April Pow and Slabs
Observed Apr 2, 2023, 12:01 p.m. PDT · Selkirks
This report was submitted with an older form.
Quick report
- Comment
- Skied alpine and TL terrain on NE to NW aspects from 2350m to 2000m in the selkirks, west of the kokanee range. 15-25cm of new snow fell in the April 1st storm, forming a soft unreactive 4F slab. Evidence of natural windslab activity during the storm from this new snow in immediate ridgetop lees. HN produced loose dry with skier traffic, that arrested in steep terrain and didn't entrain more mass. 1 skier accidental suspected persistent slab occurred, see avalanche description.
- Weather
- Cloudy, Stormy, Windy
- Ride type
- Alpine slopes
- Riding quality
- Amazing
- Snow conditions
- Deep powder
- Avalanche conditions
- Avalanche condition snow
Avalanche report
- Comment
- Skier crossing a alpine bowl feature triggered a slab at 2350m on a NW aspect. Trigger point was near a rocky outcrop, where ski pen increased (suspect due to facets around the rock). Suspected failure plane is March 14 FC and SH. Failure plane was down 45-55cm, with a 30cm 1F slab immediately above and 15-25 cm of HN over that. Slab cracked slowly underfoot, and spread 20m behind the skier. Lower down the slope, 2 other slabs released with the initial slab release. The other slabs were 250m in width, down 20-50cm. All debris arrested mid track, running 100-150m from their respective crowns. No skier involvement. Dialed it back to lower angle terrain out of immediate lees. Hand shears prior to the avalanche showed easy to hard planar and break shears down 45-55cm. FC and SH were observed on the shear surface. The results of this should have warranted a more in depth conversation do the destructive potential of the slab and risk involved with exposing the group to this peice of terrain. Good spacing and travel habits were used, but if the slope had released remotely above the skier, this could have been much worse. Photo shows trigger point on the left hand side of the upper most crown.
- Run length
- 100
- Slab width
- 250
- Trigger type
- Skier
- Wind exposure
- Lee slope
- Avalanche size
- 2.5
- Slab thickness
- 50
- Trigger sub type
- Accidental
- Start zone aspect
- NW
- Vegetation cover
- Open slope
- Start zone incline
- 34
- Avalanche character
- Persistent slab
- Crust near weak layer
- No
- Number of avalanches
- 1
- Start zone elevation
- 2350
- Weak layer burial date
- 2023-03-14
- Avalanche observation
- 12hrsAgo
- Weak layer crystal type
- Surface hoar, Facets
- Start zone elevation band
- Alp
- Avalanche occurrence datetime
- 2023-04-02T08:00:00.000Z
Incident report
- Description
- no involvement, see avalanche tab
- Group activity
- Skiing
- Snow depth trigger point
- Deep
- Terrain shape trigger point
- Planar