Avalanche Forecast
Issued: Mar 11th, 2020 8:00AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
chris gooliaff,
Parks Canada
Presently we are in a natural avalanche cycle. This will taper off throughout the day but the snowpack will take some time to adjust to the new load.
Expect storm slabs to be reactive to human loads.
Summary
Weather Forecast
Mixed sun and cloud today, followed by flurries Thurs/Fri and cold air by Friday night.
Today: Mix of sun and cloud, isolated flurries (trace amounts), alpine high -10*C, mod W winds
Thurs: Cloudy, scattered flurries, 5cm, alpine high -13*C, light W winds
Fri: Cloudy with gradual clearing, trace precip, alpine high -14*C dropping to -25*C, mod E winds
Snowpack Summary
25-30cm of snow and mod/strong SW winds last night has created a reactive storm slab. The new snow sits on a thin suncrust on solar aspects and small surface hoar on N'ly aspects. Below this slab, the Feb 22nd persistent weak layer is down 80-120cm, and consists of 3-7mm surface hoar on all aspects up to 2450m, and a crust on solar aspects.
Avalanche Summary
Natural avalanches began running to valley bottom last night up to size 3-3.5 from both N and S aspects. Several were observed crossing the snowsheds under Mt Tupper. Artillery control has also produced numerous sz 3's. We are in the middle of the natural cycle, which will likely subside with cooling temps and a drop in wind speed.
Confidence
Problems
Storm Slabs
25-30cm of new snow with mod/strong winds has created a widespread storm slab. Lee and cross-loaded features at upper elevations will shed this new layer easily. Unsupported slopes/terrain traps below tree-line should be treated with respect today!
- If triggered the storm slabs may step down to deeper layers resulting in large avalanches.
- Avoid steep convexities or areas with a thin or variable snowpack.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
The February 22 Surface Hoar/ sun crust layer is down 90-130cm. It's possibly for skier-triggering in shallower snowpack areas, but otherwise this layer will take a bigger trigger to be activated (ex avalanche in the storm slab).
- Be aware of the potential for wide propagations.
- Avoid steep convexities or areas with a thin or variable snowpack.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 12th, 2020 8:00AM
