Northwest Avalanche Center

Observation: Public

All Observations

Observation Details

Name:
Irene Henninger
Observation Date:
February 13, 2021
Submitted:
February 13, 2021
Zone or Region:
West Central
Activity:
Skiing/Snowboarding
Location:
South side of Mountain Loop Highway

Signs of Unstable Snow

Did you see shooting cracks? 
Yes, Isolated
Did you experience collapsing or whumpfing? 
Yes, Isolated

Observations

We just barely made it into the below treeline forecast range, but even so we were travelling carefully through the featured terrain to avoid the steep wind loaded slopes based on the cracking and tiny avalanches we were getting on very small features. New snow was about a foot deep over the stout melt freeze crust, but some areas were stripped back to the crust while others were loaded to nearly a foot and a half deep. There were signs of previous loading where we were, although active transport was minimal throughout the day. Temps were a few degrees below freezing and light snow was falling most of the time.

Media

This tiny failure occurred as we were skiing over a very small feature. Note how quickly the snow depth changes and forms into a thicker, reactive wind slab.
This area whumphed as it was entered, and cracks were visible around most of the area. It was a surprise because the snow depths were so variable- from nearly stripped back to the crust in some areas, to 1 foot in others.
Skin track failures
Cracking at 3200ft on an E aspect.

Advanced Observations

Observed Avalanche Problem #1: 
Wind Slab
Comments: 
We only travelled to 3300 ft on primarily east aspects. There was highly variable and inconsistent wind loading, but in areas where it was present the snow was touchy, reactive to skier triggers on the underlying MFcr, even at that low an elevation. Its depths varied from 4" to 15" They formed no larger than a size 1 avalanche. No natural avalanches occurred.
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