Avalanche Forecast
Issued: Jan 18th, 2022 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.
jleblanc,
Avalanche Canada
Riding conditions are improving with new fresh snow. Take time to read about the various forecasted avalanches problems before heading into avalanche terrain.
Summary
Confidence
Weather Forecast
TUESDAY NIGHT: Partly cloudy, treeline high around -10 C, light variable wind, freezing level at valley bottom.
WEDNESDAY: Sunny periods, treeline high around -12 C, light westerly wind, freezing level at valley bottom.
THURSDAY: Flurries, treeline high around -5 C, strong southwesterly wind, freezing level rising to 1500 m.
FRIDAY: A mix of sun and clouds, treeline high around -5 C, light southwesterly wind, freezing level rising to 1500 m.
Avalanche Summary
Several small loose-dry avalanches (size 1) were observed on steep terrain near Mear Lake Tuesday. They released naturally in 20-25 cm of powder snow.
Recent deep persistent slab avalanches were reported in neighbouring regions (Lizard-Flathead and Waterton National Park) over the last few days. These human-triggered and natural avalanches failed on the early December crust and showed wide propagation. This evidence suggests the deep persistent slab problem is still a concern in the region.
Snowpack Summary
The region received between 10-25 cm of fresh dry snow Tuesday, which now overlies older surfaces like hard wind slabs or recent melt-freeze crust. The crust varies from thin/breakable to thick/supportive, according to the aspects and elevation. Under it, the snowpack consists of a variety of old surfaces, including soft snow in sheltered areas and wind slabs in exposed and open areas.
The most notable layer of concern in the snowpack is a crust that was formed in early December and is now typically down 80-150 cm. In the neighbouring Lizard-Flathead region, three very large avalanches were reported on this layer on Jan 13. This layer has created a tricky low likelihood, high consequence scenario which is best managed through conservative terrain choices and disciplined backcountry travel techniques.
Terrain and Travel
- Investigate the bond of the recent snow before committing to your line.
- Wind slabs may be poorly bonded to the underlying crust.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
Problems
Wind Slabs
Fresh/ soft slabs will likely develop on exposed slopes at higher elevations. Recent new snow may be hiding older /harder wind slabs that were easily visible before the snow fell. While these slabs may be thin, they could be poorly bonded to the underlying snow, so be extra cautious in lee terrain and convex rolls.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Deep Persistent Slabs
A deep persistent slab problem formed by a crust down 80-150 cm has created a low likelihood, high consequence scenario that is difficult to forecast. There has been an increase of avalanche reports on this layer since the past weekend. This old and deeply buried weak layer is one of the most challenging problems to predict and for people to safely manage in the backcountry. Our best advice is to avoid likely trigger spots such as steep, rocky slopes with a shallow or thin to thick snowpack.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 19th, 2022 4:00PM
