Avalanche Occurrence

Photo of a very large triggered avalanche that resulted in a fatality on Friday, February 19th, near the head of Smiley Creek. The snowmobile track of the victim is visible in the center of the photo. The rider was carried downhill and found on the surface at the indicated location. The avalanche released on a south aspect at 9100'.

Observer:

SAC Forecaster

Verified by SAC?

Yes

Occurrence Date:

Feb 19, 2021 10:50 am (Exact)

Location:

Smiley Creek

Comments:

A snowmobiler triggered a very large avalanche while climbing the slope. His track is visible in the photos. He was caught and carried at least 600 vertical feet. The rider had deployed his airbag, was found by his partners on the surface, and was determined to have died due to injuries incurred during the avalanche. The avalanche ran into a well-defined gully that acted as a terrain trap, and debris piled up to an estimated depth of 20-30 feet. A full accident report will be completed in the upcoming days.

# of Avys:

Aspect:

S (S,SE)

Start Zone Elev:

9100ft

Size:

D2.5

Type:

HS-Hard Slab

Trigger:

AM-Snowmobile
u-Unintentional

Bed Surface:

O-Old Snow

Depth:

3.5ft

Width:

500ft

Vertical Fall:

1000ft

Weak Layer:

Jan 27, 2021 (FCsf)

Comments:

Start zone was not accessed to measure slope angle. Appeared to be in the upper 30 degree range. The avalanche failed on a very thin layer of facets atop a thick melt-freeze crust. This layer was buried on January 27, and on this slope had been subsequently loaded by new and wind-transported snow