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Avalanche: Turnagain

Location: Tincan Trees

Date:
Observer:
Route & General Observations

Tincan up to 2,300’ – storm day with intense precip and poor visibility

Avalanche Details
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Trigger SkierAvalanche Type0
Aspect WestElevation 2200ft
Slope Angle 40degCrown Depth 12in
Width 15ftVertical Run 30ft
Avalanche Details

Easily triggered ski cuts on steep test slopes. Slabs were barely forming and only found on wind loaded rolls.

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

Cracking on wind affected steep slopes no greater than 15’ long
Ski cuts produced 10-12” soft slabs on 40 degree test slopes (see video)

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

Snow, heavy at times, accumulation ~6” between 11am and 3pm
Rain/snow line steady @ 500ft
Moderate NE winds
Mild temps, 32 F @ 1,000’
Poor visibility

Snow surface

8-16” new snow total above 2,000’ with variability due to winds
12” total at road level by 3pm
Parking lots obs: Tincan 12”, Sunburst 6-8”, Johnson Pass 2”

Snowpack

Multiple hand shears on all aspects showed a lack of cohesion in the new snow (no slabs) and good bonding between the new snow and underlying surfaces.
Underlying surfaces - 3-4” crust above 2,000 , 3-12” wet layer 1,000’-2,000
Test result in a pit @ 2,100’ showed advanced melt freeze grains that were mostly in the melt phase (Fist hardness). This structure could cause problems in the form of new slabs stepping into this wet layer and producing deep wet loose avalanches. A major heat up or intense rain would precipitate this scenario. The presence of the crust at the present time is preventing this from happening.

Photos & Video
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