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Professional Observation

       

Basic Information

Observation Details

Observation Date:
February 20, 2023
Submitted:
February 21, 2023
Observer:
Everett Phillips | ESAC Forecaster
Zone or Region:
Pine Creek
Location:
Pine Creek - Tungstar Bowls

Signs of Unstable Snow

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

Key Points

Went up Pine Creek for a tour in the Tungstar Bowls with the goal of getting into some higher alpine terrain and continuing to dial in the distribution of weak layers in the top half meter of the snowpack.

  • Ski penetration is less than 5cm except on protected north aspects below treeline. Ski crampons were used for most of the ascent.
  • Faceting in the upper snowpack on northerly aspects is widespread. It was observed from 8000′ up to 12500′. In most areas it is covered by a variety of strong surface layers including thin melt-freeze crusts, wind crusts, sastrugi and wind slab less than 30cm making it mostly supportable for skis.
  • In isolated areas where the facets are well developed and covered by a pencil hard 25cm slab porpagation was observed in the ECT (see attached profile). These areas are near and above treeline in north and north-east facing terrain that is wind protected and prone to loading from SW winds.
  • Gathering clouds and upper elevation north east winds limited warming air temperatures. I did not observe any signs of wet snow instability in Pine Creek today

 

 

Media

NE, 12000', Tungstar Bowls.
~ 15cm of soft cold snow in portected areas as low as 7400'
20230220 Pine Creek: Variations in snow surface within the path and terrain feature scale above treeline. Wind scoured, wind loaded, wind hardened and weak faceted surface snow (skin track).
Small pocket of wind slab that released around the last wind loading event on 2/14. It stepped down another 20cm into an older wind slab and facet combo. Small and isolated situation for now.
N, 9400' Crown profile of a small wind slab avlanche that stepped down another 20cm into older snow.
Oblique angle of a small avlanche from the 2/14 cycle that included small isolated pockets that broke on faceted layers in the upper snowpack. The blocks in the debris are a good reminder of the force of even a small avalanche.
20230220 Pine Creek: Variations in snow surface within the path and terrain feature scale above treeline. Wind scoured, wind loaded, wind hardened and weak faceted surface snow (skin track).
ECTP21 down 25cm, NE, 12000', 40 dgree slope, Pine Creek.

Advanced Information

Weather Summary

Cloud Cover:
Mostly Cloudy
Temperature:
22F @ 12,300' 2:00 PM
Wind:
Moderate , NE

Increasing cloud cover and a high elevation north wind limited warming in N facing terrain in Pine Creek today.

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