Avalanche Forecast

Issued: Apr 12th, 2016 9:42AM

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.

jsmith, Avalanche Canada

South Rockies.

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

WEDNESDAY: Freezing level: 2100m, mix of sun and cloud, light to moderate westerly ridgetop winds. THURSDAY: Freezing level: 2000m, overcast skies with intense convective flurries,Â moderate easterly ridgetop winds. FRIDAY: Freezing level: 2300m, mix of sun and cloud, light southerly ridgetop winds.

Avalanche Summary

No new avalanches were reported in this region on Monday.

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

Cornices have a nasty habit of running surprisingly long distances.

Give cornices a wide berth when travelling 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 - 6

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

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: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1 - 3

Valid until: Apr 13th, 2016 2:00PM