Avalanche Forecast
Issued: Jan 2nd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Persistent Slabs and Deep Persistent Slabs.
cgarritty,
Avalanche Canada
The storm hammering the coast isn't expected to push far inland, but be ready to step back from avalanche terrain if you see accumulations exceeding forecast amounts
Summary
Confidence
Weather Forecast
SATURDAY NIGHT: Cloudy with flurries bringing about 5 cm of new snow. Strong southwest winds.
SUNDAY: Cloudy with continuing flurries bringing 5-10 cm of new snow. Strong southwest winds, easing by evening. Alpine high temperatures around -5.
MONDAY: Cloudy with scattered flurries and a trace of new snow. Moderate to strong south winds. Alpine high temperatures around -6.
TUESDAY: Cloudy with scattered flurries bringing a trace of new snow before increasing overnight. Moderate to strong southwest winds. Alpine high temperatures around -4.
Avalanche Summary
Avalanche activity is expected to spike during this stormy period, as slabs form and 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
Around 20 cm of snow has accumulated in much of the region so far and the snow is forecast to continue to fall through Sunday. Storm totals could reach 35 cm or more by Sunday afternoon. Storm and wind slabs are likely forming rapidly 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 around December 21. The likelihood of triggering this layer is expected to increase during this stormy period.
The early-November melt-freeze crust may be found near the base of the snowpack and may have weak faceted grains around it. The last reported avalanche activity on this layer 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.
- Avoid all avalanche terrain during periods of heavy loading from new snow and wind.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Problems
Storm Slabs
We are in the midst of a stormy period with new slabs building at all elevations. The snow may be reactive in sheltered terrain where it could overlie a weak layer of surface hoar. Strong wind from the southwest will create thicker and touchier deposits in lee terrain features at higher elevations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A weak layer composed of weak and sugary faceted grains above a hard melt-freeze crust exists around 60 to 100 cm deep. 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
Expected Size
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 this deep weak layer would be on slopes where the snowpack is thin or transitions quickly from thin to thick, such as near rocky outcrops.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 3rd, 2021 4:00PM
