Avalanche Forecast
Issued: Jan 19th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Persistent Slabs and Deep Persistent Slabs.
snow safety,
Parks Canada
The continued warming trend and strong winds will likely bring an increase in avalanche activity over the next few days. Conservative terrain choices will be your best defence.
Summary
Weather Forecast
Temperatures will continue to warm into the start of the week with Tuesday being the peak of the warming trend. This warm air mass will be associated with strong South Westerly winds creating the perfect recipe for new wind slab development. Light precipe is forecasted for later in the week.
Snowpack Summary
 Warming temperatures and moderate to strong Southerly winds continue to build wind slabs in the alpine and open areas at tree line. There is up to 60 cm above the Dec 31 layer of facets, surface hoar and sun crust. Concern remains for the weak layers of facets and depth hoar near the base of the snowpack.
Avalanche Summary
Direct observations and second hand reports of avalanches in the forecast region continue to come in. One avalanche of note was a skier triggered size 3 200m wide on Lipalian (near Lake Louise). The slab step down through multiple layers eventually releasing the basel instability, skier had a close interaction but was able to avoid involvement.
Confidence
Problems
Wind Slabs
Reactive wind slabs reported over the last 2 days which will likely continue with the warming temperatures and strong winds.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Use caution in lee areas. Recent wind loading have created wind slabs.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
This layer may present as surface hoar, facets or sun crust. It is buried 40-80cm throughout the region and produces variable results depending on location and what crystal form is present. There is high uncertainty as to how reactive this layer is.
- If triggered the persistent slab may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Were beginning to receive reports of increased avalanche activity from the problem (see forecast details for more info) Conservative terrain choice is your best defence.
- Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.
- Avoid shallow snowpack areas where triggering is more likely.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 20th, 2020 4:00PM
