Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 4, 2022
Submitted:
January 4, 2022
Observer:
NWAC Forecaster - Josh Hirshberg
Zone or Region:
Stevens Pass
Location:
Skyline Lake area (S-E, 4050-5200ft)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced

Media/Attachments

A profile in the Skyline area. Overall, recent storm interfaces were bonding well. We targeted the Dec 29th and Solstice layers. E, 5150ft, Stevens Pass
A profile of the upper snowpack featuring the most recent storm interface from Jan 2nd, a lingeing interface of small facets from Dec 29th, and the dormant Solstice crust and associated facets. Skyline area, Stevens Pass, E, 5,150ft
Shallow point releases on a very steep slope. Stevens Pass, E, 4400ft
A crown of a very shallow (D1) storm slab avalanche at an interface formed in the past 12 hours. This avalanche occurred early on the morning of January 4th. Moonlight area, Stevens Pass, ESE, 5300ft 
The west faces of Rock and Howard mountains. Notice the features, scultped by recent westerly wind on the right shoulder of Rock Mtn.
Selecting our profile site, sheltered by towering trees. Skyline area, Stevens Pass, E, 5,150ft.

Advanced Information

Weather Summary

Cloud Cover:
Partly Cloudy
Wind:
Calm
New/Recent Snowfall:
HN24 5cm

Calm. Light snow in the early AM and picking up again by 14:30. Clearing from 9:30-12:30 with periods of FEW clouds and surprisingly strong sun.

Today's avalanches were in the top 5-10cm of surface snow. Saw a few very shallow natural storm slabs avalanches on steep banks and isolated features near and below treeline on S-E in the Skyline area. Possibly the shallowest slab avalanches I've ever seen. Two of these were at the ridge of Moonlight basin (SE, 5250ft) and likely ran in the early morning. Lower on the slope, there were a few very shallow natural loose dry avalanches on a very steep feature at 4,400ft, SE. A steep road bank near Hwy 2 and White Pine rd (S, 2300ft) produced a few wet loose avalanches by 12:30p. I saw very faint, obscured debris piles in the Berne Camp Chutes on Nason ridge likely from avalanches on Jan 2-3rd. Otherwise, I saw surprisingly little evidence of recent avalanches with very good visibility, though I imagine most recent debris was very soft and is now well-buried.

Snowpack Observations

Ski and boot penetration remains very deep. Most surfaces above 3,000ft seemed to stay dry despite the mid-morning sun. I suspect surface hoar may have been buried by the thin HN24, tho I couldn't confirm this.

In a profile at 5,150ft on an east aspect, I targeted the Dec 29th and Solstice layers. The Dec 29th interface ↓63cm produced sudden planar results (CTM SP) on 0.5mm facets, though an extended column didn't propagate. The interface was much less reactive in informal tests compared to Jan 3rd. I got no results with multiple deep tap tests on the Solstice crust ↓149cm. The adjacent facets are softer than surrounding layers, though surprisingly rounded. See profile images

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Wind Slab
Isolated
Specific
Widespread
 Comments: no blowing snow observed but good visibility allowed views of recent light to moderate wind drifting, primarily above treeline but also immediate to near treeline ridges. I didn't directly assess this problem for size or sensitivity. See photo of Rock mtn
Storm Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
 Layer Depth/Date: Jan 2nd, Jan 4
Comments: Aside from a few very shallow (5cm) naturals, interfaces in the top 45cm have become more difficult to trigger. At low to mid elevations, it would now take slopes near to 40* or unsupported features to trigger avalanches of consequence.
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