Observation: Turnagain

Location: Sunburst

Route & General Observations

Toured up to 3100′ to get an eye on recent and mid-storm avalanche activity, and to try to collect some more info concerning the New Year’s crust. We saw the aftermath of a lot of avalanches that had released sometime during the middle of the storm over the past two days. This included multiple natural avalanches on Seattle Ridge, a very large avalanche that covered most of the west face of Magnum, and multiple avalanches ocurring on slope angles in the low 30’s on Sunburst and Taylor Pass. All of this seemed to occur mid-storm, with debris piles and crowns covered by a few inches of new and wind-drifted snow. All of the activity appeared to be within the storm snow or at the interface between new and old snow.


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)?No
Cracking (Shooting cracks)?No
Observer Comments

Widespread natural cycle with large avalanches on Seattle Ridge, Tincan Proper, the Library, Sunburst, Taylor Pass, and Magnum. The slide on Magnum was probably 800' wide, 1000' vertical, and debris was over 10' deep in some places. One of the avalanches on Sunburst had parts of the start zone with slope angles at 32 degrees, and it is a slope that a lot of folks tend to think of as a safer slope. All of the activity appeared to fail on storm snow interfaces.

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

Clouds were in and out, with some periods of sun in the middle of the day. A low cloud in the valleys began to move in around noon. Winds were calm with the occasional light breeze.

Snow surface

Breakable crust up to 1" thick at elevations up to just above 1000'. Storm snow totals were 1-1.5', with wind loaded areas in the range of 2-3' deep.


For most of the area, the only noteworthy layer in the upper 2-3' of the snowpack was a very thin (~2mm) and brittle crust that formed when temperatures were warm on Wednesday afternoon. This was anywhere from 6-18" deep, depending on whether slopes had been scoured by wind or not. The New Year's crust was as shallow as 2' deep on a wind-scoured ridge, and upwards of 6' deep where winds had been loading snow. This layer gave mixed results in our pit tests, and none of the recent avalanches looked to have stepped down to this layer. More snowpit info in attached snow profile.

Photos & Video
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