Avalanche Forecast

Issued: Jan 24th, 2016 8:09AM

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

bcorrigan, Avalanche Canada

Kootenay Boundary.

Wind and storm slabs are still touchy. Use caution venturing into new terrain, especially around treeline.A Special Public Avalanche Warning is in effect for this region.

Summary

Confidence

Moderate - Due to the number and quality of field observations

Weather Forecast

The southern interior will be under the influence of a weak high pressure system for the forecast period. Partly cloudy skies with some sunny periods and freezing levels at valley bottom overnight, then rising to around 1000 metres during the day.The next Pacific frontal system will move into the area late Tuesday with freezing level forecast to rise above 2000 metres.

Avalanche Summary

Numerous reports from across the forecast region yesterday of skier accidental, skier remote, skier controlled, explosives testing and natural avalanches up to size 2.5. In some cases, avalanches were triggered within the storm snow and then stepped down to the early January surface hoar layer. Storm and wind slabs will take time to settle and bond. Recent loading has added mass and sensitivity to the deeper early January persistent weak layer. Until the snowpack has time to adjust to the new load, avalanches on this interface will be large and destructive.

Snowpack Summary

Recent snowfall combined with strong ridge top winds formed storm slabs at all elevations these past few days. In some areas dense snow now overlies colder, less-dense snow deposited earlier in the storm. Rece4nt reports indicate this is settling out, improving the skiing dramatically. On solar aspects, the storm snow is resting on a crust with facets around 80 cm below the surface. These facets may be the remnants of a surface hoar layer formed at the beginning of January. Recent testing has shown this facet layer to be reactive, especially in places with no previous skier or rider activity. It appears to be most prominent at treeline and below, and on all aspects. A melt freeze crust from December buried anywhere from 80 to 130cm across the region is still prominent in the snowpack, but no recent avalanche activity has been reported at this interface, however, it is worth keeping an eye on. With additional loading it may become more problematic. Below this, the snowpack is generally well settled and strong.

Problems

Storm Slabs

Skier triggered avalanches are still happening, use care when venturing into new or big terrain.

Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Be cautious as you transition into wind affected terrain.>Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Persistent Slabs

This layer is still on the radar. An avalanche on this layer could be quite large and destructive.

Use conservative route selection, stick to moderate angled terrain with low consequence.>Be aware of the potential for large avalanches due to the presence of buried surface hoar.>