Observation: Public
Observation Details
Name:
Robin PenderyObservation Date:
February 28, 2021Submitted:
February 28, 2021Zone or Region:
West SouthActivity:
Skiing/SnowboardingLocation:
Crystal - Bullion Basin and Cement BasinObserved Avalanches
Did you observe any avalanches?
YesAvalanche Type:
Hard SlabSize:
Size 2: Could bury, injure, or kill a personElevation:
6400Aspect:
SWComments:
E side of Cement Basin. Crown appeared to be 200 ft wide, and up to 5 ft deep. The trigger point looked to be a shallower rocky area. The debris ran down 400 ft and contained very small trees and branches.Photo:
Signs of Unstable Snow
Observations
Due to high levels of uncertainty with regards to the recent reemergence of the mid January weak layer in the West South zone, we kept our terrain choices mellow today.
At ridgelines, we found a combination of wind scoured terrain, and 4F wind stiffened surfaces. Active wind transport was occurring throughout the day.
Below ridgelines, we found very good ski conditions and stable storm snow on all elevations down to 6,200. Below 6,200, solar aspects held moist surface snow or a zipper crust from yesterday. We observed some roller balls releasing from cliffs during sun breaks in the afternoon.
We measured 200 cms of snow above the mid January crust at 6,400 on E aspects in sheltered terrain. This reinforces that this layer would be difficult for a single skier to trigger. Looking across the valley however, we could see several large avalanches that likely occurred on the mid January layer in the last few days. The thin trigger points in these slabs suggest that should one find a sufficiently shallow area of the snowpack, they could still trigger large destructive slides.
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