Avalanche Forecast
Regions: Flathead, Lizard, Lizard-Flathead.
Numerous rider triggered slab avalanches continue to be reported in this region.
Triggering is most likely at treeline and above on wind-loaded slopes.
Confidence
Moderate
Avalanche Summary
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.
Numerous skier triggered storm slabs up to size 2 were reported on primarily north and east aspects at all elevations.
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
Tuesday Night
Clear skies, 10 to 20 km/h southwest ridgetop winds, treeline temperature -10 °C, freezing level valley bottom.
Wednesday
Sunny, 10 to 20 km/h southwest ridgetop winds, treeline temperature -4 °C, freezing level 1600 m.
Thursday
Cloudy with isolated flurries, 3-10 cm, 20 to 30 km/h southwest ridgetop winds, treeline temperature -5 °C, freezing level 1600 m.
Friday
Cloudy with flurries, 5-10 cm snow, 30 to 40 km/h southwest ridgetop winds, treeline temperature -3 °C, freezing level 1700 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.
- Use small, low consequence slopes to test the bond of the new snow.
- 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.
- Avoid steep, sun-exposed slopes when the air temperature is warm or when solar radiation is strong.
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 and on sunny slopes during periods of strong solar radiation.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: 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
Loose Wet
Wet loose avalanches will become very likely when the sun comes out. Avoid overhead hazard from steep sunny slopes when the solar radiation is strong.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1 - 1.5