Avalanche Forecast

Issued: Jan 4th, 2014 4:00PM

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

steve blagbrough, Parks Canada

Jasper.

Moderate to strong winds are starting to redistribute the recent storm snow into sheltered areas which could in turn over load the basal weak layer.

Summary

Weather Forecast

Very cold temperatures tonight will be followed by a return to milder temps next week. Moderate to strong ridge top winds will lead to a redistribution of the recent storm snow onto sheltered aspects.

Snowpack Summary

Up to 30cm of new storm snow overlies existing wind slabs which in places has a very weak faceted basal layer. Below tree line the snow pack has very little support except in isolated open areas where wind slabs may exist.

Avalanche Summary

Road patrols in the South end of the forecast area observed one size 3 slab that failed on the basal facets and a size 2.5 storm slab at TL. Numerous smaller slabs from cross loaded features and sloughing was also observed.

Confidence

Problems

Deep Persistent Slabs

Triggering this layer from a shallow area is possible and would have high consequences in terrain features of any size.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.Avoid convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 4

Wind Slabs

Wind slab layers at the top of the snowpack can be triggered and may step down to the deeper instability at the bottom of the snow pack.

Avoid ice climbs that are in terrain traps below large start zones.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Valid until: Jan 5th, 2014 4:00PM