Avalanche Forecast

Issued: Apr 10th, 2016 3:00PM

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

Avalanche Canada jsmith, Avalanche Canada

Spring Conditions. Expect avalanche hazard to increase throughout the day, especially during periods of warm, sunny weather. Failing cornices could trigger large avalanches running to valley bottoms. Watch out for what's above your head.

Summary

Weather Forecast

MONDAY: Freezing level: 2000m, mostly cloudy, light southwesterly ridgetop winds. TUESDAY: Freezing level: dropping to 1500m, 10-15mm of precipitation throughout the day and overnight, moderate to strong southerly ridgetop winds. WEDNESDAY: Freezing level: 1500m, light precipitation, light southwesterly ridgetop winds.

Avalanche Summary

No new avalanches were reported on Saturday.

Snowpack Summary

Cornices are large, fragile, and could trigger deep slab avalanches that run to valley bottoms. 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. There is an old crust layer down approximately 50cm in the Duffey area and north of Pemberton. This layer has generally been dormant but resulted in a couple large avalanches during the last major warming event and produced a couple explosive triggered avalanches on Thursday. With continued warming, this layer could wake-up in isolated locations such as steep, rocky faces. Glide cracks are widespread, active, and best avoided. Low elevation and thin snowpack areas have 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, especially on steep, rocky faces.

Problems

Cornices

An icon showing Cornices
If the sun is shining, cornices present a significant hazard. Even if they don't trigger a slab avalanche when they fall onto a slope, they have a nasty habit of running surprisingly long distances.
Give cornices a wide berth when travelling on or below ridges.>Pay attention to overhead hazards like cornices.>Cornices become weak with daytime heating, so travel early on exposed slopes. >

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 5

Wet Slabs

An icon showing Wet Slabs
Ongoing sunny weather and warm temperatures could lead to destructive wet slabs, especially if there is little or no overnight refreeze.
Avoid rocky, shallow, and/or steep slopes during the heat of the day. >Cornice releases have the potential to trigger deeply buried weak layers. >

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 6

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.
Look for signs of surface instabilities such as pinwheeling and point releasing near cliffs. >Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Apr 11th, 2016 2:00PM