Boulder Hut Adventures
Myself, Jock Richardson and Mark Yancey just spent a week at Boulder Hut Adventures in the southern Purcell mountains northwest of Kimberly, B.C. on a Canadian Avalanche Association Level 1 program. We arrived on Jan 5th prior to a significant wind event on the 4th of January after receiving over 100 cm of snow a week before our arrival.
Over the course of the week we received 70cm of snowfall.
We spent all week digging in the snowpack between 1800-2400meters on most aspects to gain information and data to support our decision making for our course objectives and our management of the hazards. From our information gathering we found a few critical layers in the mid and lower snow pack. One of which was the late Dec 30th surface hoar that was down 60-80 cm from the surface.
Our tests and observations found that this layer is degrading and rounding out; however it is showing hard sudden planar, resistant planar and non results. Although this is an improving trend, it is indicating lingering uncertainty and complexity in the snowpack. We felt that this layer is still highly susceptible to weather stresses like big abrupt snow loading, wind events or sudden increases in temperatures or solar inputs. As such, we treated this layer with plenty of respect.
We also found the late November crust/facet interface down 120-180cm depending on elevation and aspect. This layer exhibited its very serious nature on Jan 10th when we observed 2 large avalanches on east aspects, direct action wind loading from strong south and westerly loading patterns that produced 2 large size 2.5 and size 3.0 avalanches off the east face of Higgins and the bowl between Mt. Higgins and Mt. Crosscut.
Prior to our arrival, there was evidence of avalanches that took out timber to historic levels. Data on the return period of these avalanches was at least 16 years.
The winds that initiated these avalanches took place on Jan 9th. The winds on this day were notably moderate to strong from the south and southwest and redistributed the available storm snow into east and northeast aspects.
Overall, the ski quality was excellent all week and we enjoyed our time at Boulder Hut Adventures in the southeastern Purcells. Our assessment of the snowpack in this area is that it is still highly complex, will require some discipline by both professional and recreationalist's alike. It will require some time before the late Dec surface hoar persistent layers and Nov 30th deep persistent layers become resolved.