Avalanche Forecast

Issued: Mar 4th, 2017 4:00PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Storm Slabs, Loose Dry and Deep Persistent Slabs.

rupert wedgwood, Parks Canada

Jasper.

The Icefields Parkway North of Saskatchewan Crossing and the Maligne Lake road remain closed until avalanche control can taken place on Sunday. Many large avalanches are running and will likely continue to do so throughout the weekend.

Summary

Weather Forecast

Colder temperatures over the next 24 hrs with overnight lows of -15 at treeline. Highs on Sunday will be close to -10 with light to moderate southerly winds and snow flurries at higher elevations to 10cm. No significant snowfall forecast next week with cool temperatures and a moderate westerly flow.

Snowpack Summary

Up to 45cm of storm snow has been received across the forecast area during the past 36 hours. Under the influence of light to moderate southerly winds a soft slab is forming at treeline and above. The mid and lower snowpack is unstable, the base of which is weak depth hoar crystals and a rain crust, dating from November.

Avalanche Summary

Avalanche control was stalled due to poor flying conditions. Field teams were able to determine that there was widespread avalanche activity up to size 3. Although the visibility was poor these events seem most prevalent in the alpine from the new storm slab which, as predicted, is stepping down to basal weakness resulting in deep releases.

Confidence

Problems

Storm Slabs

45cm of storm snow is forming a soft slab at treeline and above. It will remain very reactive to triggering for the next 24 hours. Where stronger winds in the alpine have transported the snow it may be up to 60cm thick.

Conditions are Extreme. Avoid backcountry: stick to ski resorts or trackset cross country trails.Avoid all avalanche terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

2 - 3

Loose Dry

Loose snow avalanche can be expected from all steep rocky features which may then channel into gulleys or trigger deeper avalanches from open slopes.

Be cautious of sluffing in steep terrain.Avoid travelling under cliffs that are exposed to sluffing from above.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 3

Deep Persistent Slabs

Increased loading above this layer from the recent storm snow has produced number releases up to size 3. These are mostly from the alpine and treeline elevations and are running down to the valley bottoms.

If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

2 - 3

Valid until: Mar 5th, 2017 4:00PM