Avalanche Forecast

Issued: Nov 21st, 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.

esharp, Avalanche Canada

South Columbia.

Given the very limited information on hand for this bulletin, I would tread cautiously this weekend and take the time to gather snowpack information as I go. As always, we would love for you to submit any observations from your day to the MIN

Summary

Confidence

Good - Due to the number and quality of field observations

Weather Forecast

High pressure will persist over the region through Sunday before an advancing cold front the North brings moderate snowfall Monday and Tuesday. Sunday: Mainly clear, freezing levels rising up to 1100m with a temperature inversion extending to 2000m, light precipitation starting late in the day. Monday: 5 to15 cm of snow, southwesterly wind, a high of -10C in the alpine. Tuesday: 5 to 10 cm of snow, northerly wind, a high of -15C in the alpine.

Avalanche Summary

I'm working with limited observations but there haven't been any reports of avalanche activity. However, the avalanche cycle that occurred during and immediately after the storm earlier in the week produced some large deep avalanches.

Snowpack Summary

Up to 50cm of low density snow fell in the storm earlier this week. Over the last couple of days moderate westerly winds are likely to have moved this around and formed pockets of wind slab on east and northeast aspects. Below this were dealing with a complex snowpack. A couple of layers of surface hoar were formed earlier in the month. 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. Remember that its still a young snowpack. Rocks and stumps may be lurking unseen just below the surface. Ride with care!

Problems

Wind Slabs

Westerly wind will have redistributed the low density storm snow from earlier in the week, forming soft windslabs. I suspect that the snow in lee features will be quite reactive. Look for shooting cracks as a sign you are entering a wind loaded area.

Be careful with wind loaded pockets>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

A variety of buried persistent weak layers have been reported from across the region including surface hoar, crusts and facets. Although it is starting to look like winter at upper elevations we're still dealing with a young snowpack.

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 22nd, 2015 2:00PM