wind loaded pockets. Another complicating factor was the still shallow snow pack means that the winter snow has not smoothed out the ground roughness in more complex alpine terrain resulting in lots of spatial variability and lots of thinner weak snowpack areas to navigate around. Below tree line the snowpack is mainly faceted.

Our objective for the day was to get a bit more information on the status of the two crusts buried in the snowpack. The bad news is that they are still very much there (we found them down 40-60cm on N aspects up to at least 1400m) and they were reactive in snow pack tests. The good news is that the recent cold temperatures have faceted the upper snow pack, and I think avalanches on this layer are unlikely at the moment, until the overlying snow becomes more cohesive. That said, I expect the forecast warm temperatures will promote settlement in the upper snowpack and these layers could wake up, especially if the region receives a significant load in the snowfall forecast for Thursday. We performed a variety of tests on the deeper and more developed of these two crust/facet layers at tree line. Our propagation saw test results in particular ( https://www.alaskasnow.org/…/uplo…/2011/01/Prop-Saw-Test.pdf) reinforced my opinion that it would be wise to keep this layer on our radar for the time being. I've included a snow-profile for the snowgeeks!