Avalanche Forecast

Issued: Dec 3rd, 2017 4:31PM

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

swerner, Avalanche Canada

South Rockies.

Pockets of reactive wind slab may exist on northeasterly aspects.

Summary

Confidence

Low - Due to the number and quality of field observations

Weather Forecast

Monday: Mix of sun and cloud. Alpine temperatures -10. Ridgetop winds light from the west.Tuesday: A mix of sun and cloud. Alpine temperatures -4 and freezing levels 1200 m. Ridgetop winds light with strong gust from the northwestWednesday: Mostly sunny. Alpine temperatures plus 1 degree and freezing levels near 1500 m. Ridgetop winds light-moderate from the northwest. Expect strong alpine temperature inversions starting Wednesday. For more detail please check the Mountain Weather Forecast.

Avalanche Summary

No new avalanches have been reported from this region. There is potential for triggering wind slabs on leeward slopes and dry loose avalanches from steeper terrain features. Smaller avalanches may step down and trigger larger avalanches on buried weak layers deeper in the snowpack. Please submit your observations this weekend to the Mountain Information Network.

Snowpack Summary

The snowpack remains highly variable with very little information regarding snowpack structure within the region. Average snowpack depths at upper elevations range from 60-110 cm with scoured snow surfaces on southwesterly slopes and deeper pockets of wind slab on northeasterly slopes. Below the surface exists a series of crusts that were buried near the end of November approximately 40 cm and 70 cm down. Deeper in the snowpack a third crust from the end of October exists as a "facet/crust" combo and has been identified as a potential sliding interface where snowpack testing North of the region (Kananaskis Country) is proving hard but sudden collapse results.

Problems

Wind Slabs

Stiff wind slabs could be reactive to rider triggers at treeline and in the alpine on leeward and cross-loaded slopes.

Use ridges or ribs to avoid pockets of wind loaded snow.Watch for whumpfing, hollow sounds, and shooting cracks.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

There are several crusts now buried within the snowpack. Use extra caution in thin snowpack areas where it may be possible to trigger a deeper layer. Triggering a wind slab may also have the potential to step-down to a deeper layer.

Be aware of thin areas that may propogate to deeper instabilites.If triggered wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 4th, 2017 2:00PM