Avalanche Forecast

Issued: Jan 14th, 2013 10:28AM

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

Avalanche Canada slemieux, Avalanche Canada

Summary

Confidence

Poor - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

Monday night and Tuesday: A high pressure dominates the weather bringing clear skies in the alpine and valley clouds because of the inversion. Alpine temperatures should rise above or near near zero degrees and winds are forecasted to be strong from the West. Wednesday: The high pressure weakens allowing light precipitation. Freezing levels will be around 700 m. and moderate winds from the West.Thursday: Similar conditions expected with slightly more precipitation forecasted, strong West winds and warm temperatures.

Avalanche Summary

A few recent natural slab avalanches up to size 2 and a skier triggered avalanche size 1.5 were reported. The failure plane was the late December surface hoar.

Snowpack Summary

The surface hoar layer down 60-80 cm has started to be reactive in some areas with the warming.  There is also signs of intense wind effect in the alpine by recent strong NW winds leaving shallow areas and hard windslabs on lee side of ridges. The continuing warming and solar radiation forecasted for tomorrow will maintain the weakening of the snowpack trend. Read the forecaster's blog to learn more about this process. Triggering a surface instability could step down to the deeper persistent instability creating bigger avalanches. A strong mid-pack overlies a weak base layer of facets and the early November crust. Even though the crust has been unreactive for a while, professionals are concerned about it again with the warming which could awake it, especially in shallow areas at treeline and in the alpine.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Be aware of rapid warming and solar radiation which will weaken the snow surface, possibly triggering an avalanche on the surface hoar layer down 80 cm or down to the deeper persistent weak layer from early November.
Avoid shallow snowpack areas where triggering is more likely.>Avoid paths that have not avalanched recently.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 5

Wind Slabs

An icon showing Wind Slabs
Be aware of rapid warming already happening and forecasted solar radiation which will weaken the snow surface and possibly act as an avalanche trigger.
Cornices become weak with daytime heating, avoid traveling on slopes exposed to them.>Be aware of the potential for wide propagations due to the presence of hard windslabs.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Jan 15th, 2013 2:00PM