Avalanche Forecast

Issued: Apr 19th, 2016 8:41AM

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

Avalanche Canada triley, Avalanche Canada

Spring Conditions. Record breaking warm weather continues. Expect the likelihood of wet slab avalanches, cornice falls, and loose wet avalanches to increase during the heat of the day.

Summary

Weather Forecast

Clear overnight with light southwest winds and freezing levels around 2000 metres. Clear and sunny on Wednesday with light winds and daytime freezing up to 3500 metres. Thin high cloud developing on Thursday morning with light southwest winds and freezing levels climbing to 3000 metres during the day. Cloudy with convective showers and snow flurries on Friday and the freezing level at 2500 metres.

Avalanche Summary

No new avalanches reported. Most commercial operations in the region have finished their season and data is sparse.

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.. 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 quicker. There is an old crust layer down approximately 50cm in the Duffey area and north of Pemberton. Though mostly dormant, it produced a couple large avalanches during the last major warming event. The forecast hottest weather of the year to date could again test it, especially 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, smooth slopes.

Problems

Wet Slabs

An icon showing Wet Slabs
The likelihood of wet slab avalanches will increase with forecast high freezing levels and strong solar radiation. Areas that do not re-freeze overnight may become very weak early in the day.
Travel early before the heat of the day, and avoid big slopes in the afternoon.>Avoid rocky, shallow or steep slopes during the heat of the day.>Avoid sun exposed slopes, especially where the snow is wet, weak, and mushy.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Loose Wet

An icon showing Loose Wet
Sunny skies and high freezing levels will weaken the surface snow on solar aspects. Shaded aspects in the alpine may warm up enough to release as loose wet avalanches.
Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Start and finish early before the surface crusts melt.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Cornices

An icon showing Cornices
Strong solar radiation and little or no overnight freeze will continue to weaken cornices. Avoid travel beneath cornices.
Pay attention to overhead hazards like cornices.>Cornices become weak with daytime heating. >

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 5

Valid until: Apr 20th, 2016 2:00PM