Recreational Observation

West Slopes North - Canadian Border to Skagit River

Jan. 9, 2020, 9:15 a.m. PST

Weather: broken clouds, cool to cold, still

Snowpack: boot-top dry loose powder or rain saturated, refrozen pack from recent storm cycle. No signs of instability; obvious large cornices on east facing aspects of ridges predicting wind loading beneath; no surface wind slab signs (our plan was to avoid east facing potential wind loaded start zones)

Area Description: South Sub-summit of Mt Herman

Avalanches: bootpacking the last 25 vertical feet to the sub-summit staying 10 feet back from the cornice edge (miscalculated the vulnerable weak point) 2 climbers triggered a large (1-2 school buses sized) cornice block to fall onto the 35-40 degree east facing slope; climbers fell 30-60 vertical feet. One climber was packed into a small moat rim around a rock, upright against the shielding rock with minimal trauma, as the avalanche of the wind loaded new snow and the broken cornice block poured past him and carried the second climber, who was able to swim to stay on top, another 200 VF downslope; the entrained snow ran very fast on the rain crust and ran at least 500 VF. No injuries despite the significant height of fall. A cautionary tale as we thought we were giving the cornice the wide berth it commanded. Learned from a friend that the cornice had earlier developed a cleft 10 feet back as it sagged, which didn't fail in the rain event but was completely filled in. We broke the cornice off at this unseen weakness, which broke on the rock ledge of the sub-summit block, as we bounced off it on the sudden ride down.

Observation by Pete Beglin

Latitude: 48.863404

Longitude: -121.702396

Did you see any avalanches? Yes

Did you trigger any avalanches? Yes

Was anyone caught in an Avalanche? Yes