Avalanche Forecast

Issued: Jan 27th, 2015 4:48PM

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

brian webster, Parks Canada

Banff Yoho Kootenay.

Cooler temperatures forecasted for tomorrow should tighten up the snowpack. Watch for lingering windslabs in the alpine.

Summary

Weather Forecast

A mix of sun and cloud through Wednesday and Thursday. A cooling trend is forecasted with freezing levels to valley floors overnight, rising to 1500 meters during the day. Winds from the west in the moderate range.

Snowpack Summary

Very strong westerly winds have seriously blasted the region. Wind pressed snow and wind slabs in lee terrain can be expected in the alpine. On Tuesday the snowpack was isothermal below treeline in many areas, but we expect this condition to improve with forecasted cooler temperatures on Wednesday.

Avalanche Summary

The warm temperatures created a widespread avalanche cycle on Sunday and Monday. Tuesday saw slightly cooler temperatures and less natural activity. Avalanches observed were restricted to isothermal avalanches in shallow snowpack areas below treeline.

Confidence

Problems

Wind Slabs

Very strong SW winds over the past few days have created windslabs in lee terrain above treeline. These slabs have the potential to trigger the deeper layers in the snowpack, making for a large avalanches. Avoid all windloaded terrain.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Deep Persistent Slabs

The basal snowpack remains very weak. The facets and depth hoar near the base of the snowpack will produce large avalanches when triggered.

Be aware of the potential for wide propagations.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Jan 28th, 2015 4:00PM