Avalanche Forecast

Issued: Apr 9th, 2015 8:00AM

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

Parks Canada danyelle magnan, Parks Canada

We are in for one more beautiful spring day! Conditions and hazard will vary throughout the day with aspect and elevation; warm temps and strong solar are the big factors. Be increasingly cautious as things warm up.

Summary

Weather Forecast

One more sunny day before a cold weather system. Today expect strong solar with freezing levels to 2200m, above 0 alpine temps and light winds will keep things warm. Friday expect inverted temps with wet flurries, freezing levels rising back to 2200m and gusty SW winds. Saturday expect up to 20cm, temps below freezing and gusty westerly winds.

Snowpack Summary

Melt freeze cycle below 2500m is forming a strong 20cm thick crust. In the top meter of the snowpack there are multiple crusts that are reactive to tests but would likely need a large trigger. Dry facetted snow can still be found on northerly and shaded aspects above 1900m. Isolated pockets of reactive wind-slab exist at ridge-crest.

Avalanche Summary

On Monday there was a skier triggered avalanche at the top of the Forever Young couloir. A thin windslab was triggered at the top resulting in a size 2.0 that ran 400m. Daily there continue to be a few natural solar triggered loose wet avalanches to size 2.5. Cornice failures have also been triggering slabs in isolated locations to size 2.0

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Cornices

An icon showing Cornices
Warm afternoon temps and lots of solar are causing cornice failures, which is the primary trigger of recent slab avalanches. Even if they don't trigger an avalanche, a car sized block of cornice hurtling downslope is worth avoiding.
Stay well to the windward side of corniced ridges.Cornices become weak with daytime heating, so travel early on exposed slopes.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

2 - 3

Loose Wet

An icon showing Loose Wet
Moistening snow and signs of loose avalanches pouring off cliffs are indications that the upper snowpack is weakening. Probing with your pole can help to assess if the crusts are breaking down; if they are it's time to move into the shade.
Minimize exposure when the solar radiation is strong, especially if snow is moist or wet.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
Weak layers in the top meter of the snowpack may become more reactive as the snowpack warms with daytime heat. Cornice falls are the most likely triggers of large deep avalanches failing on these layers.
Caution around convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Apr 10th, 2015 8:00AM