S2S Ledge Basin
Sea to Sky
asur90 , Monday 24th February, 2020 8:00PM
@Treeline. We found 5-20cm of low density new snow at sheltered areas. Skiing was great with only small loose dry from steep, convex rolls. No shooting cracks or whumps. No slab formations. @Alpine. We found 0-30cm of variable and wind affected new snow. We saw whumps, shooting cracks and a Wind Slab problem. We triggered a SZ 1 Wind Slab that possibly ran on surface hoar and turned around from our objective.
Snow conditions were: Wind affected, Powder. Weather conditions were: Cold, Foggy, Sunny. We rode: Alpine slopes, Dense trees, Convex slopes, Steep slopes, Open trees. We avoided: Sunny slopes. Riding quality was good.
Avalache Conditions: 30cm + of new snow, or significant drifitng, or rain in the last 48 hours. Slab avalanches today or yesterday. Whumpfing or drum-like sounds or shooting cracks.
We had a look at the upper snowpack and found the recent storm snow sitting on a sun crust with Surface Hoar on top of it, which was reactive. Below this, we found more storm snow from over a week ago, which is pretty well bonded together but sitting on the big February rain event which now has facets within the crust. Some notable results from the Compression Tests: Shovel shear test, STM, down 50cm, failed on facets on the February 01 rain crust. CTE 5, SP and CTH22, RP both down 50cm, both with the same results as above. CTE 5, SC, down 25cm, failed on Surface Hoar on the February 19 sun crust.
On our approach to the line we wanted to ski today, we triggered a small windslab (stubborn) that run fairly easy and far. At the bottom of the couloir, we found wind affected snow with the same slab problem and after thinking about the possible outcome of this problem on a exposed line, we pulled the pin and turned around.
Source: Avalanche Canada MIN