New snow instabilities in the Ruby Range

CBAC CBAC Observations

Date of Observation: 01/22/2022
Name: Zach Guy and Evan Ross

Zone: Northwest Mountains
Route Description: Traveled on easterly and southerly aspects in Poverty Gulch to 12,500 ft.

Observed avalanche activity: Yes
Avalanches: Numerous loose snow avalanches in the new snow ran today or yesterday, most were very small. A few ran far enough/ gained enough volume to pose a hazard in consequential terrain, D1 in size. We skier triggered a handful of similar sluffs, along with a few of a wetter variety on sunnier aspects. Near mountain top, we triggered a few small soft slabs by tossing rocks onto a suspect north-facing slope. Those slopes had seen just enough wind to add some cohesion to the new snow, and the slabs failed on the weak, faceted snow at the storm interface.
Weather: Clear skies. Calm winds until we reached an exposed ridgeline at 12,000′, where there was just enough wind to cause light drifting.
Snowpack: About 4″ of new, low-density snow. Our obs focused on documenting the freshly buried near-surface weak layers that have been forming this month. At near and above treeline elevations, the January weak layer is characterized by small grained facets, often capped by either wind or sun crusts. The facets are generally fist hard, .5 mm in size, with a few up to .7 mm. Capping crusts are spatially variable depending on wind and sun exposure. Wind crusts vary in thickness and tend to be hard (1F or harder) throughout much of the alpine terrain. Sun crusts are generally soft (4F) and collapsible, up to 2cm thick, on E to SE aspects. They presumably get a bit thicker on due south and southwest, where we had limited travels.

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