Observation: NWAC Forecaster

All Observations

Basic Information

Observation Details

Observation Date:
January 7, 2023
Submitted:
January 7, 2023
Observer:
NWAC Forecaster - Dallas Glass
Zone or Region:
Snoqualmie Pass
Location:
Commonwealth Basin/Cave Ridge (All aspects near and below treeline. (3000-5300ft) )

Signs of Unstable Snow

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

Media/Attachments

This small wind loaded test slopes cracked and failed. The slab was 4-6 inches thick (10-15cm).
Blowing snow and drifts can be used to help anticipate wind loaded features
Snow profile on a N aspect at 5150ft on Cave Ridge
Snow profile on a SE aspect at 5000ft on Cave Ridge.
Open creeks at lower elevations are still a hazard.
Two old piles of avalanche debris were seen on the S face of Snoqualmie Mt. 5500ft

Advanced Information

Weather Summary

Cloud Cover:
Obscured
Temperature:
30°F
Wind:
Moderate , SE
New/Recent Snowfall:
New snow (HN24) 2inch (5cm).

Calm, mild, and damp below treeline gave way to cold and stormy up higher.

I found 2 older piles of avalanche debris on the S side of Snoqulamie Mt. It was hard to tell how old these slides were, but no crowns were visible

Snowpack Observations

Below Treeline:
In a word... variable. Snow surfaces ranged from soft to wet to frozen to breakable. The lower elevation snowpack appears very strong with 12-15 inches (30-40)cm over the Christmas Crust.

Near Treeline:
Sheltered: 18-24 inches (45-60cm) of settled snow was found on all aspects over the Christmas Crust. While I could still identify inter-storm layers, they did not fail in any snowpack tests. The upper snowpack was right-side up and generally strong.

Wind-Affected: While the predominant wind direction was from the SE, wind-loaded pockets were seen on nearly all aspects. Blowing snow, scoured slopes, sharp wind lips, fresh drifts, and deep pillow-like drifts were all observed. While not all test slopes failed, the ones that did produce shallow 4-6 inch (10-15cm) deep slabs.
Blowing snow was also observed higher in the terrain with significant loading onto SW-W facing slopes.

Other:
Open creeks continue to be a hazard with few crossing available.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Wind Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
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