Observation: Chugach State Park

Location: Arctic Valley

Route & General Observations

Toured above Arctic Valley Ski Area to the saddle between Mount Gordon Lyon and Rendevous Peak. We observed pockets of wind slab near treeline and above tree line on E, S, and W facing terrain features. There was high variability throughout the zone with snowpack depths ranging from 5cm-50cm and with the wind stiffened slabs ranging from 1cm-20cm thick–all sitting on top of weak faceted snow to the ground.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?No
Collapsing (Whumphing)?Yes
Cracking (Shooting cracks)?Yes
Observer Comments

We observed widespread cracking as most remaining snow surfaces had been stiffened by the wind. As we approached the saddle on a W facing slope above treeline at 3,000ft elevation, whumphs were reported by both tour groups.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

Overcast skies, no precipitation, light NE winds, no blowing snow

Snow surface

Wind stiffened, pencil hard surface snow ranging from 1cm-20cm thick.


Variable wind-loading pattern and variable wind slab development. We found touchy 5cm pencil hard wind slabs and more stubborn 20cm wind slabs on various aspects near and above treeline. Snowpack tests on a 12 degree West facing slope at 3,000ft with both HS 27cm and HS 40cm confirmed repeatable CTE SC results on the interface between wind stiffened layers and weak basal facets.

Photos & Video
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