Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
December 17, 2021
Submitted:
December 17, 2021
Observer:
NWAC Forecaster - Josh Hirshberg
Zone or Region:
Stevens Pass
Location:
Henry Creek (2880-4550ft, NW-NE)

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
None Experienced
Collapsing? 
None Experienced

Media/Attachments

Surface hoar, the equivalent of frozen dew, seen here formed needle-like grains on vegetation. We found a few of these mixed in with surface facets and rimed stellars on the snow surface. Henry Creek, 4,000ft, NW

Advanced Information

Weather Summary

Cloud Cover:
Obscured
Wind:
Calm
New/Recent Snowfall:
HN trace

Valley fog obscured visibility. No wind transport. Evidence of E valley winds and previous transport from 12/15.

None observed. We attempted to trigger loose dry avalanches on test slopes without luck, though we weren't in very steep terrain.

Snowpack Observations

Height of snow @ 4,500ft: 70-110cm.
Coverage is still shallow at low elevations and east of the pass.
Snow surfaces continue to weaken. Found a mix of forms from very small near-surface facets, to graupel (3mm) and rimed stellars (1.0mm), and occasional needle-like surface hoar.
We weren't able to get high enough to find pre-December snow in the lower snowpack.

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