Avalanche Forecast

Issued: Nov 22nd, 2015 7:57AM

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

Avalanche Canada esharp, Avalanche Canada

There is quite a bit of variability in the snowpack structure across the region with different weak layers existing in different areas.  Take the time to look in the snow and submit any observations from your day riding to the MIN.

Summary

Confidence

Fair - Due to the number and quality of field observations

Weather Forecast

A cold front descending from the North is going to bring between 10 and 20 cm of snow over the next couple of days with the greatest accumulations expected for the mountains around Revelstoke. By Wednesday, a high pressure system will settle over BC bringing several days of chilly but stable weather. Winds will be light from the south on Monday, becoming northerly on Tuesday and Wednesday.

Avalanche Summary

There was apparently lots of traffic in the backcountry over the weekend without any reports of new avalanche activity. However, the presence of wind slabs and the lingering basal weakness on north to east facing terrain in the alpine give me concern that smaller wind slab avalanches could possibly step down to deeper layers.

Snowpack Summary

It sounds like folks found excellent "bottomless" riding conditions over the weekend. The forecast snowfall is expected to bond well to the 50 to 80cm of low density snow that fell last week. At tree-line elevations and above, the new snow may hide pockets of windslab on east and northeast aspects. In the south of the region, this new snow could also hide a surface crust that I suspect extends up into the alpine. Below this, were dealing with a varied snowpack. A couple of layers of surface hoar formed earlier in the month. Where they exist, they are likely to be found down 65 to 140 cm below the surface. Depending on where you dig, you might also find one or more buried crusts. It would be wise to test these layers before committing to a slope. Facets can be found near the ground at higher elevations in the alpine, especially on northerly aspects. Remember that it's still a young snowpack. Rocks and stumps may be lurking unseen just below the surface. Ride with care!

Problems

Wind Slabs

An icon showing Wind Slabs
New snow may cover fresh wind slabs. I suspect that the snow in north to east facing lee features will still be quite reactive. Look for shooting cracks as a sign you are entering a previously wind loaded area.
Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

An icon showing Persistent Slabs
We're still dealing with a highly variable early season snowpack and several persistent weak layers have been reported from across the region including surface hoar crusts and facets. Smaller surface avalanches could possibly step down.
Now is a good time to dig a snow profile (or two) and figure out how the snowpack changes with aspect and elevation.>Early season hazards such as rocks, trees and stumps are lurking on or just under the surface>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

Valid until: Nov 23rd, 2015 2:00PM