Avalanche: Turnagain

Location: Cornbiscuit uptrack

Route & General Observations

One of AAS Level 1 groups traveled up to 1900′ on Cornbiscuit to learn about snowpack and see how the new snow was behaving on top of the various crusts. Many people out enjoying the first sunny day in a while, but we did not see any human triggered avalanches, only some dry loose sluffs in steeper terrain.

Avalanche Details
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Trigger UnknownRemote Trigger Unknown
Avalanche Type UnknownAspect Unknown
ElevationunknownSlope Angleunknown
Crown DepthunknownWidthunknown
Vertical Rununknown  
Avalanche Details

We observed few fresh crowns from the last storm cycle back on Magnum ridgeline - most likely natural wind slabs or initiated by cornice breaks.

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)?No
Observer Comments

We observed localized collapsing in few spots while putting in skin track at lower elevations. .

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

Clear skies, awesome visibility all day.
Temps started at teens, warmed midday, but then dropped again to 11F at the end of the day at the parking lot.
No wind or precipitation.

Snow surface

~30cm soft new snow to travel up and down - surprisingly dry despite relatively warm temps during the latest storms..Some rimed particles mixed in on the surface.
There was no wind impact on the surface at the elevations and aspects we traveled in, but we were able to see across to Seattle Ridge where the upper elevation looked pretty hammered and scalloped.


We dug at three different locations to learn about the snow layers and to conduct basic snowpack tests.
Total snowpack heights ~120cm @ 1200', ~150cm @1500' and ~180cm@1900'.
Oh boy, all the crusts kept us scratching our heads trying to date them and observing how they disappear and appear at different elevations.
All in all, snowpack showed good stability. Our numerous column tests took lot of force to get anything collapse and very low propagation propensity. It was easy to observe the large hardness differences within snowpack (facets on the crusts) so we will still keep thinking about the persistent problems in the midpack.
On the west aspects (1200' & 1500') we identified a weak interface on a crust 40-55cm from the surface but some overdrive forcing got facets on Halloween crust 90cm down to fail
On the north aspect (1900') the weak layer was on a crust 35cm from the surface but results were surprisingly mid..

Photos & Video
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