Avalanche Forecast
Regions: Flathead, Lizard, Lizard-Flathead.
6:30 AM Update: Storm delayed until this evening.
Temperatures will still rise and persistent slabs may become more reactive.
Confidence
Low
Avalanche Summary
On Thursday, a size 1.5 naturally-triggered wind slab was reported in the Lizard Range on a north-facing slope.
Additionally, numerous, size 1 to 2 dry and wet loose avalanches, both natural- and rider-triggered have been running in steep terrain over the past few days.
On Tuesday there were two reports of size 1.5 skier and snowmobile triggered persistent slab avalanches in the alpine. See details in this MIN here as well as this MIN.
Snowpack Summary
Around 5 to 15 cm of new snow is expected to fall overnight and through Saturday, with the highest amounts forecast for the Lizard Range. This will add to the current 20 to 30 cm of more recent snow overlying 30 to 60 cm of facets. Below this is a persistent weak layer consisting of a crust or facets and surface hoar buried in late January. The mid and lower snowpack is generally well settled, with no other layers of concern.
Weather Summary
Friday Night
Cloudy with 5 to 10 cm of snow. 30 to 40 km/h southwest ridgetop wind. Treeline temperature -4 °C.
Saturday
Cloudy with 2 to 5 cm of snow. 30 to 40 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level rising to 1800 m.
Sunday
Mostly cloudy with 15 to 25 cm of snow or rain below 1700 m. 40 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level rising to 2000 m.
Monday
Mainly cloudy with 0 to 5 cm of snow or rain below 1400 m. 30 to 50 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level rising to 1700 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
- Pay attention to the wind; once it starts to blow, sensitive wind slabs are likely to form.
- Be especially cautious as you transition into wind-affected terrain.
Avalanche Problems
Persistent Slabs
The late January weak layer may get overloaded by a combination of new snow, wind and warming. When in doubt, stick to more conservative terrain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 2.5
Wind Slabs
Up to 15 cm of new snow combined with southwesterly winds may build reactive new wind slabs at upper elevations. Watch for wind-loaded areas, especially near ridge crests and rollovers.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2