Archived

Avalanche Forecast

Apr 1st, 2013–Apr 2nd, 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

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

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

1: Low

The avalanche danger rating in the alpine will be low

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

Regions: Glacier.

Danger is increasing to Considerable through the day on solar aspects. Get an early start! Danger is lower, and ski quality better, on shaded and sheltered aspects.

Weather Forecast

Another warm and sunny day is expected today. Freezing levels will rise to 2700m and winds will shift to the west start to increase to moderate in the afternoon. Overnight a frontal system moves into the region bringing increasing cloud and winds. Freezing levels will lower to 1800m and light precipitation is expected for Tues and Wed.

Snowpack Summary

Strong solar and warm temps over the past week has resulted in moist surface snow and crusts on all but sheltered N aspects above 1900m. Shallow ridgetops in the alpine are becoming isothermal. On shaded aspects large surface hoar is growing, right to mountain top. A surface hoar/crust layer in the upper meter is becoming isolated and stubborn.

Avalanche Summary

Several glide cracks released yesterday, resulting in size 2.5-3 avalanches. Solar triggered avalanches started around 11am, on S-W aspects. Avalanches are now gouging deeper into the snowpack as it warms up. Below treeline and in shallow areas the snow is becoming weak with warming and can be skier triggered.

Confidence

Intensity of incoming weather systems is uncertain

Avalanche Problems

Loose Wet

Warm temps overnight didn't allow much of a freeze. The sun will quickly break down crusts, and solar triggered avalanches are expected. Get an early start and avoid terrain traps, especially below treeline, where moist slides could pile up deeply.

Avoid exposure to solar aspects overhead, large avalanches may reach the end of run out zones.Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

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

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 2 - 3

Deep Persistent Slabs

Glide cracks, gaping cracks in the snowpack, exist on many slopes and have been failing with the warm temps. They can fail unpredictably, and release the entire snowpack to the ground. Size 2.5 to 3 glide crack avalanches have been occurring daily.

Avoid slopes with glide cracks.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 2 - 4

Cornices

Cornices are large and unsupported. They are more likely to fail with solar warming, and may trigger deeper slabs.

Cornices become weak with daytime heating, so travel early on exposed slopes.Avoid steep slopes below cornices.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 2 - 4