Avalanche Forecast

Issued: Dec 21st, 2016 4:45PM

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

mbender, Avalanche Canada

Kootenay Boundary.

As this past week's storm snow continues to settle it will still be important to evaluate the bond between the old snow surface and the new snow. There is still potential for a week sliding layer in isolated sheltered areas.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

Thursday: Mainly cloudy / Moderate southwest wind / Alpine temperature -6Friday: Flurries, accumulation 5-10cm / Light east wind / Alpine temperature -5Saturday: Flurries, accumulation 5-10cm/ Light east wind / Alpine temperature -8

Avalanche Summary

Recent reports indicate a few avalanches triggered from explosives control running wind slabs on the storm/old snow interface to size 2 at tree line and above.

Snowpack Summary

20-40 cm of new snow has buried previously formed windslabs, facets and surface hoar. There is a bit of uncertainty regarding how the new snow is bonding to old surfaces which formed during last week's cold clear period. Moderate to strong winds have loaded leeward features with new touchy wind slabs. A widespread crust that was buried in November is typically down 80-100cm. Recent tests show variable results with this persistent weakness. Some show results as hard and resistant and other show it may have the propensity to propagate large avalanches if triggered from thin rocky areas.

Problems

Wind Slabs

Moderate to strong southwest winds continue to create slabs in the lee of terrain features

Be cautious as you transition into wind affected terrain.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Dig down to find and test weak layers before committing to a line.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Dec 22nd, 2016 2:00PM