Archived

Avalanche Forecast

Mar 31st, 2016–Apr 1st, 2016

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

4: High

The avalanche danger rating below treeline will be high

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: Jasper.

Avalanche control is planned for the Columbia Icefields area on Friday afternoon during which time the Parkway will be closed it that area. Maligne Lake road is closed due to avalanche danger.

Weather Forecast

Winds will remainÂ north westerly and freezing levels are expected to reach 2,800m on Friday with the potentially of double digit temperatures close to treeline. Expect sun. Overnight recovery will be minimal. Winds will switch more westerly into the weekend and temperatures will cool slightly bring the freezing down to near 2000m as it does.

Snowpack Summary

The snowpack is heating up and rapidly approaching isothermal conditions at and below treeline. Higher in the alpine and on northerly aspectsÂ more winter like conditions prevail. Cornices are large and of particular concern for their ability to trigger large avalanches along mid pack weakness. Freezing will not occur tonight.

Avalanche Summary

The solar radiation is energizing the snowpack and numerous avalanche have been reported today from all elevations. Both loose moist avalanches and dry slab avalanches have occurred up to size 2. Point release events from steep rocky alpine terrain are able to trigger deeper instabilities creating much larger avalanches that can scrub to ground.

Confidence

Avalanche Problems

Deep Persistent Slabs

This problem is becoming more active. When triggered, it will be big with serious consequences. Warm and sunny conditions will increase this danger. Steep sun facing rocks, cornice failures, and loose avalanches from above are on going.

Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 3

Cornices

Increase occurrence of cornice failures are being noted. It can act as a large trigger initiating deep weaknesses plus their sheer mass, whether or not it initiates an avalanche, would be like being hit by a car.

Cornices become weak with daytime heating. Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.

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

Elevations: Alpine.

Likelihood: Likely

Expected Size: 1 - 2

Loose Wet

This problem will increase with forecasted warm temps and intense solar radiation. The danger rating will rapidly increase particularly on thin snowpack zones and sun facing slopes. Loose avalanches can initiate larger avalanches below.

Be very cautious with gully features.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.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 3