Avalanche: Turnagain

Location: Bertha Creek (Turnagain flats)

Route & General Observations

Field day in the flats, south of the motorized lot. Great day for an avalanche class as it was quite easy to see/ experience storm slab/ persistent slab instabilities where we were, in no consequence terrain.

Avalanche Details
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Trigger SnowmachinerRemote Trigger No
Avalanche Type Soft SlabAspect West
Elevation 900ftSlope Angle 35deg
Crown Depth 22inWidth 50ft
Vertical Rununknown  
Avalanche Details

Multiple storm slabs triggered on small test slopes in the flats, south of the motorized lot.

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)?Yes
Observer Comments

Whumpfing, shooting cracks and recent avalanches.... the trifecta!

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

5 deg F at 1,000'. Sunny. winds were calm in the flats. Large plumes visible on peaks in Portage Valley, Placer Valley Twentymile Valley, and Seattle ridge. Blowing from NNW.

Snow surface

Deep, unconsolidated storm snow. Very little wind effect at this elevation thru Turnagain Pass today.


Loc: Near Bertha Creek, south of moto lot
Ele: 900'
Asp: West
slope: 16 deg.
Test results: EXTP12-17 x 5

Consistent failure and propagation on the top of the January facets.

Photos & Video
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