Avalanche Forecast

Issued: Feb 7th, 2017 4:01PM

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

Avalanche Canada rbuhler, Avalanche Canada

The recent storm snow is expected to be touchy on Wednesday, especially in wind loaded terrain. Conservative terrain selection remains critical.Use extra caution around steep south facing slopes if the sun comes out in full force.

Summary

Confidence

Moderate - Freezing levels are uncertain on Thursday

Weather Forecast

A mix of sun and cloud is expected on Wednesday with moderate alpine wind from the west and treeline temperatures around -12C. The next storm system is expected to arrive Wednesday night with models currently showing 5-15 cm of snowfall by the end of day on Thursday. Alpine wind is forecast to become strong from the southwest and freezing levels are forecast to rise as high as 2000 m. Light snowfall is forecast to continue on Friday with strong alpine wind from the southwest.

Avalanche Summary

On Monday, several natural storm slab avalanches up to size 2.5 were observed. Explosives and skiers also triggered storm slab avalanches up to size 2. These recent avalanches have had a typical slab thickness of 30-60 cm. On Sunday, natural and human triggered avalanches up to size 3 were observed on all aspects and elevations above around 1500 m. The recent storm snow is expected to remain touchy on Wednesday, especially where it has been redistributed by the wind. Buried surface hoar, facets, and/or a sun crust underneath the new snow may increase the reactivity and propagation propensity of these storm slabs. If the sun comes out in full force, solar triggered avalanches are possible on south facing slopes.

Snowpack Summary

60-80cm of storm snow has accumulated over the weekend. Strong shifting winds have redistributed the new snow in exposed terrain forming touchy wind slabs. The new snow overlies a highly variable old surface which may include wind affected surfaces, a layer of surface hoar in sheltered areas, facets, and/or a thin sun crust. Recent reports suggest a poor bond between the new snow and the old surface. The mid and lower snowpack are generally well settled and stable but isolated basal weaknesses may exist in shallow snowpack areas.

Problems

Storm Slabs

An icon showing Storm Slabs
The recent storm snow is expected to be touchy on Wednesday, especially in wind affected terrain. A weakness beneath the storm snow may increase the reactivity of these storm slabs.
Use conservative route selection, choose low angled and supported terrain with low consequence.Avoid recently wind loaded terrain features.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 3

Valid until: Feb 8th, 2017 2:00PM