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Eastern Sierra Avalanche Center

Professional Observation

       

Basic Information

Observation Details

Observation Date:
January 11, 2023
Submitted:
January 12, 2023
Observer:
Steve Mace | ESAC Forecaster
Zone or Region:
Mammoth Lakes
Location:
Panorama dome

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
None Experienced

Key Points

Went for an afternoon walk in the Mill city area looking for signs of settlement within the storm snow as well as to assess the sensitivity of recent wind deposits.

  • Storm snow is settling very quickly. It never ceases to amaze me how fast 70 ” of snow can become supportive. Skipen averaged around boot top throughout my tour.
  • I avoided large start zones intentionally today however I was able to initiate small wind slabs, sensitive cornice features and long shooting cracks on small test slopes in the area.
  • I found evidence of relatively thin (3-10″) deposits I expect developed in the last 12 hrs that i would describe as sensitive.
  • I also found deeper deposits approaching a meeter in depth that i would describe as reactive. Several of my shooing cracks initiated deeper in the pack.
  • I dug a quick pit to get an idea of the structure of these deeper wind deposits and found 1f -4f slab on top of F+ snow.  My stability tests confirmed this layer to be reactive. (ECTp 13 down 60 5 cm from the surface. repeated several times failure between 13 and 15 taps.)

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Weather Summary

Cloud Cover:
Overcast
Temperature:
25
Wind:
Light , SW

Overcast skies and lingering showers persisted throughout the day. Winds in the Mammoth area underperformed the forecast with mostly light to moderate speeds observed. 

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