Avalanche Forecast
Regions: Flathead, Lizard, Lizard-Flathead.
There is uncertainty with the speed of recovery of the snowpack. Maintain conservative terrain choices while we transition to a cooler weather pattern.
Confidence
Moderate
Avalanche Summary
Natural wet loose and natural cornice avalanche activity continued throughout the region on Thursday.
Large destructive avalanches were reported throughout the warm-up, involving persistent weak layers.
Temperatures are forecasted to cool, but rising daytime freezing levels may not fully develop a supportive crust; human triggering is possible.
Read the Forecaster Blog for an opportunity to reflect on this week's widespread avalanche activity.
Snowpack Summary
Roughly 10 to 15 cm will accumulate throughout the day over a breakable melt-freeze crust that becomes more supportive as you gain elevation.
The upper snowpack remains moist over a well-settled mid-pack.
A surface hoar or facet layer from late January is buried 100 to 180 cm deep on north and east aspects at treeline and above.
Weather Summary
Thursday Night
Cloudy with isolated flurries, 1 to 2 cm. 20 to 30 km/h southwest ridgetop winds. Treeline temperature -3 °C. Freezing level 1500 m.
Friday
Cloudy. Flurries, 8 to 12 cm. 20 to 30 km/h west ridgetop winds. Treeline temperature -1 °C. Freezing level 2000 m.
Saturday
Cloudy. Isolated flurries, 2 to 4 cm of snow. 20 to 30 southwest ridgetop wind. Treeline temperature -1 °C. Freezing level 1700 m.
Sunday
Cloudy. Isolated flurries, 2 cm. 5 to 10 km/h southwest ridgetop wind. Treeline temperature -2 °C. freezing level 1700 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be especially cautious as you transition into wind-affected terrain.
- Be aware of the potential for large avalanches due to buried weak layers.
- Cornice failures could trigger large and destructive avalanches.
Avalanche Problems
Wind Slabs
Convective flurries will be accompanied by moderate southwest wind redistributing storm snow in the alpine and treeline, developing wind slabs directly lee of high points and ridges
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2
Cornices
Cornices are large, looming and becoming weak with continued high freezing levels. A large cornice fall can be dangerous on its own, and can also trigger deep slabs on slopes below.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1.5 - 2.5
Persistent Slabs
A persistent weak layer of surface hoar or facets is buried 100 to 180 cm deep. Releases during the warm-up into high alpine terrain features keep this problem front of mind. Where no supportive crust has formed, it may still be triggered.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 1.5 - 2.5