Avalanche Forecast

Issued: Nov 23rd, 2015 8:45AM

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

Avalanche Canada ghelgeson, 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

Poor - Due to the number of field observations

Weather Forecast

Total snowfall from this storm should range between 5 and 30cm with the northern portion of the forecast region receiving the most snowfall. Moderate to Strong SW winds are expected to continue through Monday evening. Very cold air descending from the Arctic will lead to clearing skies and cold temperatures for the next few days. For detailed mountain weather information visit avalanche.ca/weather

Avalanche Summary

We're working with limited observations but there haven't been any reports of recent avalanche activity. However, the avalanche cycle that occurred during and immediately after last weeks storm produced some large natural avalanches.

Snowpack Summary

Total snowfall from Monday's storm should be between 5 and 30 cm which is coming to rest on a wide variety of old surfaces including crust, surface hoar and old settled snow.  Moderate to strong SW winds likely continue to form pockets of wind slab on east and northeast aspects. A couple of persistent weak layers exist in our early season snowpack.  Where they exist, they are likely to be found buried down 65 to 120 cm. Depending on where you dig, you might also find one or more crusts. It would be wise to test these layers before committing to a slope. Facets can be found at the bottom of the snowpack at higher elevations in the alpine, especially on northerly aspects. Rocks and stumps may be lurking unseen just below the surface.

Problems

Storm Slabs

An icon showing Storm Slabs
New snow and wind have likely combined to form fresh wind slabs in wind exposed terrain at and above treeline. These wind slabs could be quite reactive, especially near ridge crest.
Use caution in lee areas in the alpine. Recent wind loading has created wind slabs.>Avoid freshly wind loaded features.>Be cautious of sluffing, especially in terrain traps like creek bottoms which still feature running water.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

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.
Now is a good time to dig a snow profile (or two) and figure out how the snowpack changes with aspect and elevation.>Be aware of thin areas that may propogate to deeper instabilites.>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 - 5

Valid until: Nov 24th, 2015 2:00PM