Avalanche Forecast

Issued: Jan 13th, 2014 5:24PM

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

steve blagbrough, Parks Canada

Jasper.

The natural cycle is tapering off now but the snowpack is proving very touchy to human triggering.

Summary

Weather Forecast

Winds will continue to redistribute snow in the alpine and treeline elevations. Light snow will turn to rain at lower elevations as we go into a warming cycle.

Snowpack Summary

Up to 70cm of storm snow has been redistributed by moderate to strong SW winds creating wind slab over a strong mid-pack in lee features on top of a weak basal facets layer at the ground.

Avalanche Summary

A field team in the Maligne Lake area remotely triggered a size 2.5 from a distance of 20m. In the Icefields area a group remotely triggered a size 1.5. Both avalanches were on open slopes at treeline and ran on the basal facet layer. Whumphing and shooting cracks were observed in both locations. Some natural activity to size 2.5 observed.

Confidence

Freezing levels are uncertain on Wednesday

Problems

Deep Persistent Slabs

This layer is proving very susceptible to human triggering as evidenced by the two remotely triggered slides today. Extensive whumphing and cracking experienced particularly at treeline elevations.

Be aware of thin areas that may propogate to deeper instabilites.Avoid steep, open slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3

Storm Slabs

70cm of storm snow has fallen in the past 72hrs and has been redistributed by moderate to strong SW winds onto sheltered slopes in the alpine and treeline.

Avoid avalanche terrain during periods of heavy loading from new snow and wind.The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

A failure in this layer is likely to trigger the weak basal facet layer below.

Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.Avoid ice climbs that are in terrain traps below large start zones.

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 14th, 2014 4:00PM