Avalanche Forecast

Issued: Jan 26th, 2012 9:52AM

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

Avalanche Canada ghelgeson, Avalanche Canada

Summary

Confidence

Fair - Freezing levels are uncertain on Saturday

Weather Forecast

A surface ridge moves into the region Friday keeping the area dry while northwesterly flow aloft keeps scattered clouds in place. Ridgetop winds will be at strong values out of the W near ridgetop Friday & temps will remain cool; Expect a daytime High of -5 and an overnight Low of -10 @ 1500 m. Things begin to change a bit Saturday as the ridge breaks down allowing moist flow in from the pacific. The first storm associated with the new pattern enters the region Saturday night, sticking around through Sunday. Freezing levels are expected to rise to 1300 m Saturday night and the region should 5 -10 cm over the weekend.

Avalanche Summary

Our field team was out in the region Thursday investigating a slide that ran full path. This avalanche path has a SE facing start zone that had been crossloaded by the recent westerly winds. A wind pillow failed high on the slope triggering a size 3 avalanche with a crown as deep as 85 cm. The likely culprit is a crust/facet combo from mid-December.

Snowpack Summary

Last week 40-60cm of snow formed soft slabs over a crust/facet/surface hoar combo which has settled remarkably quickly. Deeper in the snowpack, a surface hoar layer buried in early December remains a concern, as avalanches triggered on this layer would be destructive. There may have been releases on this layer post storm but at this time nothing has been reported. It should be noted that basal facets exist in many parts of the region too. Facets sandwiched between two firm layers in the top metre of the snowpack are being monitored in the south-east.

Problems

Wind Slabs

An icon showing Wind Slabs
Winds are expected to continue to blow at strong values Friday. Expect potentially stubborn wind slabs on slopes lee to the W, SW winds.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Storm Slabs

An icon showing Storm Slabs
Tuesday nights storm brought 10 - 15 cm to the region. Watch for small loose snow avalanches in protected areas & small soft slab avalanches in areas that are exposed to wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Jan 28th, 2012 8:00AM