Avalanche Forecast
Regions: Northwest Inland.
A storm will impact the region, bringing snow and strong wind. Slabs may form rapidly over the day and load buried weak layers. Conservative terrain travel is recommended.
Confidence
Moderate - Forecast precipitation (either snow or rain) amounts are uncertain.
Weather Forecast
THURSDAY NIGHT: Cloudy with snowfall, accumulation 5 to 15 cm, 40 km/h southwest wind, alpine temperature -6 C.
FRIDAY: Cloudy with snowfall, accumulation 5 to 15 cm, 40 southwest wind, alpine temperature -5 C, freezing level rising to 1000 m.
SATURDAY: Cloudy with snowfall, accumulation 5 to 10 cm, 60 km/h southwest wind, alpine temperature -8 C.
SUNDAY: Cloudy with snowfall, accumulation 5 to 10 cm, 60 km/h southwest wind, alpine temperature -9 C.
Avalanche Summary
A small but hard wind slab avalanche was remotely triggered by a rider on Wednesday, occurring on a west aspect around 1700 m from reverse loading.
Avalanche activity may spike during the incoming storm, once sufficient snow loads the buried weak layers described in the snowpack summary. Avalanches could be triggered naturally or by riders and the result may be very destructive.
Snowpack Summary
A storm is forecast to drop upwards of 30 cm of snow by Friday afternoon. Storm and wind slabs may form rapidly during the storm and they may overly a weak and feathery surface hoar layer, particularly in sheltered treeline and below treeline terrain.
Around 50 to 100 cm deep, a hard melt-freeze crust from early December may have weak and sugary faceted grains around it. The last reported avalanche activity on this layer was December 17 and 19. The likelihood of triggering this layer may increase during the storm.
The early-November melt-freeze crust may be found near the base of the snowpack and have weak faceted grains around it. The last reported avalanche activity was near Smithers on December 22. The most likely terrain to trigger it would be in shallow and rocky alpine areas.
Terrain and Travel
- Watch for fresh storm slabs building throughout the day.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Avalanche Problems
Storm Slabs
The incoming storm is expected to form new slabs over the day, with the most snowfall expected in the west of the region. The thickest deposits are expected to be in exposed terrain up high, as the snow will fall with strong southwest wind. The snow may overly a weak layer of surface hoar so the snow could slide easily.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Persistent Slabs
A weak layer may exist around 50 to 100 cm deep, composed of weak and sugary faceted grains above a hard melt-freeze crust. It has been over a week since the last reported avalanche on this layer, but the likelihood of triggering it may increase during this stormy period.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1.5 - 2.5
Deep Persistent Slabs
The base of the snowpack has been reported as being composed of weak and sugary faceted grains for much of the region. The most likely area to trigger it would be on slopes where the snowpack is thin, such as near rocky outcrops.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely - Possible
Expected Size: 2.5 - 3.5