Avalanche: Turnagain

Location: Seattle Ridge

Date:
Observer:
Route & General Observations

After hosting a rescue workshop at the motorized lot we headed up to Seattle Ridge to see how the 2-3′ of new storm snow is stabilizing.

Avalanche Details
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Trigger CorniceAvalanche Type Unknown
Aspect WestElevationunknown
Slope AngleunknownCrown Depthunknown
WidthunknownVertical Rununknown
Avalanche Details

Cornice fall triggered by a snowmachine. Otherwise shallow 4-6" wind slabs on steep slopes. We did not see any significant large avalanche activity that we were expecting. However, most of the steep slopes were not touched.

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

Recent avalanches and cornice fall as noted above.

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

Snowing heavily 10am-noon. ~2" of snow accumulation. By 1pm skies broke up for a beautiful partly cloudy day. Winds were calm below the ridge then light from the NE on the ridge. Temperatures were close to 32F at 1,000'.

Snow surface

8" of dense new snow at 1,000'. Snow becomes much drier and deeper with elevation. At 2,500' there was 2-3' of soft settled but wind drifted snow along the ridgeline.

Snowpack

We dug one pit to look at the new/old snow interface at 2,600' on a NE aspect that was a bit wind affected. New snow was 40cm (16") deep, a bit wind scoured, results: ECTN 14 RP 5" down hardness change (wind slab), ECTN 25 RP 16" down on buried surface hoar at the new/old interface. These results point to a stabilizing snowpack. Although it is only one pit, it was nice to see that the buried surface hoar and weak old snow under the storm snow is bonding. Hopefully this is occurring many other places...

Photos & Video
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