Avalanche Forecast
Issued: Jan 21st, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
shorton,
Avalanche Canada
Enjoy the clear weather but remember triggering avalanches remains possible on steep and rocky slopes.
Summary
Confidence
Moderate - Confidence is due to a stable weather pattern; little change is expected for several days. Uncertainty is due to the fact that deep persistent slabs are particularly difficult to forecast.
Weather Forecast
THURSDAY NIGHT: Partly cloudy, light north wind, treeline temperatures around -8 C.
FRIDAY: Sunny, light north wind, treeline temperatures around -6 C.
SATURDAY: Increasing cloud during the day, light northwest wind, treeline temperatures around -6 C.
SUNDAY: Cloudy with isolated flurries and up to 5 cm of snow, moderate northwest wind, treeline temperatures around -10 C.
Avalanche Summary
Extreme wind on Tuesday resulted in a natural cycle of wind slab avalanches. Wind slabs should be gaining strength, but may still be possible to trigger on certain slopes.
Deep persistent slab avalanche activity has been more sporadic (as it often is). A size 2.5 avalanche was reported from Skilokis over the weekend, that appeared to be triggered by a cornice and failed on a facet/crust layer. Explosives triggered a few size 2.5 avalanches near the southern boundary of the region on Jan 7 as well as some very large size 3-4 avalanches at Ningunsaw earlier this week. These are reminders of this low-probability / high-consequence scenario.
Snowpack Summary
10-20 cm of snow from earlier this week has been redistributed by strong southwest wind. Since then temperatures have cooled leaving wind slabs in the alpine, unconsolidated powder in sheltered terrain, and a shallowly buried crust below 1000 m. A few isolated surface hoar layers were observed forming in early January and would now be 30-60 cm deep if preserved, but these layers have not been reported in any recent snowpack or avalanche observations. The main snowpack feature we are tracking is two crusts with weak faceted snow in the lower snowpack. The upper crust is 70-140 cm deep in the Smithers area and has shown signs of being possible to trigger from shallow areas. The deeper crust is near the bottom of the snowpack and is most likely to trigger from steep rocky slopes (especially in thinner ranges like the Babines).
Terrain and Travel
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
- Conditions may have improved, but be mindful that deep instabilities are still present.
- Be especially cautious near rock outcroppings, on steep convexities and anywhere the snowpack feels thinner than average.
Problems
Wind Slabs
Recent storm snow is strengthening, but reactive wind slabs could still be found on steep alpine slopes and along ridgetops.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
In shallow snowpack areas, weak faceted snow can be found around crusts roughly 100 cm below the surface. Human triggered slabs above this weak layer are possible on isolated shallow rocky slopes. The most recent avalanches on these layers have been reported east of the Bulkey Valley and at Ningunsaw.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 22nd, 2021 4:00PM
