Avalanche Forecast
Regions: Glacier.
We have an unusually weak and faceted snowpack at Rogers Pass.
Sticking to lower angled, supported slopes, and avoiding shallow rocky areas, will reduce your chances of triggering the deeper persistent weak layers.
Confidence
Moderate
Avalanche Summary
The steep terrain of the Macdonald gullies continue to spit out large natural avalanches daily. Notably, gully #6 produced a size 3 slab avalanches during a brief wind spike Thursday Morning.
There was a skier triggered slab avalanche on Avalanche Crest on Wednesday.
On Monday a size 2 avalanche was remotely triggered from a shallow snowpack area on Bruins Ridge. These types of spooky avalanches continue to be reported in nearby areas, and are causing anxiety amongst avalanche forecasters! Stay away from thin, rocky areas, and ensure no other skiers are below you before entering your line.
Snowpack Summary
The top 30cm of snow is low-density and provides great powder turns. Steeper SW and W aspects have a thin sun crust on the surface. Brief moderate Northerly winds on Friday may have created some wind effect in exposed areas at upper elevations.
The December 23rd facet interface, down ~70cm, is gaining strength, but remains a concern in shallow snowpack areas.
The November 17th facet/crust/surface hoar layer is still active in snowpack tests, exhibiting 'sudden collapse' or 'sudden planar' results, and producing isolated large avalanches in neighboring areas.
Weather Summary
Low pressure off the coast is trying to push some weather our way - but only barely succeeding. Sporadic light flurries could give us 5-10cm of accumulated snowfall by Sunday.
Tonight: Isolated flurries, Alpine Low -6*C. Light/gusty SW ridgetop wind.
Friday: Cloudy with isolated flurries. High -6*C. Light SW winds.
Saturday: Scattered flurries (5cm). Low -8*C, High -4*C. Light SW winds.
Sunday: Isolated flurries. Low -10*C, High -6*C. Light/gusty South wind.
Terrain and Travel Advice
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
Avalanche Problems
Deep Persistent Slabs
The Nov 17 layer, down 60-120cm, consists of facets, a rotting crust, and decomposing surface hoar. Though becoming less likely to trigger, the resulting avalanche would be quite destructive. Managing this type of problem requires a disciplined approach
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3.5
Persistent Slabs
30-60cm of settled storm snow buries the Dec 23 facet interface. This layer will be a concern in thin rocky areas, on convex rolls, or in areas where the snowpack is unsupported (pillows, hanging snow fields, etc.).
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Unlikely - Possible
Expected Size: 1 - 2.5