Avalanche Forecast

Issued: Jan 3rd, 2018 4:18PM

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

pgoddard, Avalanche Canada

Cariboos.

Loose wet avalanches are likely in steep, rocky, sunny terrain. Warming could also wake up more deeply buried weak layers.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Thursday: Mainly cloudy, with flurries possible. A layer of warm air is expected between 2000-2500m, while it remains cold in the valleys. Light variable winds.Friday: Cloudy with flurries. Warm conditions may persist above 1800m in some areas. Moderate southwesterly winds.Saturday: Light snow (5-10 cm). Light to moderate south-westerly winds.More details can be found on the Mountain Weather Forecast.

Avalanche Summary

Recent reports are of a few naturally-triggered avalanches to size 1.5 running in steep terrain. These have included solar-triggered loose wet avalanches and wind slabs, depending on slope aspect. Slab avalanches are becoming more likely as the upper snowpack starts to settle with warm temperatures.

Snowpack Summary

Warming, particularly at treeline elevations, could wake up persistent weak layers. The upper snowpack consists of dry snow (becoming moist on sunny slopes) overlying a couple of layers of buried surface hoar (feathery frost crystals). The deeper of these, buried mid-December and down 30-60 cm, is the main concern. A little warming, precipitation and/or wind-loading could be all that is needed to turn powder into a slab above this touchy interface. The buried surface hoar is most prevalent at and below treeline.Deeper in the snowpack (about 70-100 cm down), a rain crust from November remains in the back of our minds, but it is considered dormant for now. If you have any recent observations, please share them through the Mountain Information Network.

Problems

Persistent Slabs

With warming temperatures, recent storm snow is expected to settle into a slab over a touchy persistent weak layer.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Use conservative route selection. Choose moderate angled and well supported terrain.Avoid open slopes and convex rolls at treeline where buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

Loose snow avalanches may fail with human or solar triggers at alpine elevations.

Choose routes that are not exposed to avalanches from above.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

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