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Eastern Sierra Avalanche Center

Professional Observation

       

Basic Information

Observation Details

Observation Date:
December 11, 2021
Submitted:
December 12, 2021
Observer:
Josh Feinberg | Key Observer
Zone or Region:
Virginia Creek
Location:
Red Lake Bowl - Black Mtn

Signs of Unstable Snow

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

Snow Stability

Stability Rating: 
Very Good
Confidence in Rating: 
High
Stability Trend: 
Steady

Key Points

3-4″ of new snow seems to have fallen on Wednesday morning here.  Many places were stripped by wind to the old firm snow surface, and only slightly greater amounts found in deposition/catchment areas. Overall total snow depth 0-2.5ft.

SW winds increased throughout the morning up high up to strong, with some visible snow transport that seemed to be sublimating more than depositing over high ridges.

Variable surfaces from extremely firm and slick, some patches of ice even, to soft snow over facets in sheltered areas and soft snow over crusts of varying thickness… very little breakable at least!

No current stability concerns where I travelled today, but the firm surfaces will make for a good bed surface for avalanches to slide on during the large incoming storm. In widespread areas the upper-most underlying loose sugary facet layer appears to be consistently the weakest (whether buried under the crust of the old snow surface or just under the new snow without a crust ontop).  This facet layer will be quite a concerning weak layer with the incoming snow load.  A large avalanche could also possibly step down to the deeper firmer layer of facets.

 

 

 

 

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Weather Summary

Cloud Cover:
Mostly Cloudy

A much warmer day than yesterday with above freezing temperatures just before noon at 10,000′.

Snowpack Observations

Drove to the end of the VA Lakes Rd (9,800′) and skinned up Red Lake Bowl up to the easterly facing ridge top of Black Mtn (11,600′).  Much less new snowfall here from the Wednesday storm than around Mammoth, previous wind effects above treeline however appear to be much greater.  Lakes were quite frozen, with a thin snow cover.  Many places of challenging skinning conditions with the firm old surface layer either being exposed or buried by a few inches of soft snow.  Ski crampons would definitely have been useful, and ended up using boot crampons for the final few hundred feet to the ridgeline, even though the slope was not that steep.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Dry Loose
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
Layer Depth/Date: sugar
ct10000
None Specified
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