Avalanche Forecast

Issued: Jan 5th, 2017 5:00PM

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

Avalanche Canada mgrist, Avalanche Canada

Cold north winds have been blowing. Areas with wind slabs (south through northwest aspects) may have elevated danger.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

We're beginning to see a shift from the cold conditions of late with daytime temperatures warming up by 5-10 degrees Celcius. Only some isolated flurries possible until late Sunday when a small amount of light dry snow may fall (10-15 cms).FRIDAY: Up to 5cms light dry snow possible Thursday overnight into Friday. Mainly cloudy Friday with winds light southerly. Alpine temperatures near -14 Celcius. SATURDAY: Sunny breaks with increasing clouds overnight. Slight chance of flurries. Winds light southeasterly. Alpine high temperatures near -12 Celcius; overnight lows to -18.SUNDAY: Cloudy with flurries in the afternoon. Wind light southeasterly. Alpine high temperatures near -12 Celcius; 10-15 cms light dry snow possible overnight.

Avalanche Summary

No new avalanches reported today. Earlier in the week we had reports of several skier-triggered windslabs (Size 1.5-2) in the backcountry near Nelson. Aspects were southwest through north at treeline and in the alpine.

Snowpack Summary

On and near the surface, facets and surface hoar continue to form throughout the region, while some sun crust is found on steep solar (south) aspects. The snow from last week (30-60 cm) has been exposed to east through northerly winds during this cold clear period. In many areas "reverse loading" occurred, causing windslabs to form and giving sudden planar results in snowpack tests. The most recent snow sits over a weak layer buried on Boxing Day that was initially reactive but now appears to have gained strength. Slightly lower in the snowpack is an interface buried mid-December, now down 40-100 cm. This layer appears to be well bonded in many parts of the region giving moderate results in snowpack tests, but not reactive to skier loads.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs have been forming on mainly southwest to north aspects behind exposed terrain features. Slabs found on south aspect slopes could become more unstable when the sun is out.
Use ridges or ribs to avoid pockets of wind loaded snow.Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 6th, 2017 2:00PM

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