Avalanche Forecast
Issued: Dec 24th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
ahanna,
Avalanche Canada
Fantastic snow and safest avalanche conditions can be found in low elevation, wind-sheltered terrain. We have uncertainty around a potential weak layer sitting beneath recent snow at upper elevations so if you plan to venture up high, make observations and assess as you go.
Summary
Confidence
Moderate - Uncertainty is due to limitations in the field data.
Weather Forecast
Friday night: A trace of new snow. Light to moderate northwest wind shifting southwest. Freezing level dropping to sea level.
Saturday: Mainly cloudy, scattered flurries bringing 2-8 cm of snow. Moderate southwest winds. Treeline high temperatures near -12 C.
Sunday: A mix of sun and cloud. Light northeast wind. Treeline temperatures dropping to -17 C.
Monday: A mix of sun and cloud. Wind increasing to strong northwest. Treeline temperatures around -13 C.
Avalanche Summary
On Thursday, evidence of natural storm slab avalanches size 2-2.5 were observed out of north facing alpine terrain and several natural loose dry avalanches size 1-1.5 were observed in steep treeline terrain.
Snowpack Summary
Recent low density snow has likely been redistributed into atypical cross-loading or reverse-loading patterns by easterly wind at upper elevations. 15-30 cm now sits over a freezing rain crust below 1500 m and above this elevation it may rest on a layer of large surface hoar crystals. Our field team reported easy shears on this layer in their MIN report from during the storm on Wednesday. You can see photos of the surface hoar prior to being buried by the storm in these MIN reports from Elk Mountain on Monday and Mt Kitchener on Tuesday.
A crust-facet sandwich formed in early December can now be found a meter deep. These layers show limited reactivity and are well bridged by strong snowpack layers above them. Below, the snowpack is generally well-settled.
Terrain and Travel
- Sheltered low elevation terrain will likely offer the best and safest riding today.
- Be alert to conditions that change with elevation.
- Closely monitor how the new snow is bonding to the crust.
- Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
Problems
Storm Slabs
Storm slabs are most likely to remain reactive at upper elevations where the recent snow has been wind loaded over a weak layer of preserved surface hoar or where it sits over a freezing rain crust below 1500 m.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 25th, 2021 4:00PM
