The ACMG Training and Assessment Program spent the past week (December 8-15) at Rogers Pass and Snowfall Lodge. Below is a summary of our observations.
Weather: The week began with unsettled weather that brought up to 20cms of new snow and light to moderate southerly winds at Rogers pass December 9-10. High pressure weather set in with mainly clear skies, light winds, and seasonal temperatures December 11-13. A cold front brought 15cm of new snow on December 14 with moderate winds transporting snow at ridgetop. Unsettled weather with light flurries on December 15.
Snowpack: 15cm of recent storm snow and some wind effect in exposed alpine. This overlies the December 14th surface hoar to size 5mm in isolated areas below tree line. The December 5th crust is down 30-50cm and is supportive below 2000m where it bridges deeper instabilities in the snowpack. The December 1st surface hoar is down 60-100cm and is producing hard sudden planar results. The bottom of the snowpack is faceted, especially in shallower areas. Average snow depth is 150cm at tree line.
Avalanche activity: Evidence of a widespread natural cycle from December 5/6 storm was observed. No significant avalanche activity observed during the exam other than small size 1 wind slab and loose dry in extreme terrain.
Terrain used: Reasonable ski quality ends around 1800m. We had high confidence in our avalanche hazard assessment below 2000m due to the bridging effect of the December 5th crust over deeper instabilities (e.g., December 1st surface hoar). Between 2000m and 2200m, a cautious approach to terrain was used due to the December 1st persistent weak layer. In the alpine, caution was given to terrain with a shallow facetted snowpack. In addition to managing avalanche problems, caution was also given to early season hazards, especially on glaciers. An average snow depth of 150cm was found on the glaciers above Snowfall Lodge.
Other hazards included open creeks, rocks, and heinous alder. Small cornices are beginning to form.
Stay safe and have fun!
Rich Marshall, Conrad Janzen, Todd Anthony-Malone, the Hurtin’ Albertans, the French Connection, and Team International.
