Avalanche Forecast

Issued: Apr 14th, 2016 10:37AM

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 ghelgeson, Avalanche Canada

Friday is probably the last reasonable day for a big objective for the foreseeable future, as a significant warm up is expected to begin Saturday.  Watch for the odd wind slab in the alpine.

Summary

Weather Forecast

We can expect reasonable overnight temperature recovery both Thursday and Friday night before a wave of very warm air crashes into the South Rockies Saturday.  FRIDAY:  Freezing level beginning at 1500 m, rising to 2500 m in the afternoon, mostly clear skies, some cloud building in the afternoon, no significant precipitation, light to moderate southwest wind.  SATURDAY: Freezing level beginning around 2000 m, climbing to 2500 m in the afternoon, scattered cloud cover, no significant precipitation, light to moderate southwest wind.  SUNDAY: Freezing level beginning around 2500 m, climbing to around 3500 m in the afternoon, no significant precipitation, clear skies, light variable wind.

Avalanche Summary

No new avalanches have been reported in this region in the last few days, however loose wet avalanches to size 2.5 have been a regular occurrence over the last week.

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. 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. 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.

Problems

Cornices

An icon showing Cornices
Cornices loom over many ridge lines and should not be trusted!  Falling chunks of cornice could run surprisingly far.
Give cornices a wide berth when traveling on or below ridges. >Cornices become weak with daytime heating, so travel early on exposed slopes. >Pay attention to overhead hazards like cornices. >

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

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

3 - 5

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.
Parking, eating lunch, and regrouping in runout zones is bad practice.>Avoid rocky, shallow, and/or steep slopes during the heat of the day.>Avoid slopes with glide cracks.>

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

Unlikely

Expected Size

1 - 3

Valid until: Apr 15th, 2016 2:00PM