Avalanche Forecast

Issued: Feb 11th, 2015 8:00AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Persistent Slabs, Storm Slabs and Loose Wet.

Parks Canada danyelle magnan, Parks Canada

Conditions will remain tricky until temperatures cool. Avalanche activity continues to occur sporadically during brief periods of precipitation or sun. Minimize exposure to overhead avalanche terrain and slopes threatened by cornices.

Summary

Weather Forecast

Wed and Thurs will be mainly cloudy with flurries. Freezing levels remain around 1800m with alpine temps steady at -1'C. On Friday, freezing levels rise to 2800m with an alpine high of +2'C. Wet flurries at ridgetop and light rain at lower elevations are forecast, although amounts are light.  Throughout the forecast moderate SW winds are expected.

Snowpack Summary

Up to 20cm of snow has buried moist snow from the weekends rain. 140cm have fallen since Feb 1 and settled to ~1m of settled storm snow over the Jan 30 layer. This layer formed a crust to 2200m with spotty surface hoar distribution. Jan 15 surface hoar layer is down 100-150cm and continues to be reactive in tests.

Avalanche Summary

Avalanche activity continues during periods of precipitation, with large avalanches running into fans.  Reports from skiers in the region are of touchy conditions, with remote triggering of slabs up to 1m deep and wide propagations. Below 1500m moist snow is touchy and easily triggered by skiers, especially on steep gully like features.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Persistent Slabs

An icon showing Persistent Slabs
Persistent weak layers within the top 150cm of the snowpack should not be forgotten. They continue to be reactive, and produce very large avalanches. Smaller avalanches or cornice failures may step down and propagate on these deep instabilities.
If triggered the storm slabs may step down to deeper layers resulting in large avalanches.Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 4

Storm Slabs

An icon showing Storm Slabs
A warm, wet and windy storm over the weekend created a storm slab that is up to 1m deep. On lee slopes, wind loading may have made this slab much deeper and more reactive. Tests indicate that the slab is stabilizing, but triggering is still possible.
Use conservative route selection, choose moderate angled and supported terrain with low consequence.The new snow will requires several days to settle and stabilize.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Loose Wet

An icon showing Loose Wet
Small avalanches are easily triggered by skiers below ~1500m where wet snow runs easily on the crust below. Once moving they gain mass until the slope lessens. Although small these wet slides could easily hurt a skier, or bury them in a terrain trap.
Be very cautious with gully features.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 12th, 2015 8:00AM