Observation: Public
Observation Details
Name:
Colin WisemanObservation Date:
December 28, 2020Submitted:
December 28, 2020Zone or Region:
West NorthActivity:
Skiing/SnowboardingLocation:
Shuksan Arm/Mt BakerObserved Avalanches
Did you observe any avalanches?
YesAvalanche Type:
Hard SlabSize:
Size 2: Could bury, injure, or kill a personElevation:
Near treelineAspect:
NEComments:
The wind slab, by my best guess, was roughly 80-100 feet wide, 1-2 feet deep, on a NNE aspect, and ran fast. Five riders had already descended the ridgeline rider's left on a slightly more northerly aspect. The sixth person entered further rider's right, aired in, and triggered the slab in a broad depression, which propagated to the tracks in the more featured terrain to his left. He was briefly caught before self arresting on a tree 100 yards downslope. The avalanche triggered another slide another hundred yards or so below and it ran to the valley without catching the others. It happened around 9:30 am in one of the few sunny spots on the slope.Photo:
Signs of Unstable Snow
None reported
Observations
Although the NWAC forecast was "moderate" they did note tension in the snowpack, wind loading from the SW after two feet of snowfall, and a slick bed surface. Yesterday saw a remote trigger of a similar sized avalanche on an isolated terrain feature. My own observations from the past few days, including shooting cracks and snow that felt a bit "hollow," aligned with these concerns.
Media
