Avalanche Forecast

Issued: Dec 29th, 2016 4:07PM

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

Conservative terrain selection is recommended on Friday. Give the recent storm snow a couple days to settle and stabilize before pushing into big terrain features. Use extra caution on steep sun exposed slopes on Friday afternoon.

Summary

Confidence

Moderate -

Weather Forecast

Mostly sunny conditions are expected on Friday. Alpine winds are forecast to be light to moderate from the north and freezing levels are expected to be around 600 m. Mostly cloudy conditions are forecast for Saturday with sunny breaks in the morning and light snowfall in the afternoon or evening. Alpine winds are forecast to become strong from the northwest and freezing levels are forecast to be around 400 m. A mix of sun and cloud is forecast for Sunday with moderate northeast winds in the alpine and freezing levels falling to sea level.

Avalanche Summary

On Thursday during the storm, the storm snow was reported to be touchy and ski cutting in the early afternoon was produced storm slabs size 1-2 in the North Shore mountains with crowns 30-50 cm thick. Isolated natural activity was observed from steep wind loaded terrain during afternoon in the same area. On Friday, weaknesses within the new storm snow are generally expected to heal quickly. However, wind loaded terrain features may remain reactive to human triggering as well as steep slopes.  Steep sun exposed slopes are also a concern for Friday.

Snowpack Summary

Storm totals on Thursday are expected to reach around 50 cm in the wettest parts of the region. This brings the total storm snow amounts since Monday to around 100 cm in the North Shore mountains. Reports on Thursday suggest the storm snow from the beginning of the week is well bonded and stable, and the new avalanche activity has been isolated to snow that fell on Thursday. Ongoing strong southerly winds during the storm have been loading in leeward and cross loaded features in wind exposed terrain. A crust that formed a week ago is likely down over 1 m. Below this crust, the snowpack is generally considered well settled and stable.

Problems

Storm Slabs

An icon showing Storm Slabs
Storm slabs from Thursday may remain reactive to human triggering on Friday in wind loaded terrain and on steep slopes.  Watch for sluffing of the storm snow from steep terrain features.
Give the new snow time to settle and stabilize before pushing into big terrain.Use conservative route selection, choose moderate angled and supported terrain with low consequence.Avoid freshly wind loaded features.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 30th, 2016 2:00PM