Archived

Avalanche Forecast

Jan 11th, 2019–Jan 12th, 2019

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

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

2: Moderate

The avalanche danger rating at treeline will be moderate

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

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Little Yoho.

Recent windslabs are becoming the main concern in Little Yoho's fatter snowpack areas. There are however many thinner snowpack areas here where triggering slabs over basal facets are a big concern: Field Ice Climbers beware.

Weather Forecast

Freezing levels are forecast to approach 2200m daily through Monday which may keep slabs sensitive to human triggering. Watch for potential temperature inversions. Moderate to Strong SW winds should start to diminish Saturday and it looks to be cloudy near the divide until Monday when the potential for solar inputs looks likely.

Snowpack Summary

Snowfall since Jan2 has been redistributed by southwest winds yielding extensive wind effect in the alpine. In thick snowpack areas, the Dec 10th weak layer of facets is now down 100-150cm with a stronger snowpack below. In thin snowpack areas, there is little separation between Dec 10 and the weak depth hoar/ facets sitting 40 cm above the ground.

Avalanche Summary

A group just outside of the Lake Louise ski area above the Pika Flats at treeline triggered a sz 2 slab 80cm deep failing 40m wide and running 200m on a SW aspect today. The snow safety team at Sunshine Village saw several windslabs fail in the last 24 hrs one of which scrubbed to the ground and produced a large avalanche off of the Monarch.

Confidence

Freezing levels are uncertain on Saturday

Avalanche Problems

Wind Slabs

Moderate to strong SW winds have moved a significant amount of snow over the last three days. Expect widespread wind effect in the alpine and get your guard up as you enter open areas at treeline.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2.5

Persistent Slabs

The Dec.10 layer of facets and some surface hoar are down 130+cm at treeline in the fatter snowpack areas more typical in this region. The sensitivity of this layer seems more concerning at lower elevations but few observations have been made so far

Convex features and steep unsupported slopes will be most prone to triggering.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 3.5