Avalanche Forecast

Issued: Apr 21st, 2016 9:06AM

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

Avalanche Canada jsmith, Avalanche Canada

Spring Conditions. No overnight refreeze of the snow surface means it will not take much sun to rapidly increase the hazard.

Summary

Weather Forecast

FRIDAY: Freezing Level: 3200m, mostly cloudy, light to moderate southwesterly ridgetop winds. SATURDAY: Freezing Level: 2500m, cloudy with possible flurries, light northwesterly ridgetop winds. SUNDAY: Freezing Level: 2200m, cloudy with possible flurries, light westerly ridgetop winds.

Avalanche Summary

Most commercial operations have closed for the season, and data is becoming sparse.

Snowpack Summary

Monitoring the overnight freeze of the snow surface is very important during the spring. If the snow surface does not freeze overnight or if the crust is only a few cm thick, the effect of daytime heating and solar radiation will weaken the snowpack much more quickly than it would if there is a well frozen thick crust. This is because the crust must first melt before the sun can weaken the snowpack. Deeply buried weak layers in the mid snowpack and near the ground still have the potential to wake up and become active with a rapid warm up. While unlikely, releases on these deeply buried weak layers would result in very large avalanches. Glide cracks are widespread, active, and best avoided. Cornices are large, fragile, and could trigger deep slab avalanches that run to valley bottoms. The snowpack in many areas has become isothermal, meaning the snowpack is 0 degrees Celsius throughout. An isothermal snowpack is more prone to full depth wet slab avalanches during the heat of the day.

Problems

Loose Wet

An icon showing Loose Wet
Solar radiation in the spring can rapidly change the hazard from low to high. Plan ahead and monitor the effect of solar radiation carefully.
Watch for surface clues such as sluffing off of cliffs and pinwheeling. These are red flags that should prompt you to reevaluate the conditions. >Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Wet Slabs

An icon showing Wet Slabs
No overnight surface refreeze will increase the potential for sporadic deep wet slab release.
Be aware of the potential for large, deep avalanches. >Avoid slopes with glide cracks. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

3 - 6

Cornices

An icon showing Cornices
Be sure there is more than air under your feet when traveling on corniced ridges.
Cornice releases have the potential to trigger deeply buried weak layers. >Pay attention to overhead hazards like cornices. >Stay well back from cornices. >

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1 - 4

Valid until: Apr 22nd, 2016 2:00PM

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