Avalanche Forecast

Issued: Jan 14th, 2013 10:21AM

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

This forecast is based on a weather model that shows rapidly increasing alpine temperatures on Tuesday. If it doesn’t warm up, then these danger ratings are one notch too high.  See the forecasters blog for warming details.

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 dry conditions. Freezing level are expected to rise up to 2500 m. and the sun to shine in the alpine with valley clouds. Winds should be strong from the Northwest.Wednesday: Dry, sunny and warm conditions persist. Thursday: A cold front should lower freezing levels and bring a trace of precipitation.

Avalanche Summary

A few recent natural slab avalanches up to size 2.5 on steep South and Northwest aspects were reported in the Northern part of the region. There was also several natural and skier triggered slab avalanches up to size 1.5 on various aspects all over the region.

Snowpack Summary

The upper snowpack instabilities that were starting to settle could become unstable again if rapid warming occurs with the forecasted weather for the next 2 days. Read the forecaster blog to learn more about this process. The 50-90 cm of recent snow is sitting over weaker snow surfaces including surface hoar (found especially at and below treeline in sheltered areas), a sun crust (on steep S to SW -facing slopes) and facets. The distribution of buried surface hoar is patchy, but where it exists, it may become touchy again. Recent strong winds have also left wind slabs in the lee of terrain breaks such as ridges and ribs at alpine and treeline elevations. A strong mid-pack overlies a weak facet/crust layer near the base of the snowpack, which is now considered inactive.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Be aware of rapid warming and solar radiation forecasted tomorrow and Wednesday which will most likely weaken the snow surface, possibly triggering an avalanche on the surface hoar layer down around 80 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

Possible - Likely

Expected Size

1 - 5

Wind Slabs

An icon showing Wind Slabs
New 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.
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

Possible - Likely

Expected Size

1 - 5

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