Avalanche

Avalanche: Catherine's Pass

Greg GagneSalt Lake
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Quick report

Slope Angle
45°

Avalanche

Slab Width
18 m
Weak Layer
Facets
Trigger Type
Skier
Vertical Fall
122 m
Avalanche Type
Soft Slab
Slab Thickness
30 cm
Start Zone Aspect
Northeast
Avalanche Problem
Persistent Weak Layer
Start Zone Elevation
3170 m

This avalanche occurred sometime during the morning of December 24 on a steep northeast-facing, wind-loaded slope. There were two adjacent tracks above the crown, so it is possible the riders intentionally triggered the avalanche. What caught my attention was the 30-35 cm deep slab was not that strong - at most 4F+ hard and just above a faceted layer that was buried on December 13. The persistent weak layer (PWL) is so weak that in some places, the slab has to be just "strong enough" to avalanche.