Avalanche Forecast

Issued: Nov 21st, 2015 7:54AM

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

Avalanche Canada esharp, Avalanche Canada

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

Fair - Due to the number and quality of field observations

Weather Forecast

High pressure will persist over the region through Sunday before an advancing cold from the North brings light snowfall Monday and Tuesday. Sunday: Mainly clear, a temperature inversion may exist in the morning but freezing levels are forecast to fall back to the valley floor throughout the day. Monday: 2 to10 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

Im working with limited observations but there havent been any recent reports of avalanche activity. However, the avalanche cycle that occurred during and immediately after the storm earlier in the week produced some large avalanches. Last weekend there was a report submitted to the Mountain Information Network of rider a triggered avalanche that released on basal facets at treeline in the Dogtooth range near Golden.

Snowpack Summary

Up to 50cm of low density snow fell in the storm earlier this week. A MIN report from the south of the region suggest that some of this fell as rain forming a crust up to 1900m near Kimberley. Moderate westerly winds are likely to have formed pockets of windslab on east and northeast aspects. Below this we're 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 50 to 100 cm. Depending on where you dig, you might also find a couple of crusts. It would be wise to test these layers before committing to a slope. Facets are likely to be found just above the ground at higher elevations in the alpine. Remember that it's still a thin snowpack. Rocks and stumps may be lurking unseen just below the surface. Ride with care!

Problems

Wind Slabs

An icon showing 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, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Persistent Slabs

An icon showing 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.
Early season hazards such as rocks, trees and stumps are lurking on or just under the surface>Now is a good time to dig a snow profile (or two) and figure out how the snowpack changes with aspect and elevation.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

Valid until: Nov 22nd, 2015 2:00PM