Public Observation #2022-673

Submitted:
March 8, 2022 12:50 PM
Observation Date:
March 5, 2022
Zone or Region:
Central Cascades
Activity:
Skiing/Snowboarding
Location:
Broken Top
Did you trigger any avalanches? 
Yes
Was it intentional? 
No
Avalanche Type:
Soft Slab
Size:
D1: Relatively harmless to people
Elevation:
8000
Aspect:
SW
Comments:
The Soft slab was 2-6in deep and propagated about 80 feet across the top of the chute. It slid about 500 vertical feet total and caused a sympathetic release of a side chute as well. The debris was mostly only 6in deep but was 1.5 feet at its deepest. The slide was powerful enough to knock and carry one our party members but not deep enough to bury.
Did you see shooting cracks? 
Yes
Did you experience collapsing or whumpfing? 
No
This Observation is a few days late, as we were out in the backcountry away from service till last night. On Saturday we toured into Broken Top. We found scoured snow surfaces until we reached the sw facing aspects in the Bowl. We went to boot pack up 3 o clock Couloir where there was between 2-6in of wind loaded snow laying on top of a stout rain crust.

Most of the snow was soft and unconsolidated but lightly slabby. We were bootpatcking on two inches of snow about to top out on the chute when the upper apron released on a foot step. One of our party members was swept off there feet when the slide came down. No one was injured. But our group was caught off guard with the instability of the new snow, the poor bonding and the propensity to slide of the shallow 2-6in wind slab. On Sunday and Monday this wind slab was still reactive and was failing in our ect's and hand shears on south and sw aspects. In areas I have traveled I found this rain crust to still be exposed as of Monday afternoon and it potentially could be the bed surface for this next storm to fall on.