Avalanche: Turnagain

Location: Cornbiscuit

Route & General Observations

Standard route up Cornbiscuit to 1800′.

It was great to have a day of good visibility to see what carnage went on in the mountains over the past couple days of stormy weather. Lots of evidence of large avalanches during the storm.

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

First day of good visibility for the past couple of days, we saw many avalanches that had released during the storm, most of them the crowns had begun filling in or debris covered up with new snow. Most of them were D2's. Below is a list of the notable ones:

Magnum West Face- Largest we noticed. The majority of lookers left side of the west face slid and sent debris within 100' of the powerline below, D3. The looker's right side of the west face also avalanched, just not quite as big.

Cornbiscuit West face- Ran past the bench right at tree/alderline and onto the next bench below.
PMS bowl- Ran into the valley bottom between Magnum and Cornbiscuit. Possibly triggered by cornice fall.
Superbowl- Short glimpse of a distinct crown.
Multiple on the roadside of Seattle Ridge near the Bertha Creek Campground.

Unfortunately, with low photo quality and debris/crowns getting covered up, the only photo even remotely worth attaching is the PMS bowl avalanche.

Red Flags
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Observer Comments

Aside from the previous avalanches, we did not see any obvious signs of instability or any new avalanches.

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

Light wind from the E. Few clouds in the sky except towards Turnagain arm, which seemed to remain socked in for a majority of the day.

Snow surface

Supportable to breakable crust up to 1200'. Nice riding conditions above that.


We dug snowpits at 1800' on WNW aspect, and in our pit location, we found the snowpack had good structure, moderate strength, and low-moderate energy. Our Compression tests were failing about 1 foot down where dense storm snow overlaid softer snow, breaking with moderate force with moderate shear quality. We were getting breaks but no propagation on this layer in our ECTs. We dug below to the new/old interface (about 3 feet down!) but got no failures down there in our tests.

Photos & Video
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