Observation: Turnagain

Location: Sunburst

Route & General Observations

Toured up Sunburst to check on the conditions of the wind effected snow at elevations above tree-line. We dug one pit at about 2200′ on a NW aspect. Skinning up the ridge was difficult due to the firm wind scoured snow which forced the skin track up the face. Skiing was great despite the slightly wind effected snow although we exercised extra caution in an attempt to not get ski tips hung up in some areas with a wind crust.

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)?Yes
Observer Comments

We saw some fresh looking debris in several gullies along the base of the SW aspect of Seattle ridge that looked like it was from small wind slabs releasing at the top of the gully. We couldn't see any crowns, but think they were likely filled in by subsequent wind loading. On some small test features at the top of treeline we triggered some shooting cracks on noticeably wind loaded features. It took a fair bit of effort to get them to release and the deepest pocket we found was only 6" deep.

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

Mostly sunny with scattered clouds. Light north winds were on and off throughout the day at Sunburst, across the valley winds on Seattle Ridge blew moderately at the start of the day where we witnessed snow transport. By mid-day all winds even in the alpine had died down and we did not notice any further snow transport on Turnagain pass.

Snow surface

Variable snow surfaces transitioned between wind scoured and loaded. Some surfaces were surprisingly soft while others were stiff making it easy to catch tips while skiing. In some areas we had about a 6-12" of light soft surface snow on top of a harder wind crust. In other locations the wind had been blown from the new/old snow interface exposing a hard surface crust.


We dug one pit at 2200' on a NW aspect, but otherwise were mostly focused on trying to test wind loaded pockets and get a sense for the wind effect on the surface conditions. We found one notable weak layer in our stability tests, which was a layer of facets about 1' deep, underneath some alternating thin wind slabs and soft snow. We had propagation in one extended column test on this weak layer (ECT P 25), which indicates that it could be a potentially concerning weak layer in the future. This weak layer is likely more of a problem in areas with recent wind loading where there is a stiffer slab on top of the facets.

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