Archived

Avalanche Forecast

Jan 26th, 2018–Jan 27th, 2018

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Jasper.

Avalanche control work today on Parker Ridge today confirmed that triggering a large slab with a light load is quite possible. With isolated natural activity observed today as well, it is clear that the stakes are starting to rise...

Weather Forecast

Saturday will see continued cool temps with cloud and the potential for light flurries. On Sunday a SW flow will bring 5-10cm of precipitation with winds increasing to moderate SW and temperatures rising into the -10C range.. Significant snow may arrive Monday as temps peak at -5 C in the alpine.

Snowpack Summary

Persistent slabs sit above 3 weak interfaces in the top 30 to 50cm of the snowpack. Depth and distribution of these weak surface hoar/facet layers varies with the terrain and vegetation shelter, but they are consistently found in sheltered features at TL and above. Windslabs have developed in open areas TL.

Avalanche Summary

Natural windslab avalanches up to size 1.5 were observed Tuesday in windswept alpine moraine features. These events appeared to be running on the persistent slab interface down 30 to 50cm.

Confidence

Intensity of incoming weather systems is uncertain on Sunday

Avalanche Problems

Persistent Slabs

This problem is made up of 3 significant interfaces in the top 30-50cm of the snowpack and deeper in isolated wind loaded locations. These slabs have been active to skier testing and explosive control work producing a few very significant results.

Watch for whumpfing, hollow sounds, and shooting cracks.Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2.5

Wind Slabs

Last week's storm snow with southwesterly winds has built soft slabs in open features. These were reactive Thursday, failing as small sluffs out of cliff terrain hit the slope.

Be cautious as you transition into wind affected terrain.Be careful with wind loaded pockets while approaching and climbing ice routes.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2