Avalanche Forecast

Issued: Nov 28th, 2017 3:46PM

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

Avalanche Canada mgrist, Avalanche Canada

Be aware of areas that have seen rapid loading due to new snow and strong winds, and avoid exposure to avalanche terrain during these periods.

Summary

Confidence

Low - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

We're looking at a lull in the active weather pattern from Wednesday onwards.WEDNESDAY: Cloudy. Moderate westerly ridgetop winds. Freezing level around 1200 m.THURSDAY: Cloudy with sunny breaks during the day and isolated flurries. Moderate southwesterly ridgetop winds. Freezing level around 1100 m. FRIDAY: Some isolated flurries (5 cm possible). Moderate south west ridgetop winds. Freezing level around 1000 m.

Avalanche Summary

On Monday, a Size 2 wind slab was reported with explosives control work in the north of the region on a northerly aspect near 2300m. Natural avalanche activity is expected on Tuesday with another pulse of snow. We currently have very limited observations in this region. Please submit your observations to the Mountain Information Network (MIN).

Snowpack Summary

Last week, the November 23rd crust formed as temperatures cooled and the rain-soaked snow surface froze. Since then, 15-40cm of snow has fallen at treeline and above with moderate to strong south (west) winds, creating wind slabs sitting on a crust. The depth of the snowpack varies greatly with elevation. Recent reports suggest the average depth is 150+cm in the alpine, 100-150cm at treeline, and decreasing rapidly below treeline where the primary hazards are rocks, stumps, and open creeks. Two other layers have been reported in the snowpack: 1) The Halloween crust (down 100cm at treeline elevations) and 2) The November 10th surface hoar / facets (down 80cm at treeline elevations). We have very little information on how reactive these layers are, in fact, we currently have very limited snowpack observations within this entire region and it is critical to supplement this information with your own observations.

Problems

Storm Slabs

An icon showing Storm Slabs
A natural avalanche cycle is expected on Tuesday into Wednesday with the incoming snow. Careful assessment of the snowpack is essential - be aware of conditions changing quickly with elevation and aspect.
Avoid exposure to avalanche terrain during periods of rapid loading by snow or wind.Watch for signs of instability such as whumpfing, cracking or recent natural avalanches.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Nov 29th, 2017 2:00PM