Avalanche Forecast

Issued: Mar 5th, 2019 4:50PM

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

kdevine, Avalanche Canada

Cariboos.

Human triggered avalanches remain possible, especially in wind loaded areas. A persistent slab problem at lower elevations still requires careful terrain selection, as the consequences of an avalanche on this layer remain high.

Summary

Confidence

Moderate -

Weather Forecast

TUESDAY NIGHT - Clear periods / east winds 20-35 km/h / alpine low temperature near -10WEDNESDAY - Cloudy with sunny periods / southeast winds 20-40 km/h / alpine high temperature near -5THURSDAY - Flurries, 5 cm / southwest winds 10-20 km/h / alpine high temperature near -7FRIDAY - Cloudy with scattered flurries / west winds, 15-25 km/h / alpine high temperature near -10

Avalanche Summary

No new avalanches have been reported in the region over the past few days, but observations in neighbouring regions have shown regular, generally small (size 1) wind slabs reacting to skier traffic and ski cutting at higher elevations. Avalanche activity on the mid January persistent weak layer has tapered off, however test results still suggest that this layer could be triggered by humans in specific locations. When persistent weak layers stop producing regular avalanches, they can become very difficult to manage. This weak layer has become a low likelihood/high consequence avalanche problem. Check out a recent MIN report from Allen Creek here that illustrates this.

Snowpack Summary

The upper snowpack at higher elevations is a mix of wind-affected snow and wind slabs on all aspects, as well as a crust on sun exposed slopes. The wind slabs are sitting on facets (sugary snow), and may continue to be reactive.In more sheltered areas at lower elevations, a weak layer buried in mid January can be found approximately 50-60 cm deep. This layer consists of surface hoar (feathery crystals) and facets, and may be combined with a crust on south facing slopes. This layer has been most reactive at treeline and below treeline. The lower snowpack is generally considered to be strong, except for shallow, rocky areas where cold temperatures continue to facet (weaken) the snowpack.

Problems

Wind Slabs

Wind slabs can be found on all aspects and may continue to be reactive due to the weak, faceted snow they sit above.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Steep and rocky terrain are likely places to trigger buried wind slabs.Increase caution around wind loaded pockets near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Persistent Slabs

50-60 cm of snow sits above a persistent weak layer of surface hoar buried in mid-January. This layer has evolved into a lower likelihood/high consequence avalanche problem.

Exercise increased caution around low elevation cut-blocks where this layer has been well preserved.Maintain diligent group management around open and/or sparsely treed slopes at treeline and below.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Unlikely

Expected Size

1 - 2

Valid until: Mar 6th, 2019 2:00PM