Avalanche Forecast

Issued: Nov 25th, 2012 8:09AM

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

Parks Canada danyelle magnan, Parks Canada

Recent reports and snowpack test results indicate a lot of variability. Look for signs of instability and check the snowpack before committing to your line. Strong sun forecast for tomorrow may increase avalanche danger on solar aspects

Summary

Weather Forecast

Unsettled NW'ly flow is pushing across the area. Expect isolated flurries, sunny breaks, and light NW winds today. A ridge of high pressure is building tomorrow bringing mostly sunny skies, and light W-NW winds. High solar inputs are forecast.

Snowpack Summary

The storm slab is most reactive where it overlies a sun crust down ~30cm on steep solar aspects in the alpine. The Nov 6 crust is down 80-120cm with facets around the crust. Test results vary; from sudden planar to sudden collapse; and comp test easy to deep tap test hard.

Avalanche Summary

Recently, windloading is the trigger. Yesterday, 4 loose avalanches size 1.5-2 ran from steep terrain. On Thurs there were 2 size 1.5 skier accidental avalanches triggered on the Nov 16 crust. No avalanches have stepped down to the Nov 6 crust, yet.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Storm Slabs

An icon showing Storm Slabs
The storm snow is settling into a cohesive slab. It is most reactive on steep solar slopes in the alpine where it overlies a sun crust. Skiers have accidentally triggered avalanches on this layer that propagated across terrain.
Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.Assess start zones carefully and use safe travel techniques.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

An icon showing Wind Slabs
Strong southerly winds during last weeks storm transported snow, loading lee slopes and forming windslabs. These windslabs have been buried by new snow and may be difficult to recognize.
Avoid traveling on ledges and cliffs where small avalanches may have severe consequences.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 26th, 2012 8:00AM