Avalanche Forecast

Issued: Mar 8th, 2016 8:02AM

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

Ian Gale, Parks Canada

Glacier.

Use caution when transitioning to wind effected terrain. Watch for sudden intense warming from the sun which will increase avalanche hazard

Summary

Weather Forecast

A weak Pacific system will reaching Rogers Pass this evening bringing a mostly cloudy day with sunny periods this afternoon and potential for isolated convective flurries. Cooler temperatures with afternoon freezing level to 1400m. West winds 15-25kph are forecast today, with an alpine high of -4 and no significant precip.

Snowpack Summary

Windslabs have formed in the alpine from moderate S winds Friday/Saturday. The surface snow became moist yesterday to 1700m but was still supportive to a riders weight. The Feb 27 interface is now down 60cm which consists of crusts on solar aspects and surface hoar/stellars on shaded aspects. This layer was active during Sunday's avalanche control

Avalanche Summary

Highway avalanche control on Sunday produced avalanches up to sz 3.5 but most were in the size 2-2.5 range. One notable from the shoot was a 300+ m propagation on the East face of Mt Cheops. Yesterday a survey of the Connaught valley showed numerous sz 2's had run into the creek from Cheops Pk.

Confidence

Due to the number and quality 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.

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

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 is producing sporadic sudden planar results on field tests in sheltered areas. If triggered large avalanches could result. Daytime heating and solar input today could increase this layer's sensitivity.

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

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 can be difficult to predict but is usually related to sudden heating or new loading. Cornice weight could trigger the deep layers 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 9th, 2016 8:00AM