Skied a south-facing line off Ymir Peak and observed no signs of instability but signs of wind effect. The rain crust from earlier in the week is supportive, with about 30 cm of new snow sitting on top. On the way out, we chose to drop a northwest-facing chute into Ymir Bowl (a lee aspect). The first skier entered the gully and cut across it, triggering a wind slab that released the entire gully (size 1.5/2. The skier stopped after sliding only a couple of meters—no injuries. The 30 cm of new snow sheared cleanly on the rain crust.
Definitely a good reminder not to get complacent early in the season. As the snowpack builds, that rain crust could produce bigger avalanches.