Archived

Avalanche Forecast

Dec 15th, 2013–Dec 16th, 2013

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

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

3: Considerable

The avalanche danger rating at treeline will be considerable

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: Banff Yoho Kootenay.

Increased hazard due to moderate W winds, continued light precipitation and mild temperatures is present especially in areas near the divide where more snow fall has occurred. Minimize exposure to wind loaded areas over the next few days. CJ

Weather Forecast

Continued moderate to strong West winds, light precipitation, and alpine temperatures between -5 and -10'C are forecast over the next three days with a cooling and clearing trend beginning on Wednesday.

Snowpack Summary

25cm of storm snow is present near the divide. Moderate to strong W winds and mild temperatures have formed wind slabs in open areas at tree line and above. The mid pack is facetted but still dense enough to support the weight of a skier in many areas. The October melt freeze crust or a mix of depth hoar and facets is present at the base.

Avalanche Summary

One size 2 natural avalanche slid over the "Heineken Hall" ice climb on Mt Dennis today reaching the bottom of the run out zone. Several size 1 moist sluffs were also observed in the Field area out of steep tree line terrain. One size 2 was observed yesterday on the "Sacre Bleu" ice climb on Mt Rundle. Wind appears to be the trigger in all cases.

Confidence

Intensity of incoming weather systems is uncertain

Avalanche Problems

Wind Slabs

Moderate to strong W winds, mild temperatures and light snowfall are creating wind slabs in open areas at tree line and in the alpine which are beginning to fail naturally in steep alpine terrain and are susceptible to human triggering.

Minimize overhead exposure; avalanches triggered by wind loading may travel long distances.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2

Deep Persistent Slabs

20-25cm of storm snow combined with mild temperatures and wind may start causing failures in the deeper basal facets or on the Oct melt freeze crust. Use caution in steep terrain.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3