Avalanche Forecast

Issued: Apr 11th, 2016 8:09AM

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. Always keep overhead hazard at the forefront of your mind and remember that big pieces of terrain can have big consequences.

Summary

Weather Forecast

TUESDAY: Freezing level:1500m, 10-15mm of precipitation, moderate to strong southwesterly ridgetop winds. WEDNESDAY: Freezing level: 1500m, overcast skies with chance of very light precipitation(0-5mm),  light to moderate southerly ridgetop winds. THURSDAY: Freezing level: 1900m, mix of sun and cloud, light southerly ridgetop winds.

Avalanche Summary

No new avalanches were reported on Sunday.

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
Cornices have a nasty habit of running surprisingly long distances.
Cornices become weak with daytime heating, so travel early on exposed slopes. >Pay attention to overhead hazards like cornices.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 6

Wet Slabs

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 7

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

1 - 3

Valid until: Apr 12th, 2016 2:00PM