Avalanche Forecast
Regions: Bonnington, Grohman, Kootenay Boundary, Kootenay Pass, Moyie, Norns, Rossland, South Okanagan, Ymir.
7 am update: Strong overnight winds from the northeast have likely reverse-loaded fresh wind slabs into atypical terrain features at upper elevations. Keep an eye out for signs of instability like "whumfing", shooting cracks and avalanche activity. There is some uncertainty in reactivity and distribution of buried weak layers.
Confidence
Moderate
Avalanche Summary
Over the past few days several skier triggered avalanches up to size 2.5 have been reported. many of these avalanches failed on weak layers from February and January and occurred at treeline. a few skier triggered wind slabs have also been reported , these avalanches have been near ridge crests on north and east aspects.
Snowpack Summary
Storm totals from the past week average 40 to 60 cm. Expect to find wind slabs on all aspects due to shifting wind direction. This storm snow sits over heavily wind affected surfaces at all elevations.
A layer of surface hoar can be found on shaded slopes, and a sun crust on sun affected slopes buried 40 to 70 cm deep. Another layer from January is buried up to 50 cm below this. These layers has been noted as a failure plane for some avalanche activity.
Otherwise, the snowpack is generally well consolidated and bonding. The lower snowpack includes a layer of weak sugary crystals near the ground. These facets are slowly gaining strength and have not produced recent avalanche activity. We continue to track the layer and watch for any signs that it could wake up and produce very large avalanches.
Weather Summary
Saturday Night
Mostly cloudy with the possibility of light flurries bringing a few centimeters of new snow. Moderate southeast winds and a low of -11°C at 1800 m.
Sunday
Mostly cloudy with the possibility of light flurries bringing a few centimeters of new snow. Light southeast winds and a high of -6°C at 1800 m.
Monday
A mix of sun and cloud with the possibility of light flurries bringing trace amounts of new snow. Light southerly winds and a high of -6°C at 1800 m.
Tuesday
Mostly sunny with no new snow expected. Light southwest winds and a high of -6°C at 1800 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Keep in mind that human triggering potential persists as natural avalanching tapers off.
- Persistent slabs have potential to pull back to lower angle terrain.
- Surface hoar distribution is highly variable. Avoid generalizing your observations.
Avalanche Problems
Wind Slabs
Strong northeast winds overnight have formed fresh wind slabs on exposed terrain at treeline and above on a variety of aspects due to recent winds shifting from southwest to northeast.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely
Expected Size: 1 - 2
Persistent Slabs
There are two layers of concern in the upper and mid pack. These layers are generally made up of facets and surface hoar but on south aspects a crust can be found. These layers are most likely to be triggered on sparsely treed slopes at treeline and below.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1 - 2.5