Avalanche Forecast
Issued: Dec 25th, 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
What more could we want than a beautiful, sunny boxing day with chilly temps to help keep the new snow dry and fluffy? For you to share your day with us on the Mountain Information Network, of course!
Summary
Confidence
Moderate - Confidence is due to a stable weather pattern with little change expected.
Weather Forecast
Saturday night: Clearing. No new snow. Light variable wind. Treeline high temperatures near -12 C.
Sunday: A mix of sun and cloud. Light northwest wind. Treeline temperatures dropping to -17 C.
Monday: Increasing cloud. Wind increasing to strong northwest. Treeline temperatures around -13 C.
Tuesday: A mix of sun and cloud. Strong northwest wind. Treeline temperatures around -13 C.
Avalanche Summary
Avalanche activity on Thursday and Friday was predominantly small loose dry, size 1-1.5, observed out of steep terrain at treeline. On Thursday, evidence of natural storm slab avalanches size 2-2.5 were observed out of north facing alpine terrain.
Snowpack Summary
Recent low density snow has seen some redistribution at upper elevations, forming deep, soft deposits in leeward terrain features. 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
- Make observations and assess conditions continually as you travel.
- 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 may remain reactive to human triggers 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. We haven't had any new data on this layer for a few days so if you have any observations, please share with us on the Mountain Information Network!
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 26th, 2021 4:00PM
