Round Mountain snowpack

Sea to Sky

AitorA , Monday 11th January, 2021 7:40PM

We didn't adventure too far or too high on to big Alpine terrain or open slopes but the new storm snow is definetly heavy and reactive at Treeline. The hazard will go up tomorrow with a bigger load and the raising freezing levels. There was also, no signs of wind slabs on Treeline lee slopes, it seems that the surface snow is too heavy for transport at that elevation. The main goal was to investigate what the December 9th Persistent Weak Layer looks like near Squamish. Check the snowpack tab for information about test results and more. The most relevant points about the December 9th Persistent Weak Layer are: - On sheltered, Treeline terrain there is a big load on top of it (+200cm) and this load is generally pretty cohesive. These two combined make it hard for a skier to trigger the PWL. - Due to the mild winter that we are experiencing in the Squamish area, the facets that once and because of a shallow snowpack formed over the crust, seem now to be rounding. This is less likely up in Alpine terrain. - The bad news is that we are on a low probability- high consequence scenario. If you find a place that has less than 1 meter of snow over the crust and you are able to initiate a fracture, the potential for wide propagation and a deep slab is there. Be safe out there and give the snowpack time to heal.

Snow conditions were: Heavy. Weather conditions were: Warm, Foggy, Cloudy. We rode: Mellow slopes, Dense trees. We avoided: Alpine slopes, Steep slopes, Convex slopes, Open trees. Riding quality was ok.

Avalache Conditions: Rapid temperature rise to near zero degrees or wet surface snow. 30cm + of new snow, or significant drifitng, or rain in the last 48 hours.


-Compression Test Results- CTE 2(RP) down 19cm on new snow, density change. X2 CTE 3(RP), 4(RP) down 34cm on new snow, density change. CTM 12 (RP) down 65cm on decomposing precipitation particles. -Deep Tap Results- DTH 30(RP) down 200cm on rounding facets over December 9th crust.

Source: Avalanche Canada MIN