Avalanche Forecast

Issued: Dec 18th, 2024 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs and Persistent Slabs.

Parks Canada, Avalanche Canada

Glacier.

A significant storm brought 30cms of new snow with strong winds. Stick to conservative terrain while the new snow stabilizes.

Summary

Confidence

Moderate

Avalanche Summary

Avalanche control at Rogers Pass on Wednesday produced storm slab avalanches to size 3. Visibility was obscured and it was difficult to see the full extent of the avalanche cycle but some avalanches ran full path.

Snowpack Summary

30cm of new snow has fallen with strong gusting Southerly winds. This lands on variable wind slabs already present in the Alpine and at Treeline. A persistent weak layer is down 50-70cm. This interface consists of surface hoar in sheltered locations, a sun crust on solar aspects, and continues to produce moderate-hard sudden results in test profiles. The snowpack's base is comprised of several early-season melt-freeze rain crusts.

Weather Summary

In the wake of the storm we'll have unsettled weather with flurries for the next few days

Tonight Cloudy with flurries, Alp low -9Â°C, mod S winds, Freezing level (FZL) 800m

Thurs Cloudy with Snow flurries to 5cm, Alp high -4Â°C, mod S winds, FZL 1400m

Fri Mainly cloudy, flurries to 5cm. Alp high 1Â°C, light S winds, FZL 2200m

Sat Cloudy with flurries to 7cm, Alp high -3Â°C, mod/gusting extreme W winds, FZL 1900m.

Terrain and Travel Advice

Storm slabs in motion may step down to deeper layers resulting in large avalanches.
Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.

Problems

Storm Slabs

In the last 24 hours there has been 30-40cms of new snow, accompanied by strong/extreme S & West winds. A reactive, cohesive storm slab will form with these conditions and will be easily triggered by riders.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1.5 - 3

Persistent Slabs

60-80cm of snow overlays a layer of surface hoar in sheltered zones, and a sun crust on steep, solar aspects. There has been limited activity on this layer in recent days, but the new load from the incoming storm could re-awaken this problem.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 19th, 2024 4:00PM