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Eastern Sierra Avalanche Center

Professional Observation

       

Basic Information

Observation Details

Observation Date:
March 6, 2023
Submitted:
March 7, 2023
Observer:
Everett Phillips | ESAC Forecaster
Zone or Region:
Convict Creek
Location:
Mt. Aggie Wind Effect

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced

No signs of instability observed. One recent avalanche that looks like the work of the Feb. PWL (see below).

Key Points

In Convict Creek, wind more than snowfall seems to have been the dominant weather factor in the last storm. There is noticeably less snow between Morrison and McGee now than there was a week ago. Bare ground, sastrugi, fossil tracks and avalanche crowns have been unearthed by 100 mph wind over the past 48 hours. Travel was difficult in all but the most protected areas due to a mixture of old melt freeze crusts and sastrgui in low angle terrain. The exceptions are north faces which are fat and look to hold smooth if not soft snow.

 

Media

Scattered snow showers back along the crest in the PM
Cornice formation below treeline
Melt Freeze crust on S aspects re-exposed by extreme winds, tranisitoning to soft wind deposits on N aspects
In McGee Creek N facing terrain accumulated more snow than any other aspect in the previous storm.

Advanced Information

Weather Summary

Cloud Cover:
Partly Cloudy
Temperature:
15 F
Wind:
Light , E

Scattered snow showers and light to moderate wind along ridges in the afternoon. Cold.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Comments Photo
1 Past 48 hours Mt. Baldwin
N 11,000'
D2 2' N-Natural Suspected release on the Feb. PWL during the March 4-5th loading event. This is the kind of terrain where activity has been observed during periods when avlanche activity on the layer was isolated - Steep N facing and protected from wind and sun by surrounding terrain.
N, 11000' Convict Creek

Snowpack Observations

At 9700′ on a sparsely treed W aspect with 30 degree slope I found HS~250cm and the Feb. PWL down 85cm. 4F+ 1.5mm FCxr in two 3cm layers separated by a 5cm faceted wind board. Slab above average hardness 1F. PWL did not show up in an ECT. PST 90/120 End.

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