Avalanche Forecast

Issued: Mar 23rd, 2017 8:00AM

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

andrew jones, Parks Canada

Glacier.

Remember two things:Manage the uncertainty of persistent slabs by avoiding large committing slopes. Watch for an increase in hazard on solar aspects and slopes below cornices if and when the sun shines.

Summary

Weather Forecast

A mix of sun and cloud for today during a pause between frontal systems. Even brief appearances of the sun will have a profound effect on the snowpack in steep south facing terrain. Freezing levels will rise to 1400m with SW winds gusting to 35km/h. Precipitation arrives on Friday morning with 15cm of new snow expected by Saturday evening.

Snowpack Summary

10cm of new snow fell over night in generally cool conditions at higher elevations. Strong southerly winds picked up this morning depositing snow in alpine lee's and adding to the already huge cornices. Lingering storm instabilities down 30-60cm are still reactive. Persistent weak layers exists down 150cm and near the base of the snowpack.

Avalanche Summary

A few small loose wet avalanches were observed yesterday in the highway corridor. Natural avalanche activity has subsided since our last major snowfall. Expect to see avalanche activity pick up this weekend as more snow and wind arrives in Rogers Pass.

Confidence

Problems

Wind Slabs

Strong winds overnight have continued to transport new snow to lee features above treeline. Newly formed wind slabs may be poorly bonded to last week's storm snow and may step down to deeper layers if triggered.

Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.Use caution in lee areas. Recent wind loading has created wind slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

The month of March has been characterized by heavy loading of new snow and rain. These events have created an instable snowpack that is verging on a tipping point. Deep weak layers have been failing sporadically leading to large avalanches.

Choose regroup spots that are out of avalanche terrain.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

3 - 4

Valid until: Mar 24th, 2017 8:00AM