Avalanche Forecast
Regions: Flathead, Lizard, Lizard-Flathead.
Conditions are expected to remain primed for human-triggered avalanches. Triggering is most likely at treeline and above on wind-loaded slopes.
Confidence
Moderate
Avalanche Summary
On Tuesday, several natural cornice releases were observed. Only one of these triggered a small slab on the slope below. Explosives triggered a variety of storm slabs, wind slabs, cornices, and one persistent slab.
On Monday, numerous naturally triggered (by either wind or cornice fall) storm slab avalanches up to size 2.5 were reported on primarily northerly aspects in the alpine.
Snowpack Summary
Up to 60 cm of recent snow and southwest winds formed slabs reactive to human triggers.
In most areas, the storm snow rests on a melt-freeze crust, except for high-elevation north and east-facing slopes.
A persistent weak layer of surface hoar or facets from late January is buried 100 to 150 cm. Rocky slopes with a convex shape on northerly and easterly facing aspects at treeline and above are the most likely places to trigger this layer.
The lower snowpack is generally well-settled and strong.
Weather Summary
Wednesday Night
Mostly cloudy with a chance of light flurries. 20 to 40 km/h southwest ridgetop winds. Treeline temperature -5 °C. Freezing level near valley bottom.
Thursday
Cloudy with snowfall 5-15 cm. 20 to 40 km/h southwest ridgetop winds. Treeline temperature -3 °C. Freezing level 1500 m.
Friday
Cloudy with snowfall 10-20 cm. 30 to 50 km/h southwest ridgetop winds. Treeline temperature -2 °C. Freezing level 1700 m.
Saturday
A mix of sun and cloud. 15 to 30 km/h west ridgetop winds. Treeline temperature -3 °C. Freezing level 1600 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Avoid steep, rocky, and wind-affected areas where triggering slabs is more likely.
Avalanche Problems
Storm Slabs
Up to 60 cm of recent snow and southwest winds formed reactive storm slabs. These slabs will be most reactive on wind-loaded slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1 - 2.5
Persistent Slabs
A persistent weak layer of surface hoar or facets is buried 80 to 150 cm. Rocky slopes with a convex shape on northerly and easterly facing aspects at treeline and above are the most likely places to trigger this layer.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3