Avalanche Forecast

Issued: Apr 16th, 2016 9:19AM

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, Cornices and Wet Slabs.

Avalanche Canada istorm, Avalanche Canada

Spring Conditions: The heat is on! You need to get out super early, plan to be out of avalanche terrain no later than lunch time, and avoid being on or under weak mushy slopes.

Summary

Weather Forecast

High Pressure will clear out the clouds and warm the temperatures which could remain well above freezing at all elevations for the foreseeable future. SUNDAY: Some high cloud, freezing level rising to around 3500 m by the afternoon, no significant precipitation, light to moderate south wind. MONDAY & TUESDAY: Clear and sunny, freezing level near 3500 m all day, no precipitation, light wind. Overnight temperatures may stay above freezing or the freeze could be short-lived.

Avalanche Summary

No new avalanches reported, but we have very few eyes and ears still in the mountains reporting. 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, and produced a couple explosive triggered avalanches on Thursday. 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

Loose Wet

An icon showing Loose Wet
Summer like temperatures and strong sunshine will likely initiate a fresh round of loose wet activity as the storm snow from earlier this week loses cohesion.
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. >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
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.
Pay attention to cornices and give them a wide berth when traveling on or below ridges. >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 - 6

Wet Slabs

An icon showing Wet Slabs
Rapidly warming temperatures and little to no overnight recovery is the recipe for increasing the potential for deep wet slab release.
Cornice releases have the potential to trigger deeply buried weak layers. Avoid rocky, shallow, and/or steep slopes during the heat of the day. >Travel early before the heat of the day, and avoid big slopes in the afternoon.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

2 - 5

Valid until: Apr 17th, 2016 2:00PM