Avalanche Forecast

Issued: Jan 13th, 2013 10:14AM

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 - Intensity of incoming weather is uncertain

Weather Forecast

Sunday night and Monday: The ridge of high pressure that has brought cold temperatures lately is being replaced by a warm front pushing towards the interior during the night making temperatures warm up significantly and leaving some light precipitation during the day. Freezing levels will also be unseasonably high with an inversion that could keep the peaks above zero degrees as well. Cloud cover should also dissipate in the alpine with some mid-level clouds. Winds are forecasted to be moderate from the Northwest.Tuesday: Similar situation for Tuesday with alpine temperatures being well above normal and strong sun radiation. Winds are expected to be light from the West.Wednesday:  Temperatures should start cooling in the alpine and a couple disturbances could bring some light precipitation with similar winds.

Avalanche Summary

No new avalanches were reported in the region.

Snowpack Summary

The upper snowpack instabilities that were starting to settle will most likely become unstable again with the rapid warming forecasted for tomorrow and additional solar radiation on Tuesday.  Read the forecaster's blog to learn more about this process. Last week's storm snow is sitting above weak surfaces including surface hoar (found especially below about 1600 m in sheltered areas) and facets. Where it exists, the buried surface hoar is at a prime depth for triggering by rapid warming. Recent winds have also left wind slabs in the lee of terrain breaks such as ridges and ribs at alpine and treeline elevations. In areas sheltered from the wind, loose snow avalanches could throw you off your feet or carry you into a terrain trap. A strong mid-pack overlies a weak facet/crust layer near the base of the snowpack.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Be aware of rapid warming and solar radiation forecasted as soon as tomorrow which will weaken the snow surface, possibly triggering an avalanche on the surface hoar layer down 80-120 cm. 
Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Avoid paths that have not avalanched recently.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 6

Wind Slabs

An icon showing Wind Slabs
Wind slabs may be found behind terrain breaks such as ridges and ribs. These could be triggered by rapid warming and sun radiation over the next few days. Be aware that they could step down to deeper instabilities.
Cornices become weak with warming, avoid traveling on slopes exposed to them.>Be aware of the potential for wide propagations due to the presence of hard windslabs and buried windslabs.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Jan 14th, 2013 2:00PM