Avalanche Forecast

Issued: Dec 17th, 2013 8:05AM

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

ali haeri, Parks Canada

Glacier.

A lull between storms, be conservative in your route finding and decision making. Avoid exposing your group to overhead hazard.

Summary

Weather Forecast

We are between storms at the moment but the low off the coast of Alaska will bring in another one this afternoon and into tonight with moderate snow amounts and increasing westerly winds. Temperatures are expected to remain mild until tomorrow when there will be a cooling trend with more clear weather.

Snowpack Summary

55 to 60cm of storm snow sits over a variety of surfaces from December 8th like surface hoar lower down, facets and variable wind slabs at higher elevations. The mid and lower snow packs are faceted but have not been observed to have the typical weakness associated with this.

Avalanche Summary

Yesterday, widespread natural cycle producing numerous avalanches to size 3.5 in the highway corridor and in the backcountry. Big avalanches in Connaught Creek were reported; Grizzly slide path, frequent flyer, and paths from Cheops are ran large. Artillery control in the highway corridor yesterday produced many avalanches to size 3.5.

Confidence

Problems

Storm Slabs

55-60cm of storm snow in the past week with mild temperatures have created ideal slab conditions.

Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 4

Wind Slabs

We have had strong winds during yesterdays storm leaving us with wind slabs at higher elevations.

Be cautious as you transition into wind affected terrain.Avoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 4

Persistent Slabs

Buried surface hoar down between 60-80cm with a recent significant snow load should remain a concern for rider triggering.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 4

Valid until: Dec 18th, 2013 8:00AM