Observation: Public
Observation Details
Name:
Dallas GlassObservation Date:
February 23, 2023Submitted:
February 23, 2023Zone or Region:
Snoqualmie PassActivity:
Skiing/SnowboardingLocation:
Snoqualmie MtTriggered Avalanches
Did you trigger any avalanches?
YesWas it intentional?
YesAvalanche Type:
Hard SlabSize:
Size 1: Relatively harmless to peopleElevation:
5200Aspect:
SWComments:
We intentionally triggered several small wind slabs on test slopes. Depths ranged from 4-12" deep.Observed Avalanches
Did you observe any avalanches?
YesAvalanche Type:
Soft SlabSize:
Size 2: Could bury, injure, or kill a personElevation:
5400ftAspect:
EComments:
This natural slab avalanche occurred between noon on 2/22 and 730am on 2/23. The terrain and shadow lines make it difficult to see the full extent of the avalanche.Signs of Unstable Snow
Did you see shooting cracks?
Yes, IsolatedDid you experience collapsing or whumpfing?
NoObservations
Weather: Very cold temperatures. Light to moderate SE winds. Few to scattered thin clouds.
Upper Snowpack: The snowpack had settled ~4-6 in (10-15cm) since yesterday. Even with that settlement, the snow surface was still very light, dry, and fluffy. We found 18-20in (45-50cm) of right-side-up snow over heavier wetter snow from earlier in the storm (Mon 2/20). We did not find any significant weak layers in the storm snow.
Wind-affected snow was found even below treeline. However, we did not see any real wind slabs until we were breaking out of the darker forest. We found blowing snow, textured surfaces, rime, drifts, and large cornices all highlighting wind-loaded slopes. Firmer slabs up to 12 in (30cm) thick were found. They often produced long (8-12ft) shooting cracks or even, in a few cases, small avalanches.
Despite the sunny weather, cold temperatures, thin clouds, and a stiff breeze kept the snow surface cold and dry even on steep southerly slopes mid-day.
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