Avalanche Forecast

Issued: Nov 27th, 2017 8:15AM

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

ian gale, Parks Canada

Glacier.

Strong winds in the alpine have created a touchy windslab. The rainsoaked snowpack below treeline needs cold temps to regain strength.

Summary

Weather Forecast

Today we can expect a break in the stormy weather. Temps will cool with freezing level down to 800m today giving us an alpine high of -9 deg. We might see sunny breaks in a mostly cloudy day today, with isolated small scale convective flurries. The next low pressure system and associated cold front arrives at Tuesday bringing 10-15cms of snow.

Snowpack Summary

Warm temperatures yesterday with rain created a moist snow surface to ~1900m. Overnight cooling has now turned that into a crust. In the alpine and at treeline 10cm of heavy snow fell and strong winds blew from the south creating windslab. Nov 23 Crust is still the prominent crust down 20-30cm. Below that the snowpack is rain soaked and isothermal

Avalanche Summary

In the Connaught creek drainage, skiers reported two natural size 2 wet slabs off of Mt Cheops, stopping halfway down the runout. Two natural size 2.5's were observed from high Alpine start zones yesterday along the highway, likely triggered by recent snowfall and windloading at ridgetop.

Confidence

Freezing levels are uncertain

Problems

Wind Slabs

Strong to extreme southerly winds overnight have significantly redistributed the snow in the alpine and at treeline. These fresh windslabs will be easily triggered by riders.

Use caution in lee areas. Recent wind loading have created wind slabs.Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wet Slabs

Warm temperatures and rain yesterday have added moisture to an already saturated snowpack below treeline. Cooling temps overnight have created a very thin surface crust but if this crust breaks down there will be very little cohesion in the snowpack

Avoid steep, open slopes.Use extra caution on slopes if the snow is moist or wet.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Nov 28th, 2017 8:00AM