Avalanche Forecast

Issued: Dec 15th, 2017 4:35PM

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

swerner, Avalanche Canada

Northwest Inland.

Slopes that are sheltered from the wind and sun will likely offer the best riding.

Summary

Confidence

Moderate - Due to the number and quality of field observations

Weather Forecast

Saturday: Cloudy with sunny periods. Alpine temperatures -2 and freezing levels 1000 m. Ridgetop winds strong from the southwest.Sunday: Mix of sun and cloud. Alpine temperatures -3. Ridgetop winds light with strong gusts from the southwest.Monday: MIx of sun and cloud. Alpine temperatures -7. Ridgetop winds light from the southwest.Check out the Mountain Weather Forecast for more detail.

Avalanche Summary

No recent avalanche observations. Please submit your information to the Mountain Information Network. Give info get info.

Snowpack Summary

Snow surfaces are highly variable throughout the region. Solar and temperature crusts have formed on sun-exposed slopes, while stiff, stubborn wind slabs linger in leeward alpine terrain. Feathery surface hoar and surface facets have formed below treeline up to 1500 m. Approximately 30-50 cm of snow sits on two crusts that were buried near the end of November. These crusts are widespread and extend into the alpine. Although snowpack tests have previously shown hard results at these crust interfaces, more recent observations have been limited. Below these crusts, a well settled mid-pack overlies the late October crust near the base of the snowpack. This "crust/facet combo" layer is widespread and has not been reactive to rider and remote triggers since the end of November. These rain crusts will likely be with us all winter but may not pose a problem until we see a significant change in the weather.Average snowpack depths now total 80-140 cm at treeline elevations and up to 160 cm in the alpine.

Problems

Wind Slabs

New wind slabs may be rider triggered. Watch for triggering in higher elevation, wind-exposed terrain.

Be cautious as you transition into wind affected terrain.Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

The late October crust lies near the base of the snowpack with a thin layer of weak, sugary snow above it. This layer should be on a strengthening trend, but a heavy trigger in a thin snowpack area may still be enough to cause it to react.

Be especially cautious in shallow snowpack areas where triggering a deeper layer may be easier.Be aware of the possibility for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 16th, 2017 2:00PM