Even though the overall hazard for persistent slab avalanche is rated at LOW, it is still worth some discussion.
Low hazard does not mean no hazard, and we expect there to be isolated locations and extreme terrain where human triggering a persistent slab may still be possible. Given the poor structure of the snowpack, it’s impossible to completely rule out any possibility of triggering an avalanche.
These locations will continue to be hard to identify. Locations with a shallower snowpack, on southeast to west aspects, less than a meter deep, combined with a large load such as a snowmachine will have a higher likelihood of triggering an avalanche.
In general, the structure at the bottom of the snowpack near the ground is improving. We are getting little to no propagation in our pits. We have not seen an avalanche since December 23rd. We have not observed any red flags in over a week.
12.24 Sastrugi and anti-tracks from several days of wind on lower Marmot looking across at Skyscraper
Snow surfaces are highly variable with numerous types of wind effect including thick supportable wind slab, thin breakable wind slab, soft deposited snow, sastrugi and anti tracks. These conditions will make any descent quite challenging. The snowpack depth varies from 10″ in scoured locations up to 6 feet deep on leeward aspects.
12.30 Conditions are highly variable in many locations. This picture is taken on Presidents Ridge.
12.30 Looking across at Arkose ridge and the Punk spines. This photo shows old crowns and a significant amount of terrain scoured to the ground from last week’s wind.
Sidewall pit profile on Presidents ridge. Despite how awful this looks, consider this. Facets under the wind slab are rounding, the rain crust is brittle and deteriorating, and basal facets are rounding and moist. The snowpack is graining strength slowly.
Very few people have been out recreating either because they know the conditions are harrowing or they were trapped with a snow berm blocking their driveway for several days. Either way, if you get out, we’d love to hear from you. Send us an observation!