Avalanche Forecast
Regions: Bull, Elkford East, Elkford West, Flathead, Lizard, Lizard-Flathead, South Rockies.
Watch for wind slab reactivity at higher elevations.
The complex snowpack continues to demand thoughtful terrain selection to avoid triggering a very large avalanche.
Keep up the safe travel choices and avoid shallow rocky start zones.
Confidence
Moderate
Avalanche Summary
Avalanche control on Saturday produced size 1 to 2 avalanches that were created from storm slabs and wind slabs.
Although they have not produced avalanches in the last few days, instabilities from the deep persistent slab still exist and should be assumed to be lurking in the backcountry.
Snowpack Summary
Soft thin wind slabs have developed in exposed areas. It has been blending into older wind-affected surfaces above 1800 to 2000 m. Below this elevation, recent snow has settled on a melt-freeze crust that developed earlier this month.
A crust/facet layer (2 to 15 cm thick at treeline elevation) is down 50 to 90 cm. Where it's thickest, it caps the settled and consolidated mid-snowpack.
Another crust/facet layer is down 70 to 150 cm. Below this crust, the basal snowpack is weak and faceted. The total snowpack depth ranges between 120 and 250 cm.
Weather Summary
Sunday Night
Clear with increasing cloud, trace to 3 cm accumulation, 10 to 20 km/h west winds, treelin temperatures -9 C.
Monday
Cloudy with clearing later in the day, up to 4 cm accumulation, 20 to 30 km/h southwest wind, treeline temperatures -11 C.
Tuesday
A mix of sun and cloud, trace accumulation, 15 to 20 km/h southwest wind, treeline temperatures -10 C.
Wednesday
Cloudy with sunny breaks and clearing off in the afternoon, potential trace accumulation, 10 km/h west wind gusting to 30, treeline temperatures -10 to -5 C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
Avalanche Problems
Wind Slabs
Wind slabs exist in the alpine and can be found on leeward slopes and along ridge crests at higher elevations. Expect them to remain reactive to human triggering.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1.5
Deep Persistent Slabs
Faceted grains make up the basal snowpack and are gaining strength very slowly. This layer has been relatively quiet recently but can still be triggered with a heavier load, like a cornice fall for example. and at areas with a thinner snowpack. Any avalanche triggered this deep will likely be large and destructive. It should remain on your radar for now.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 2 - 3