Sensitive windslabs on Mammoth Crest

AVALANCHE OBSERVATION
Crystal Chute

Drainage:

Submission Info
Ryan Huetter
Volunteer Observer
Saturday, December 8, 2018 - 12:00pm
Avalanche Type: 
Slab
Slope: 
45degrees
Trigger type: 
Skier
Crown Height: 
Less than 1 ft
Aspect: 
Northeast
Weak Layer: 
Old Snow
Avalanche Width: 
30ft.
Terrain: 
Near Treeline
Elevation: 
10 500ft.
Bed Surface: 
Old Snow
Avalanche Length: 
20ft.
Number of similar avalanches: 
1
More detailed information about the avalanche: 

SS-ASc-R4-D1 Soft slabs triggered artificially by cornice drop (1), and ski cut (1)

Approached the right hand entrance of Crystal Chute from Red Cone. Top of chute beginning to grow a cornice, though still only 2'-3' tall, with uncorniced entrances available. A cornice cut with a ski caused a small 20'x15' pocket to pull out, crown depth 8", entraining most of the soft surface snow lower in the chute. Further left, a hard bounce at the ridgeline caused a larger pocket to slide, and propagated into the adjacent left chute as well. Crown height 10". 

Both were intentional in order to open the chute to skiing, and occured directly below the cornice lip. We avoided skiing Jaws and nearby slopes due to senstivity, rockier consequences and more convex entrances with less margin for error. 

Avalanche Photos: 
Blowing Snow: 
Yes
Cloud Cover: 
25% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Moderate
Precipitation: 
None
Air temperature trend: 
Static
Wind Direction: 
Southwest
Accumulation rate: 
None
More detailed information about the weather: 

Increasing winds at ridgetops with blowing snow, beginning to reload slope and fill in tracks in between our two laps. 

Crystal Chute 37° 35' 17.2104" N, 119° 1' 24.5208" W
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