Archived

Avalanche Forecast

Mar 9th, 2014–Mar 10th, 2014

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Banff Yoho Kootenay.

The natural cycle is slowing down but skier triggering of avalanches remains likely. Choose moderate terrain with minimal exposure to large paths, and watch for the effects of daytime heating as we move into more spring like weather. CJ

Weather Forecast

Alpine temperatures between -10'C and -3'C are forecast for the next several days, with a mix of sun and cloud, occasional light flurries, and light to moderate winds out of the West.

Snowpack Summary

85-100cm of storm snow has fallen in the Sunshine, Kootenay and Yoho areas, with 40-60cm around Lake Louise and Bow Summit since Mar 2nd. This storm snow has overloaded the Feb 10th layer of facets, surface hoar and sun crust, causing avalanches with wide propagations. Moderate SW winds have also created wind slabs in open areas above tree line.

Avalanche Summary

A widespread natural avalanche cycle to size 3 occurred on all elevations and aspects today. Much of this is occurring on the Feb 10th layer however we also observed storm slab releases and some deep releases to ground. The cooler temperatures over the next several days will slow down the natural cycle, but skier triggering will remain a concern.

Confidence

Avalanche Problems

Storm Slabs

The recent storm snow and wind slabs will slowly begin to bond to the lower layers in the snowpack but this will take some time. Choose conservative terrain with no overhead hazard until this has a chance to bond.

Be cautious as you transition into wind affected terrain.The new snow will require several days to settle and stabilize.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Persistent Slabs

The Feb 10th layer continues to be reactive in many areas especially at tree line. Avoid any steep terrain until this has a chance to bond.

Dig down to find and test weak layers before committing to a line.Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 3

Deep Persistent Slabs

With the cooling temperatures this will become less reactive to skier traffic. Large triggers such as cornice drops or large slab releases could still cause failures on the basal facets.

Minimize exposure to overhead avalanche terrain, large avalanches may reach run out zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3