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Professional Observation

       

Basic Information

Observation Details

Observation Date:
April 4, 2023
Submitted:
April 4, 2023
Observer:
Everett Phillips | ESAC Forecaster
Zone or Region:
Mammoth Lakes
Location:
Punta Bardini

Signs of Unstable Snow

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

Key Points

Went for a short tour in the Sherwins today to take a look at recent crust/facet interfaces. No signs of instability.

Media

Very little blowing snow on mid-elevation peaks. Snow was being driven over the meadows on the approach from the propane tanks and plumes were visible on the highest peaks. Isolated blowing snow today.
Old Crown on a steep ENE slope at 9600'. Nearby stabiltity tests did not intdicate instability despite the presence of the PWL. A good example of how difficult this problem has been to assesss,
4/4/23 Punta Bardini surface conditions NW 8500'

Advanced Information

Weather Summary

Cloud Cover:
Clear
Temperature:
20F
Wind:
Light , NW

Avalanche Observations

Despite the clear April skies,  the day felt wintry due to northwest winds and cold air temperatures.

Snowpack Observations

My tour stayed below treeline on mostly north aspects up to 9600′:

Ski pen was between 5 and 20cm. At lower elevations, and on sun and wind exposed slopes, I was skining in a partly supportable melt-freeze crust with just a few centimeters of windblown snow from yesterday strom. On steeper northerly pitches above 9000′ the crusts gave way to settled snow. HS was between 330cm and 400+cm.

I dug quick test pits throughout my tour on NE, N, NW and W aspects. I found three crusts in the upper snowpack. The first was at the surface and was never fully supportable (although I did not travel on southerly slopes today). The second and third are the 3/29 and 3/19 layers. I was alble to track these throughout my tour. They wer usually down 30 and 60cm respectively fro mthe surface, althout they were found up to 80cm deep in wond laoded areas.

I tested the layer with CT’s and ECT’s.  I only had one concerning result: 9600′ on a 25 degree NE slope; CTH Sudden Planer down 80cm on the 3/19 layer (.5mm FCsf and FCxr) of rounding facets. This test result was adjactent to an old crown from last week and meant to be representative of that slope. No result in the ECT.

In this area the peristent slab problem seems to be isolated and stubborn to trigger.

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