Avalanche Forecast

Issued: Dec 21st, 2015 8:21AM

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

Avalanche Canada pgoddard, Avalanche Canada

Touchy storm slab conditions. Back off into simple terrain if you encounter signs of instability, like cracking or whumpfing.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

An unsettled flow continues to affect the southern part of the province, bringing snow and cold temperatures. Models disagree on snowfall amounts, but most snow is likely to fall in the far south. Tuesday:  5-15 cm; Wednesday: 5-15 cm; Thursday: 5-20 cm. Winds are generally light, but may increase with the passage of frontal systems.  The freezing level stays near surface. For more details check out http://www.avalanche.ca/weather. 

Avalanche Summary

Skiers triggered numerous loose dry and soft slab avalanches on Sunday in the size 1-2 range. There were also numerous natural loose dry and storm slab avalanches out of steep terrain.

Snowpack Summary

Up to 50 cm of low density snow now covers various surfaces, including the reactive mid-December surface hoar. This surface hoar can be found on all aspects in protected areas, but does not seem to be widespread across the region. In many areas, the new snow sits on top of a thin rain crust. No matter what the new snow overlies, it is bonding poorly in most steep terrain. Moderate SW winds recently formed fresh wind slabs on lee features at treeline and in the alpine. At treeline elevation the early December crust, down around 50-100 cm, is thick and supportive, and may be capping deeper weaknesses. It may also be providing a good sliding surface for the odd larger avalanche.

Problems

Storm Slabs

An icon showing Storm Slabs
The combination of new snow and SW wind has created slabs on lee features at alpine and treeline elevations. Below treeline, the storm slab may be extra touchy where it sits on buried surface hoar.
Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Avoid freshly wind loaded features and use ridges/ribs to sneak around these problem areas.>On steep slopes, pull over periodically or cut into a new line to manage sluffing.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Dec 22nd, 2015 2:00PM

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