Archived

Avalanche Forecast

Mar 23rd, 2016–Mar 24th, 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

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

1: Low

The avalanche danger rating at treeline will be low

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

Regions: Kootenay Boundary.

Give cornices a respectful berth.

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Thursday

Weather Forecast

A frontal system is expected to bring around 10-15 cm snow on Wednesday night, with moderate to strong SW winds and the freezing level around 1500 m. Snow showers linger on Thursday before a ridge brings mixed sun and cloud on Friday and Saturday.

Avalanche Summary

No avalanches were reported on Tuesday. A few small storm slabs were triggered by explosives and a skier on Monday.

Snowpack Summary

Cornices are large and looming in some areas. Recently formed melt freeze/ sun crusts may now be buried by storm snow. Recent warm temperatures have generally helped promote bonding. Several crusts are buried in the upper snowpack, some of which have broken down on sunny aspects. The late February persistent weak layer down 70 to 120 cm remains a lingering concern. Test results are variable, with occasional sudden planar (pop) results. This interface may remain more reactive on northerly (shaded) aspects above about 1700 m, where buried surface hoar has the best chance of preservation. On sunny aspects, this interface may be a crust/ facet layer. It is most likely to be triggered by a cornice fall or from a thin snowpack area.

Avalanche Problems

Storm Slabs

New snow and wind are likely to create storm slabs which could be triggered by the weight of a person.

Be cautious as you transition into wind affected terrain.>Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Cornices

Large cornices are threatening many slopes.

Do not travel on slopes that are exposed to cornices overhead.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 4

Persistent Slabs

While becoming unlikely, a persistent slab could still fail with a large trigger like a cornice fall, or from a thin snowpack area.

Avoid thin areas that may propagate to deeper instabilities.>Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely

Expected Size: 3 - 6