Previously established skin track up through trees into the base of the large cirque from Blue Lake Trail-head. Descents near the skin-track (1st) and to the west of the skin track (2nd).
Dec. 30, 2018, 1:30 p.m. PST
Weather: Snow flurries in the morning. Light to moderate snow in the early afternoon. Clearing by mid-afternoon. Calm winds at Washington Pass became light to moderate out of the west in the NTL areas.
Snowpack: 12/29 rain crust was present up to around 5500' elevation.
Area Description: A generally south-facing drainage and cirque accessed to the N-NW of Blue Lake Trail-head. Our party traveled in BTL and NTL terrain with views into ATL terrain at the head of the drainage.
Avalanches: Around 11:30 we observed a party on the ridge who had recently triggered a large avalanche minutes before we arrived in the basin. The avalanche broke widely across terrain features and was triggered around 7000 ft, just off the ridge-line on a wind-loaded slope. E or E-SE aspect. Around 13:30, the first member of our party of 5 triggered a large avalanche also on an E aspect at 6500 ft while traversing with skins on. The avalanche knocked him over and he lost a pole and a ski. Both were shallowly buried and recovered 10 ft and 100 ft, respectively, down the slope. The avalanche was estimated to be 75 ft wide, ran 400-500 ft vertical and over 1000 ft horizontally, and broke near the ridge about 75 ft above him. The crown was on a 38-40 degree slope while the triggering location was in the 30-33 degree range (estimated). The slide released on layer of 5-6 mm buried surface hoar at a depth of 2 feet in this wind-loaded location. Our party safely returned to Blue Lake following the incident, noting shooting cracks on steeper test slopes throughout the descent.
Observation by Robert Hahn
Did you see any avalanches? Yes
Did you trigger any avalanches? Yes
Was anyone caught in an Avalanche? Yes