Avalanche Forecast

Issued: Mar 7th, 2016 8:00AM

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

percy woods, Parks Canada

Glacier.

Watch for lee slope windslab and use caution progressing into avalanche terrain. Prolonged solar input will increase the avalanche danger.

Summary

Weather Forecast

Cloudy with sunny periods today and isolated convective flurries. Cooler temperatures with afternoon freezing level potentially rising to 1700m. Light S winds with gusts into moderate are forecast. SW winds tonight will accompany another 6cm of snow which should soften the lower elevation crusty conditions.

Snowpack Summary

Windslabs have formed from moderate S winds Friday and Saturday. Expect these slabs to still be sensitive to human triggering. The Feb 27 interface consisting of crusts on solar aspects and surface hoar and stellars on polar aspects is now down 70cm+. This layer was the likely sliding layer for many of the recent larger avalanches.

Avalanche Summary

Widespread avalanche cycle over the weekend producing slides mostly in the size 2-2.5 range. Slides became moist in the lower track and runout of the paths. Highway avalanche control produced a few size 3 avalanches with most in the size 2.5 range.

Confidence

Due to the number of field observations

Problems

Wind Slabs

Strong southerly winds have formed sensitive windslab on alpine and treeline lee slopes and crossloaded features. These remain a concern for human triggering.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

The February 27th interface is now down 70cm and was recently producing sudden planar results on field tests. If triggered large avalanches could result. Solar input today could increase this layer's sensitivity.

Avoid steep convexities or areas with a thin or variable snowpack.Choose conservative lines and watch for clues of instability.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Cornices

Recent wind and storm snow has contributed to rapid cornice formation. Cornice fall has the potential to trigger the persistent weak layer resulting in larger avalanches.

Give cornices a wide berth when travelling on or below ridges.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Mar 8th, 2016 8:00AM