Avalanche Forecast

Issued: Feb 2nd, 2012 9:27AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Wind Slabs, Storm Slabs and Cornices.

Avalanche Canada triley, Avalanche Canada

Summary

Confidence

Good - Timing or intensity of solar radiation is uncertain on Friday

Weather Forecast

There is a band of warm air at higher elevations that may keep temperatures in the alpine quite warm overnight; probably about -3.0 at 2500 metres. Clear skies should allow the valleys to get slightly below freezing. Friday is expected to be warm with light winds and mostly sunny skies. Valley fog may persist in some areas. Temperatures should drop to near freezing in the valley bottoms overnight. The ridge of high pressure is expected to continue on Saturday, bringing slightly cooler temperatures. Mostly clear skies may produce intense solar radiation during the day on Saturday. Sunday is expected to be mostly clear with light winds and freezing levels up to about 1400 metres.

Avalanche Summary

Reports of loose dry sloughing in steep terrain from several operators in the area up to size 1.5. Explosive control at Kootenay Pass produced several avalanches size 2.5-3.0 on cross loaded slopes with crowns between 50-100 cm.

Snowpack Summary

Another 10-15 cm of snow fell during the day on Wednesday, adding to the recent storm snow. The recent storm snow layer is about 30-50 cm thick and is quite variable across the region. There are a couple of thin crusts buried below the storm snow that have been producing moderate to hard shears in tests. Some areas are still getting sudden planar shears on the mid-december surface hoar layer. The forecast warming trend may weaken the bond on the mid-december layer; particular concern in low snowpack areas.

Problems

Wind Slabs

An icon showing Wind Slabs
Recent windslabs are becoming more stubborn to trigger. Warm temperatures forecast should continue to settle and bond these instabilities.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Storm Slabs

An icon showing Storm Slabs
Recent snowfall has added to the current storm slab problem. Watch for storm slabs on steeper, unsupported features.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 4

Cornices

An icon showing Cornices
Forecast warm temperatures and strong solar radiation may weaken large fresh cornice growth. Cornice falls are a large load that may trigger deeply buried weak layers and cause large avalanches on the slopes below.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 5

Valid until: Feb 3rd, 2012 8:00AM

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