Archived

Avalanche Forecast

Dec 31st, 2015–Jan 1st, 2016

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

2: Moderate

The avalanche danger rating below treeline will be moderate

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

2: Moderate

The avalanche danger rating below treeline will be moderate

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

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Purcells.

Extra caution!There have been two large skier-triggered slab avalanches near Kimberley and one near Golden in the last week.

Confidence

Moderate

Weather Forecast

A dominant ridge of high pressure brings light northerly winds, sun and increasingly mild temperatures in the alpine. Below about 1700 m, expect valley cloud, flurries and cold temperatures. Alpine temperatures are expected to reach 0 degrees by Friday afternoon and climb above 0 through the weekend. For more details check out https://avalanche.ca/weather.

Avalanche Summary

On Thursday, a skier triggered a size 2.5 slab on a NW aspect at about 2500 m near Golden. It is thought to have failed on the early Dec persistent weak layer, down 30-60 cm. There has also been activity clustered in a region to the west of Kimberley. On Tuesday, a skier triggered a size 2 persistent slab. Last Sunday, a skier triggered a size 3 slab. Skiers also remotely triggered a size 2 slab the week before. These all failed on the early December surface hoar layer and were on all aspects between 1600 m and 2100 m. Small loose dry avalanches and cornice falls have also been reported.

Snowpack Summary

Conditions are variable across the Purcells. In the south (west of Kimberley), a prominent layer of large buried surface hoar is reactive to human triggers. In this part of the region, it is buried down 40 cm with a cohesive slab above it. Further north, it is 60-120 cm down and has been sporadically reactive to skiers on NW facing alpine slopes near Golden. At alpine elevations, this interface exists as a surface hoar/ facet layer sitting on a crust. The lower snowpack is generally considered to be well settled.New and old wind slabs may be found in the lee of ridges and ribs on a variety of slopes.

Avalanche Problems

Persistent Slabs

Skiers have triggered four large persistent slab avalanches in the last couple of weeks. The weak layer is down 40-60 cm and exists at different elevations in different parts of the region.

Dig down to find and test weak layers before committing to a big line. >Avoid exposed alpine faces, especially in the north of the region.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved, especially in the south of the region.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 4

Loose Dry

As the temperatures in the alpine continue to rise, the sun will pack more punch. Loose avalanche activity is expected to continue from steep, rocky, sun-exposed slopes. The volume of dry snow could push you around.

Be aware of party members below you that may be exposed to your sluffs. >Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. >Minimize exposure to steep sun exposed slopes when the solar radiation is strong. >

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Wind Slabs

Soft wind slabs may be reactive to the weight of a person below ridges and ribs.

Be cautious as you transition into wind affected terrain. >Use ridges or ribs to avoid pockets of wind loaded snow. >

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 2