Avalanche Forecast
Issued: Jan 31st, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Deep Persistent Slabs.
mconlan,
Avalanche Canada
Newly formed slabs will take time to strengthen, as they sit on a widespread weak layer. Conservative terrain travel is recommended.
Summary
Confidence
Weather Forecast
MONDAY NIGHT: Cloudy with snowfall, accumulation 1 to 3 cm, 20 to 30 km/h west wind, alpine temperature -14 C.
TUESDAY: Cloudy with snowfall then clearing, accumulation 1 to 3 cm, 20 to 30 km/h northwest wind, alpine temperature -14 C.
WEDNESDAY: Increasing clouds with afternoon snowfall, accumulation 1 to 3 cm, 20 to 40 km/h southwest wind, alpine temperature -19 C.
THURSDAY: Cloudy with snowfall, accumulation 5 to 10 cm, 20 to 40 km/h west wind, alpine temperature -13 C.
Avalanche Summary
Many storm slabs, wind slabs, and loose avalanches were triggered by riders on Sunday within the recent storm snow. The avalanches were most reactive where they sat on the surface hoar layer described in the snowpack summary.
Looking forward, human-triggering of avalanches may remain elevated, particularly where the recent snow overlies surface hoar.
Snowpack Summary
Around 30 to 50 cm of snow fell on the weekend with strong wind, forming new storm slabs in sheltered terrain and wind slabs in exposed terrain. These slabs overly a widespread layer of weak surface hoar crystals that was reported to be between 5 and 15 mm in size, most prominent in terrain sheltered from the wind. The snow overlies a melt-freeze crust on sun-exposed slopes.
A few other weak layers of surface hoar and faceted grains exist in the top metre of snow but are reported as hard to find.
The facet/crust layer that formed in early December is buried around 100 to 200 cm. The last reported avalanche was on January 28 in the north of the region. The snowpack structure remains and it is a low probability but high consequence problem. Check out the forecaster blog for more information.
Terrain and Travel
- Good day to make conservative terrain choices.
- Make observations and assess conditions continually as you travel.
- Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Problems
Storm Slabs
Between 30 and 50 cm of snow fell across the region, forming storm slabs in areas sheltered from the wind and wind slabs at in exposed terrain at higher elevations. These slabs are expected to remain reactive to riders, as they overly a widespread layer of surface hoar crystals, faceted grains, and/or a hard melt-freeze crust on sun-exposed slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
Weak faceted grains sit on a hard melt-freeze crust, buried around 100 to 200 cm deep. Although the likelihood of triggering this layer will reduce given the current weather trend, the snowpack structure remains. Any release on this layer would be highly consequential.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 1st, 2022 4:00PM
