Glacier National Park
Laurent Doré-Mathieu , Saturday 10th April, 2021 7:50PM
We intended to ski Cheops North Bowl but after digging a pit and skinning up a part of the ridge to the entrance of the bowl, we were unsure about the conditions and decided to turn back to ski Balu pass instead. When skiing down Balu pass, on the north side, close to Cheops, we triggered 2 size 1 storm slab avalanches.
Snow conditions were: Deep powder, Powder, Wind affected. Weather conditions were: Cloudy, Stormy, Windy. We rode: Alpine slopes, Convex slopes, Mellow slopes. We avoided: Steep slopes. Riding quality was amazing.
Avalache Conditions: 30cm + of new snow, or significant drifitng, or rain in the last 48 hours.
We observed a layer of ~50cm of unsettled storm snow sitting on a thick windcrust. The new snow didn't seem to be wind affected (except on the ridges) but there was clearly snow transport by the wind on top of ongoing snow precipitations. During the compression test, the windcrust failed after around 20 taps (mod-Hard). The propagation test didn't show any sign of fracture propagation.
After bailing out from Cheops North bowl and deciding to ski Balu pass, we split the group in 2 to ski 2 different lines on the northern aspect of Balu Pass bowl. Both lines had convexities near the start zone that we had difficulty to clearly assess because of flat light. One person from the first group triggered a size 1 avalanche but wasn't burried and skied out. Shortly after that, a skier from the 2nd group triggered another size 1 avalanche on another convexity and was partly buried but able to dig himself out and ski out.
Both avalanches occurred on convexities that were close together, on north facing slope.