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Professional Observation

Basic Information

Observation Details

Observation Date:
February 19, 2020
Submitted:
February 19, 2020
Observer:
SAC - Davis
Zone or Region:
Galena Summit and Eastern Mtns
Location:
4th of July - Blackman Peak

Signs of Unstable Snow

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

Snow Stability

Stability Rating: 
Good
Confidence in Rating: 
Moderate
Stability Trend: 
Steady

Bottom Line

Weak snow near the ground is still a concern. I'm afraid we're stuck with this problem until we solidly transition into a more "spring-like" snowpack.

Advanced Information

Weather Summary

Cloud Cover:
Clear
Temperature:
Inverted
Wind:
Calm

Calm wind and clear skies. The -23 F start at the truck did (thankfully) warmup considerably as I climbed into 4th of July. It was T-shirt skinning weather at mid and upper elevations. Settled snow depths from the last storm ranged from 10-15 cm.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Comments Photo
1 Older than a week Blackman Peak
NW 9,900' 		D2.5 Old deep slab. I couldn't make out the crown but the flanks were thick. None

There were relatively few avalanches here during last weekend's storm. A few D1.5 debris piles but much less activity than in the Sawtooths. There were only a few D1-D1.5 wet loose avalanches of note due to the recent warming from the sun.

Snowpack Observations

9,500’, SSE (160 deg.), HS 135 cm:
Snow depths ranged from 110-145 cm in this area. The upper pack was a layer cake of four knife hard melt-freeze crusts with no obvious weak layers. The lower pack held a stiff (1F) slab over 32 cm of facets near the ground. The facets at the ground were well bonded (4F+) but the layer 10 cm up from the ground was still very weak (Fist 3 mm facets).

Lots of wind in the exposed alpine scoured ridges and left a patchwork of hard slabs.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Persistent Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
 Layer Depth/Date: Near the ground.
This layer is still very weak. PST 25/125 End on 3 mm Facets

I did not encounter any reactive wind slabs. I saw very few D1-D1.5 wet loose from the previous day.

Terrain Use

With a partner, I would have considered steep lines with a more consistently deep snowpack. The more scoured, rocky, terrain with variable snow depths and hard slabs was still easily spooky enough to avoid.

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