Avalanche Forecast

Issued: Jan 29th, 2016 8:00AM

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

danyelle magnan, Parks Canada

Glacier.

Patience is a virtue. The snowpack will need a bit of time to adjust to the new load from the storm. Be conservative in your terrain selection.

Summary

Weather Forecast

Today should be mostly cloudy with flurries and light to moderate SW winds. Temps have cooled and the alpine high today is -4'C. By Sat am we should have received 4cm of new snow. Saturday and Sunday will be similar; mostly cloudy with flurries, light to moderate SW winds and alpine temps around -7'C.

Snowpack Summary

The storm dumped up to ~50cm 48hrs. Temps hovered around 0 up to treeline, settling the new snow into a storm slab rapidly. Strong S'ly winds will have loaded lees further. The Jan 4weak layer, down 60-100cm was rapidly loaded and expected to be touchy in areas where it has not yet failed.

Avalanche Summary

A large natural avalanche cycle occurred yesterday. Most avalanches were size 2-3.5 occurring from all aspects and running to the end of run-outs. The largest avalanche was a size 4 from a steep north facing path off Mt Macdonald. Avalanche control yesterday also produced avalanches to size 3.5. Some avalanches triggered deep slabs below treeline.

Confidence

Problems

Storm Slabs

Up to 50cm fell in 48hrs and settled into a storm slab rapidly. SW winds will have loaded lee slopes, forming even deeper slabs. This slab may be triggered by light loads (like you) and avalanches on this layer may step down to deeper layers.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Ski short pitches and regroup in safe spots.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

Persistent Slabs

A surface hoar layer now down 60-100cm is likely to be touchy after being overloaded by the storm. This layer lingers in many areas and is sporadically reactive, making it tricky to assess. When it fails, however, large avalanches are the result.

Watch for signs of instability such as whumpfing, or cracking. Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 30th, 2016 8:00AM