Avalanche Forecast
Regions: Flathead, Lizard, Lizard-Flathead.
Increasing winds on Tuesday will create new and reactive wind slabs.
Confidence
Moderate
Avalanche Summary
On Sunday, numerous wind slab avalanches up to size 2 occurred, including both natural and explosive-triggered. These avalanches were observed in alpine and treeline terrain on various aspects, with depths ranging from 10 to 40 cm.
An encouraging observation is that none of these avalanches triggered a step-down avalanche on layers deeper in the snowpack.
Snowpack Summary
Strong winds on Tuesday will further redistribute the recent 20 cm of snow from the weekend, promoting wind slab development in lee and cross-loaded terrain.
Settled powder snow remains in wind-sheltered terrain, while a thin melt-freeze crust exists below approximately 1600 m.
The mid and lower snowpack is generally well-settled and stable.
Snow depths at treeline range from 120 to 180 cm.
Weather Summary
Monday Night
Mostly cloudy. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -3 °C.
Tuesday
Cloud building through the day with 0 to 2 cm of snow. 50 to 70 km/h southwest ridgetop wind. Treeline temperature -1 °C.
Wednesday
Mostly cloudy. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -7 °C.
Thursday
Mostly cloudy with 2 to 5 cm of snow. 30 to 50 km/h southwest ridgetop wind. Treeline temperature -5 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid lee and cross-loaded slopes in the alpine.
- Wind slabs are most reactive during their formation.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
Avalanche Problems
Wind Slabs
Strong winds on Tuesday will continue to form reactive wind slabs in lee and cross-loaded terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely - Very Likely
Expected Size: 1 - 2.5