Avalanche: Turnagain

Location: Cornbiscuit

Route & General Observations

We skied the N facing Cornbiscuit chutes today as well as attempting to ski one of the south facing gulleys into Bertha Creek.

First, upon arriving at the upper Cornbiscuit chute, the chute had already partially slid naturally in the storm snow onto the lower apron. A pair of pits in undisturbed snow at 3,400′ N aspect at the entrance to the chute proper produced the same result: ECTN8 at the bottom of the storm snow interface and ECTN15 at the interface between last weekend’s snow and the windboard underlying it. Height of pit: 1 meter, snow depth: 2 meters. Upon skiing the chute, it slid again, with a slab breaking at the the first skier’s feet, 200 feet below the entrance, 6 – 8 inches deep, 75 feet wide. Impossible to tell how far it ran with the poor light and weather. In the basin below the first skier triggered a 200 ft wide, 4-6 inch deep storm slab on the side of the old lateral moraine. This terrain feature is only 20 ft tall, so length was very limited. Of note, this bank-slope did not slide when we skinned across it. Given the different nature of this slide and location in the localized basin depression I think it probably ran on BSH.

Second, we moved to the S facing gulley meeting at the top of the previously skied chute. Ski cutting the crossloaded drift triggered a slide 100 feet wide, 1 foot deep, impossible to determine length due to poor visibility. We descended 300 feet, but stopped and reascended due to cracking and small slabs (up to 1 ft thick) breaking below the new bed surface.

Third, we skied the 2nd Cornbiscuit N chute. It had not slid, nor did it slide with repeated ski cutting. However, there was high volume sloughing even for the 4th person in the group.

Fourth, we skied the 3rd Cornbiscuit N chute. It had not slid, nor did it slide at the entrance with ski cutting. However, like the first chute, the first skier triggered a slab at their feet 200 feet below the entrance. The slide was 75 feet wide, 1 foot deep and ran well into the apron. Again, high volume sloughing even for the 4th person on the slope.

All slide between 2900 and 3600 feet. No pictures due to challenging visibility.

Avalanche Details
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Trigger SkierRemote Trigger0
Avalanche Type Soft SlabAspect Unknown
ElevationunknownSlope Angleunknown
Crown DepthunknownWidthunknown
Vertical Rununknown  
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
Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

snowing, calm