Observation: NWAC Observer

All Observations

Basic Information

Observation Date:

December 8, 2022

Submitted:

December 8, 2022

Observer:

NWAC Observer - Willie Webster

Zone or Region:

East North

Location:

Hairpin Valley (West East and North aspects near and below treeline)

Recent Avalanches?

None Observed

Cracking?

None Experienced

Collapsing?

Isolated

Total snow height at 6500' was up to 180cm in places. The 3-5" of new snow is on a thin and dense 'wind skin' at this elevation and aspect.

an older avalanche crown on a West Northwest slope on Kangaroo Ridge. Unknown when this avalanche released.

settlement cone shows snowpack pulling away from snow on trees

New snow sits atop large surface hoar layer at 5370'

Advanced Information

Cloud Cover:

Overcast

Wind:

Light , SW

New/Recent Snowfall:

Three to five inches of new snow fell today.

Overcast skies all day with light snow flurries. Light winds seen at ridge tops.

Avalanche Observation Comments:

We spotted signs of avalanches from sometime in the last week. There was a small telltale avalanche track at the end of the hairpin valley. Higher above us we spotted an older crown. It isn't clear to me if these came down after the new snow of Nov. 30th, or if they were the product of wind transport on the 6th and 7th. The 4 inches of new snow from today obscures these older signs.

In the valley bottom we experienced a couple of hard-to-miss snow pack collapses which seemed to cover about 10 square meters. Also, Low in the hairpin valley we spotted large surface hoar crystals recently covered by the new snow. The buried surface hoar became smaller and harder to find as we ascended. Higher up near tree line, the new snow fell on a dense, but thin 'wind skin' surface. Digging a pit at 6480', on a NNE aspect, we found a 180cm deep snow pack. The late November crusts did not show a propensity for propagation at this particular location and depth. (ECTX and PST END 90/100 at 80cm). Overall, we experienced mixed signs from the snow pack which may indicate some noteworthy spacial variability.

Problem	Location	Distribution	Sensitivity	Size	Comments
Wind Slab	N E S W	Isolated Specific Widespread	Unreactive Stubborn Reactive Touchy	D1 D1.5 D2 D2.5 D3 D3.5 D4 D4.5 D5	Layer Depth/Date: 80cm Weak Layer(s): Nov 22, 2022 (FC)

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