Avalanche Forecast

Issued: Apr 21st, 2014 8:01AM

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

ali haeri, Parks Canada

Glacier.

Summary

Weather Forecast

Pineapple weather system bringing a series of disturbances in the coming days. Light precipitation is expected today with freezing levels to hover around 1900m. A stronger pulse will hit the interior tomorrow morning into Wednesday with more precipitation and freezing levels to go to 2100m.

Snowpack Summary

20cm of recent HST overlies a crust in the alpine. Deeper pockets of wind slab formed below ridge crests and on lee features from Southerly winds. Dry snow will be found on due N aspects and on other aspects above 1800m. Several crusts exist in the top meter of the snowpack on solar aspects. Isothermal snow developing on solar asp below tree line.

Avalanche Summary

5 natural avalanches, moist loose and moist slabs, were observed in the highway corridor yesterday east of the Rogers Pass summit ranging in size from 1.5 to 2.0 including one glide crack release.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Loose Wet

With forecast rain and rising freezing levels today expect the hazard to increase at lower elevations. Snow that is wet and not supportive is likely to be unstable on steeper slopes after this mornings crust has broken down.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Storm Slabs

Recent snow has created a 10 to 20cm slab that was reactive to human triggering overtop a crust.

Use caution in lee areas. Recent wind loading have created wind slabs.Use safe ski cutting techniques before entering ski run.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

Buried persistent weak layers can become more reactive depending on how warm it gets or with rain. Remain vigilant about avoiding shallow snowpack areas where the likelihood of triggering these layers is highest.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 4

Valid until: Apr 22nd, 2014 8:00AM