Northwest Avalanche Center - Public Observation

Name:

Jeff Hambelton

Observation Date:

February 8, 2023

Submitted:

February 8, 2023

Zone or Region:

West North

Activity:

Snowmobiling/Snowbiking

Location:

Canyon Creek SnoPark - Bearpaw Area

Did you observe any avalanches?

Yes

Comments:

Per their statements, a snowmobiler triggered the slide at approximately 9 am, approaching the slope from the side and below. The slab propagated above the rider, approximately 300' wide, 100' tall and traveled approximated 300' downslope. The slope is 40+ degrees at its steepest. The rider's partner witnessed the slide, saw the rider disappear in the debris, and was able to locate the rider with a hand above the surface and dig his partner out.

None reported

A profile obtained at the crown of the avalanche revealed a stout melt-freeze crust (1 cm) at the bed surface with a widely visible layer of 1-2 mm graupel grains (deposited at the start of the storm on Saturday, Feb 4) visible on the crust surface. The slab was 40-60 cm thick, top half was 4F, bottom half was 1F (see photo).

A second riding group reported a human triggered slab avalanche later in the afternoon in an adjacent zone, around 2 pm. The avalanche occurred in terrain with a similar aspect and elevation as the earlier slide. They reported that the slide was larger than the earlier slide, propagating several hundred feet wide and traveling over the initial runout and several hundred feet into the valley below. Unverified estimates suggest a size 2.5 avalanche with a crown around 50 cm +/-. The slide was reportedly triggered as the snowboarder made a heel-side turn at a convexity in the terrain. The rider escaped without further incident, and no one was in the runout below.