Observation: Turnagain

Location: Silvertip Valley

Route & General Observations

Stayed on lower angle terrain, but got into the alpine area.

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?Yes
Collapsing (Whumphing)?Yes
Cracking (Shooting cracks)?No
Observer Comments

Widespread significant whumphing from 1,700 up to 2,200ft. Many whumphs had a diameter of 40-60 meters and would connect between skiers. Whumphs large enough in size to flush ptarmigan 80 meters away. Stayed off slopes steeper than 25deg, and stayed away from runouts of steeper slopes. Turned around more than 1mile short of our goal.

We saw many crowns from recent soft slab avalanches on the face of the long N-S rib to the East of Silvertip Creek. Crowns looked to be shallow (few inches deep), and in the 2,900-3,100ft elevation band. Some slides went several hundred vertical feet. Debris piles were minimal, and generally dispersed into the alder above the valley floor.

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

Mostly cloudy/foggy with some quick breaks of blue sky. 0-5mph winds. High 20's F.

Snow surface

600' - 1,400' dust on crust. thin snowpack

1,400' - 1,700' new powder snow built from 1" to almost 8", sometimes more than 1ft on top of a supportive but breakable crust.

1,700' - 2,200' 1ft+ of new fluffy dry powder on top of a supportive crust, above a thick and collapsing layer of facets. whumphing everywhere.