The ACMG Training and Assessment Program just finished the second of two Apprentice Ski Guide Touring courses.
From Jan. 28 to Feb. 1 groups skied in the Whistler Blackcomb backcountry and on the Duffey Lake Road.
It was a week of variable weather. The overlying theme being strong to extreme southerly winds and an atmospheric river hitting us midway through with freezing levels going to 2000m and approximately 100mm of precip. The week ended with a clearing and cooling trend.
Conditions and Snowpack Summary:
A warm system brought over 100 mm precipitation over a 48-hour period around January 31, with snowline reaching 2000 m. This was followed by a cooling trend with freezing levels dropping rapidly to valley bottom, tightening the previously moist upper snowpack and creating a rain crust below 2000 m. Strong to extreme winds were associated with this weather system, redistributing the HST in the alpine and treeline. We would expect to find deep wind-loaded deposits on lee slopes in the alpine and lots of new cornice growth. The mid-pack contains various melt-freeze crusts and a generally well consolidated snowpack. The November 23 melt-freeze crust and facet combo persists throughout the region near the bottom of the snowpack. Sheltered alpine features will provide the best ski quality, be prepared for very difficult conditions at lower elevations.
The recent storm produced a widespread natural avalanche cycle. The majority of avalanches were within the new snow and natural cornice failure. However, there were some avalanches failing as deep as the Nov 23rd MFcr/Fc combo.
In the Whistler area we started the week with a conservative approach, avoiding shallow areas and skiing supported terrain up to 30º. As the week progressed we stepped out into 40º terrain that had previous skier traffic, but continued this conservative mindset of avoiding serious avalanche terrain. In the Duffy, on Jan. 29 and 30 (before the storm) we skied in the following areas: Rohr Lake, Lazy Boy Basin, Heartstrings and the Armchair Glacier. Ski quality was good, despite widespread wind effect in the alpine. We avoided thin snowpack areas.
All the best!