Archived

Avalanche Forecast

Jan 20th, 2013–Jan 21st, 2013

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

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

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: Glacier.

Thin cloud should reduce solar effects today. If the clouds break watch for signs, like sluffing off of cliffs, that the snowpack is warming up. Solar triggered avalanches are possible. Minimize exposure to cornices which may be weakened by the sun.

Weather Forecast

Dry and mild conditions will continue due to the ridge of high pressure through Tuesday. Temps will rise to just below 0'C, with moderate to strong S to W winds.Â Thin high cloud should reduce solar effects today, but Monday looks clear with strong solar. Later on Tuesday the next system will move in, possibly (hopefully) bringing more snow.

Snowpack Summary

Sustained moderate to strong southerly winds have created pockets of touchy windslab on lee slopes and windeffect on exposed slopes at treeline and above. A layer down 30-50cm has been most reactive on steep solar aspects where it is composed of facets/surface hoar on a crust. Below this the snowpack is well settled and generally strong.

Avalanche Summary

Skiers have reported triggerable hard windslabs. On Friday, a size 1 triggered at the top of "Puff Daddy" on a NE aspect at treeline, fractured 5m above a skier. It was 30cm deep and ran 50m. There continue to be a few large (sz 2-3) natural avalanches observed daily. These have been triggered by windloading and are from paths with lee start zones.

Confidence

Avalanche Problems

Wind Slabs

Sustained southerly winds have been loading lee and cross-loaded slopes and creating touchy windslabs. They have been human triggered, often fracturing above the skier. Be especially cautious approaching breaks in terrain and convex rolls.

Be cautious as you transition into wind affected terrain.Use safe ski cutting techniques before entering ski run.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Persistent Slabs

A persistent layer down ~40cm remains a concern. It has been most reactive on steep, solar aspects and produced several skier triggered avalanches last week. Human triggering is still possible, or windslabs may step down to this layer.

Choose well supported terrain without convexities.Ride slopes one at a time and spot your partners from safe locations.

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

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3