Avalanche Forecast

Issued: Jan 19th, 2014 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Deep Persistent Slabs and Wind Slabs.

garth lemke, Parks Canada

Jasper.

Still not the time to ski big lines despite Moderate rating. Lots of variability across the landscape with a lurking basal weakness. Shallow locations are the likely trigger spots. Human triggered avalanches are possible on specific terrain features.

Summary

Weather Forecast

Next three days will be mainly dry with scattered clouds and sun. Temperatures will range from -2 to -11 with light West winds.

Snowpack Summary

Below treeline snowpack is 85cm of low density snow with a 20cm stiffer midpack over weak basal facets. It remains the weakest of our elevation bands as not much bridges the basal facets. Whumphs still occurring. Above TL, snowpack ranges from 10cm to 130cm where a thicker midpack bridges the basal facets. Variable thickness windslabs present.

Avalanche Summary

No patrol today. The team was responding to an avalanche accident in Valemount. Thursday's control work on the Icefields Parkway yielded large avalanches to size 3 on all alpine aspects releasing on either the storm snow interface or on basal facets.

Confidence

Problems

Deep Persistent Slabs

The basal facets are weaker below tree line as many whumphs noted. Where the snow is deeper at higher elevations, the mid-pack bridges the weak basal facets; however, snowpack depth varies so much that its hard to inspire confidence in stability.

Be aware of the potential for wide propagations.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Wind Slabs

Wind slabs of variable thickness and hardness dot the landscape. Many windpressed and stripped features will be encountered once you leave the shelter of the trees. Triggering this could dig down to the basal facets increasing the consequence.

Be aware of the potential for wide propagations due to the presence of hard windslabs.Avoid cross loaded features.

Aspects: North, North East, East, South East, South.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Jan 20th, 2014 4:00PM