Avalanche Forecast

Issued: Dec 3rd, 2018 4:58PM

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

Avalanche Canada ghelgeson, Avalanche Canada

The snowpack is thin and relatively weak. Human triggerable avalanches remain possible at and above treeline and are especially problematic immediately lee of ridgecrest in steep unsupported terrain.

Summary

Confidence

Low - Due to the number of field observations

Weather Forecast

The high amplitude ridge sitting off the BC Coast is expected to deflect any potential storm systems away from the province this week. The forecast period is marked by cooler temps, clear skies and no significant precipitation with no change expected for the foreseeable future.MONDAY NIGHT: Freezing level at valley bottom, light southerly wind at most elevations, moderate northwest wind at ridgetop, no significant precipitation expected. TUESDAY: Scattered cloud cover, freezing level at valley bottom, light southerly wind at most elevations, moderate northwest wind at ridgetop building to strong northwest wind at ridgetop in the late afternoon, no significant precipitation expected. WEDNESDAY: A few clouds, freezing level at valley bottom, light variable wind, no significant precipitation expected. THURSDAY: Clear sky, freezing level at valley bottom, light variable wind, no significant precipitation expected.

Avalanche Summary

On Sunday, a human triggered avalanche size 1.5 was reported. This ran on a northwest aspect at 2300 m. The crown was 15 cm, 20 m wide and ran 300 m. Check out the initial report here. Explosive control also triggered a few storm slabs up to size 2 from northeasterly aspects 1800-2000 m. If you're in the backcountry and have observations to share, please post to the Mountain Information Network.

Snowpack Summary

Up to 55 cm of recent snow sits on a combination of crust and surface hoar. The crust is most prevalent at and above treeline and is likely most problematic on north facing features, especially those that are large and planar in nature.The surface hoar is tricky to pin down because it is quite spotty in distribution, but it appears to be most prevalent on sheltered slopes at and above treeline. At the bottom of the snowpack lies another crust with weak sugary facets around it.  There is a great MIN Report here that provides a good visual representation of the current snowpack.At treeline the average snowpack depth is 80 cm, with only thin coverage at lower elevation.

Problems

Persistent Slabs

An icon showing Persistent Slabs
55 cm of recent storm snow is consolidating into a slab above buried weak layers. Human triggering likely remains possible, especially in steep unsupported terrain.
Avoid shallow, rocky areas where the snowpack transitions from thick to thin.Back off if you encounter signs of instability like whumphing, shooting cracks or recent avalanches.Be aware of the potential for large avalanches due to the presence of a persistent slab.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 4th, 2018 2:00PM

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