…and another large remote triggered slide.

CBAC CBAC Observations

Date of Observation: 02/28/2022
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Baxter Basin area. Traveled on various aspects to 11,500 ft.

Observed avalanche activity: Yes
Avalanches: A pair of snowmobilers riding tandem on one sled remotely triggered a large persistent slab on an east aspect near treeline. The associated crack wrapped about 900 feet around the terrain feature, but the slab only released about 200 feet wide. The slab was 70 cm thick, mostly F to 4F with about 8 cm of 1F near the bottom in the dust layer. The weak layer was…. you guessed it…the mid-February dry spell layer: 1 to 1.5 mm facets, fist+ hard. The snowmobilers triggered the slide after several passes adjacent to the slope and were not in harm’s way when it released.
We also intentionally triggered a couple of small slabs of similar thickness below treeline on small steep test features. A handful of D1 wet loose slides ran either today or yesterday at all elevations on E to SE to SW aspects.
Weather: Warm.
Snowpack: Obvious signs of instability were hit or miss without a particular rhyme or reason. We noted one rumbling collapse on an easterly aspect around 10,500 ft that shot cracks across some small supported rollovers without producing any slides. I noted a handful of other shooting cracks while riding around on lower angle terrain further down valley near Schuykill Ridge, and some of the steep rollovers that we tested produced cracking while more often they did not. Lots of large rollerballs on steep southerly aspects, surfaces on the sunbaked aspects were getting warm and wet.