Avalanche Forecast

Issued: Dec 24th, 2015 8:59AM

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

ghelgeson, Avalanche Canada

Kootenay Boundary.

Storm slabs should be getting less and less sensitize to human triggering, but you need to exercise due diligence and carefully investigate the new/old snow interface before committing to the bigger more complex lines.

Summary

Confidence

Moderate

Weather Forecast

After a very active pattern that has delivered storm after storm, the pendulum is swinging to the opposite end of the spectrum. Wind is the big story for the forecast period, but we are not expecting any new snow in the Kootenays until at least the New Year. CHRISTMAS: No snow expected, freezing level at valley bottom, light N/NW winds. BOXING DAY: No new snow, freezing level at valley bottom, light S/SW winds. SUNDAY: No significant precipitation, freezing level at valley bottom, light SW winds at treeline, strong SW winds at ridgetop.

Avalanche Summary

Recent avalanche activity has been limited to small loose snow avalanches on steep features and small wind slabs.

Snowpack Summary

30 to 60cm of storm snow is slowly settling into a very soft slab that rests on the mid-December weak layer. This layer is just a crust in most places, but in Kootenay Pass there is a surface hoar interface on or just above this crust that is most prevalent between 1800 and 2000m. At treeline the early December crust is down around 50 to 100cm, and it's thick and supportive nature is likely capping any deeper weaknesses in most places. However, recent observations from the Nelson area indicate that there are facets on this crust, so it's an interface to watch as we move into the New Year. The lower snowpack is thought to be well settled.

Problems

Storm Slabs

There is a bit of variability with regard to the upper snowpack throughout the region right now, so carefully evaluate local conditions before committing to the bigger lines.

On steep slopes, pull over periodically or cut into a new line to manage sluffing.>Exercise extra caution around recently wind loaded features and use ridges/ribs to sneak around these problem areas.>Be aware of pockets of buried surface hoar at treeline, especially around Kootenay Pass. There, open slopes and convex rolls at treeline are potential problem areas.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 25th, 2015 2:00PM