Lee Vining area -East Peak -poor structure on upper E aspects

SNOWPACK OBSERVATION
East Peak
Submission Info
Forecaster
Wednesday, March 18, 2020 - 1:00pm
Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
37° 54' 23.94" N, 119° 11' 47.1876" W
Snowpit Observations
More detailed information about the snowpack: 

It was 11F @ 1500 @ 11606ft

It was a lengthy skin up through the new snow to East Peak. There were two notable natural avalanches that had slid during the storm. One slide almost hit Gibbs Lake from the NE shoulder of Gibbs peak, no crowns visible today, but slide looked to be more of a loose snow point release that was in the D2 category. Another slide was indeed a wind slab avalanche that had slid from 11800ft, East aspect from one of the main gullies of East Peak. It ran 1600ft vertical and was R2D2 bordering on D3, but there really was not that much volume in the debris field. Some short lengths of the crown were visible in the multiple starting zone chute terrain and looked to be from 1-2ft in height.

There was a good period of sun in the early part of the day that really helped cook any slope facing the sun. Cloudy weather with very light snow flurries filled most of the afternoon  and the mountains above 10500ft were obscured when I left at 430pm.

The east gullies that had not slid on East Peak were some of the most awful breakable wind board I’ve skied for some time. It was not supportable and sucked you into the soft storm snow that was encapsulated beneath this 5cm Pencil hard surface. The structure of the underlying snowpack in these high east facing gullies is composed of primarily rotten faceted snow that has been sitting there all winter and now is blanketed with this past weekend’s storm.  Although I did not get any shooting cracks, wind slab moving down slope or collapsing while climbing and descending from 11606ft, the snow pit on the other hand showed some poor structure and a propagating result on a ECT 45cm below the surface. The pit was at 11200ft on an East aspect with HS=150cm and failures occurring within a 15cm faceted layer residing on a thin melt/freeze crust.

I got minor collapsing primarily in low angle terrain in the trees today. There was no active wind loading of snow where I was on East Peak, but Mt Gibbs looked to have active transport on the upper reaches of the north face.

 

Snowpit or crown profile photo or graph: 
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