Avalanche Forecast

Issued: Apr 6th, 2016 8:17AM

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

jsmith, Avalanche Canada

South Rockies.

Expect freezing levels to creep up throughout the day. Failing cornices could trigger large avalanches running to valley bottoms. Watch out for what's above your head.

Summary

Confidence

High

Weather Forecast

THURSDAY: Freezing levels creep up to near 3000m in the late afternoon, cloudy in the morning then clearing throughout the day, light-moderate southwest ridgetop winds. FRIDAY: Freezing levels soar to 3500m, sunny, light westerly ridgetop winds. SATURDAY: Freezing level 2700m, sunny, light westerly ridgetop winds.

Avalanche Summary

No new avalanches were reported in this region on Tuesday.

Snowpack Summary

Cornices are large, fragile, and could trigger deep slab avalanches running to valley bottom. 10cm of recent storm snow with moderate westerly winds have created thin wind slabs on lee aspects in the alpine and open treeline. 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 running to valley bottoms. Glide cracks are widespread, active, and best avoided. Low elevation and thin snowpack areas have become isothermal.

Problems

Cornices

This time of year the strength of cornices deteriorates rapidly with solar radiation.

Pay attention to overhead hazards like cornices.>Give cornices a wide berth when travelling 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

Persistent Slabs

Rapid warming commonly awakens dormant weak layers deep in the snowpack.

Choose regroup spots carefully.>Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>Avoid slopes with glide cracks.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Loose Wet

Changes can be rapid, sometimes significant change is possible in a matter of minutes, certainly within an hour or two.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Apr 7th, 2016 2:00PM