Terrain

We skied simple to challenging terrain from 1300m to 2400m in the Spearhead range, Fitzsimmons range and the Duffey Lake area on all aspects. We skied two days in the alpine with limited visibility and two days at treeline and below.

Weather

We were welcomed at the tail end of an intense and warm storm cycle ending with heavy precipitation and freezing levels to 1800m. Monsoon rains below and heavy snowfall above. With the departure of the pineapple express on January 29, freezing levels dropped to 500m before rising to 1200m by the weeks end. Winds were generally moderate to strong from the south west. Through the week roughly 30-50cm of snow fell at higher elevations, a mix of snow, rain, and sorrow below 1400m.

Snowpack

The 170-200cms of previous storm snow from the previous week continued to settle below the new snow with mild temperatures and rising freezing levels. Above this 30-5ocms of new snow was redistributed by strong to extreme SW winds at upper elevations, particularly in the Alpine where the snow was loaded into leeward and cross loaded NW-E aspects.

The 180106 and 180116 Melt Freeze crusts were found to be well preserved and unreactive to testing 150-250 down at treeline elevations in the Whistler backcountry; In the Duffey Lake area these crusts were found to be at a shallower depth ranging from 80-180cm. Below 1500m the rising freezing levels formed a supportive crust that is now 10-20cm below moist snow. Overall snow depths were over 300cms at treeline elevations in the Whistler and Duffey Lake areas.

Avalanche Observations

Throughout the week our primary avalanche concern was a deep persistent slab (January Crusts) with potential to be triggered by cornice fall or a small surface avalanche in motion. A secondary concern was windslab developing in the alpine and open treeline with consistent moderate to strong SW winds. On January 30 we observed numerous natural deep slab avalanches on a north aspect at treeline in the Duffey lake area. These were about 180cm deep and failed on the January 6 melt freeze crust, with one notably stepping down the the late November crust.

Poor visibility limited our observations, but throughout the week others in the region continued to observe sporadic deep slab avalanches on this layer. This instability appears to be more reactive in the Duffey Lake area than in the Whistler backcountry.

Ski Quality

During the week we skied powder snow above 1600m. Windward terrain in the alpine and treeline became increasingly scoured and wind affected, but skied well. Great skiing was found in sheltered terrain. Below 1600m conditions were variable with shallow new snow on a re-frozen surface and off trail travel at low elevations was slow and challenging. On Friday, we observed new snow becoming moist below 1800m on all aspects.