Avalanche Forecast

Issued: Dec 8th, 2017 4:00PM

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

Garth Lemke, Parks Canada

Jasper.

Good skiing can be found on north aspects. Solar triggering is possible on steep Alpine south aspects. Ice climbers need to be vigilant.

Summary

Weather Forecast

Saturday will be sun and cloud, no new snow, freezing level 1900m, and light West wind. Sunday will be much the same except for 1600m freezing level and weak temperature inversion. Monday will be similar but warmer with 3300m freezing level.

Snowpack Summary

There is a well settled snowpack in most locations. A 30 - 70 cm thick slab overlies a crust and bonding appears to be strengthening at this interface. The Halloween Oct 31 crust sits near the bottom of the snowpack from treeline to 2700 m.

Avalanche Summary

No patrol occurred on Friday and nothing new was reported. A helicopter flight on Thursday observed numerous dry loose avalanches, size 1-2, along the Icefields Parkway and Maligne Lake Road on steep solar aspects, running to treeline. One size 3 slab avalanche was noted on a steep South facing slope that ran on the Halloween Crust to treeline.

Confidence

The weather pattern is stable on Saturday

Problems

Loose Dry

Solar triggering of loose avalanches is occurring in steep terrain. The entraining snow has enough volume to knock ice climbers off or bury you in a terrain trap. Reactivity increases with afternoon sun.

Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

Solar triggering is possible on steep south facing slopes creating large avalanches.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Dec 9th, 2017 4:00PM