Avalanche Forecast

Issued: Nov 25th, 2013 8:24AM

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

Avalanche Canada rbuhler, Avalanche Canada

This bulletin was created using very limited field data. Significant variation in snowpack structure is likely to exist across the region. If you are out in the mountains, please send your observations to forecaster@avalanche.ca

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

A ridge of high pressure will continue to dominate Tuesday and Wednesday resulting in dry conditions, light alpine winds, and mostly sunny skies. The ridge will weaken on Thursday resulting in increased cloud cover and alpine wind. A temperature inversion currently exists over most of the Kootenay-Boundary region with a layer of warm air sitting at mountain-top elevation. This inversion should break down on Thursday.

Avalanche Summary

We have received limited reports of pin-wheeling and small loose snow avalanches releasing on steep, sunny aspects during afternoon warming. If you've been out in the mountains and observed recent avalanche activity, please report it to forecaster@avalanche.ca

Snowpack Summary

Snow depth is typically 80-110cm at treeline although observations are limited and this amount may vary across the region. Roughly 60 to 70cm of well settled storm snow is now sitting on the October crust located just above the ground. Little is known about the reactivity of this crust; however, limited reports suggest that the crust interface is well bondedThe current temperature inversion is causing the snow surface to melt in the alpine. Sun exposed slopes are undergoing daily melt-freeze cycles. A surface crust is also being reported below 1700m. Large SH is forming on all aspects but is melting on south aspects during the daytime warming. If you are traveling in the mountains, now is a good time to make note of these surface conditions which may become persistent weak layers once buried by new snow.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Limited reports suggest it has become very difficult to trigger a persistent slab on the October crust. However, if an avalanche is triggered, it has the potential to be large and destructive.
Dig down to find and test weak layers before committing to a line.>Caution around convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 5

Valid until: Nov 26th, 2013 2:00PM

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