Archived

Avalanche Forecast

Apr 21st, 2014–Apr 22nd, 2014

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

4: High

The avalanche danger rating below treeline will be high

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Regions: Glacier.

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

Avalanche 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