Rogers pass and the Rockies
The ACMG TAP program just finished a great week of skiing with the Ski Guide exam from March 15-21 2021
Summary of Trips:
Our team skied days trips in the Rockies on White Pyramid, Observation Sub Peak, Cirque Peak, and Mt. Olive, Mt. Field in Yoho and had five days in the Asulkan / Illecillewaet and Connaught drainages in Rogers Pass.
Numerous wet loose avalanches throughout the week, mostly initiating from Treeline and below Treeline on solar aspects. Areas with suspected windslabs were avoided, but little natural activity was observed. The new snow that arrived mid week seemed to be bonding well to the previous surfaces.
Rockies: highly variable height of snow due to consistently strong winds throughout the season generally from the SW/W scouring ridges and glaciers down to bare rock and ice. On average, there is approximately 200cm of snow at treeline and 300cm on glaciers depending on the exposure to wind. Recently, moderate and strong winds from the west have been transporting approximately 15cm of new snow, creating wind slabs on lee aspects and scouring exposed areas. Melt freeze conditions have been prevalent on solar aspects on sunny days, with freezing level generally ranging from 1400m to 1900m. The snowpack is generally well settled and older weak layers have bonded. Shallow areas are heavily faceted.
Rogers Pass: Melt freeze crusts have formed on all solar aspects well into the alpine and at elevations up to about 1900m elsewhere. This began to get buried with flurries March 19. Approximately 30cm of new snow fell in the alpine during the last couple days which made for great skiing where protected but was heavily wind affected in exposed areas. A well settled snowpack for the most part with new snow trying to bond with previous surfaces. BTL crusts were breaking down by the pm and we were finding moist snow below that.
Our ski week started with warm but stable weather and generally clear skies. This gave way to a more typical spring pattern of intense convective flurries and fluctuating temps. New snowfall amounts differed significantly with elevation ranging from 15-40cm over the week. The wind was consistently from the SW/W and most recently in the 40-80km/h range on the 21st, providing significant snow transport in the alpine and treeline.
Our avalanche concerns throughout the week were
1) Loose wet avalanches on southerly aspects and at lower elevations
2) Windslabs in isolated areas in the alpine, which became more widespread on Saturday with the strong winds and new snow
3) Cornices and overhead hazard especially as the day warmed up
4) Loose dry sloughing on steep northerly aspects in the alpine
Difficult ski conditions at lower elevations due to variable temperature and sun crusts. Cornices were large and looming in all regions travelled. The Rockies were heavily wind affected in most locations above tree line.
Happy spring skiing, and dont forget your sunscreen
The ACMG TAP Ski Guide exam candidates and Instructors