Avalanche Forecast
Issued: Jan 7th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
ejones,
Avalanche Canada
Westerly winds may build slabs in exposed areas today.
Back off if you observe any signs of instability, such as avalanches, whumpfs, or shooting cracks.
Summary
Confidence
Avalanche Summary
On Saturday near Kispiox, size 1.5 avalanches were triggered by machines on steep cut banks at treeline, 60 and 80 cm deep.
Last week, backcountry users experienced whumpfs in the Babines, Grizzly Plateau, and around Hudson Bay Mountain.
These avalanches and the whumpfing are suspected to be failures of the buried surface hoar layers detailed in the Snowpack Summary. These observations suggest that humans could trigger avalanches where these layers remain intact.
Snowpack Summary
Another 5 cm today means up to 30 cm of soft snow exists in areas sheltered from the wind. Westerly winds will likely build reactive slabs on lee terrain features today.
At and below treeline, new snow overlies a melt-freeze crust.
Two or more preserved surface hoar layers can be found buried between 35 cm and 80 cm deep. These layers are most prominent at treeline and below treeline elevations above 1200 m, but they've also been observed in some alpine locations.
Snowpack depths at treeline vary across the region with generally deeper amounts (~150 cm) in the west and shallower (~80 cm) in the east.
Weather Summary
Sunday Night
Cloudy with trace snow, west alpine wind 20 to 40 km/h, treeline temperature -10 °C.
Monday
Cloudy with up to 5 cm of snow, west alpine wind 20 to 30 km/h, treeline temperature -8 ºC.
Tuesday
Mostly cloudy with trace snow, north alpine wind 10 to 30 km/h, treeline temperature -10 ºC.
Wednesday
A mix of sun and cloud, north alpine wind 10 to 30 km/h, treeline temperature -15 ºC.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
Problems
Wind Slabs
Watch for slabs on lee slopes and cross-loaded features. Wind slabs are likely to be more reactive on steep slopes near ridgetop and on convex rollovers. Assess for slabs before committing to large and consequential terrain features.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Several buried surface hoar layers may be found 35 to 80 cm deep. These layers only seem to be a problem at elevations above 1200 m.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 8th, 2024 4:00PM
