Archived

Avalanche Forecast

Apr 13th, 2012–Apr 14th, 2012

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

3: Considerable

The avalanche danger rating below treeline will be considerable

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

3: Considerable

The avalanche danger rating below treeline will be considerable

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

3: Considerable

The avalanche danger rating below treeline will be considerable

Regions: Northwest Coastal.

Confidence

Fair - Freezing levels are uncertain for the entire period

Weather Forecast

Saturday: A mix of sun and cloud. Freezing level around 1500 m. Minimal wind.Sunday: Dry, with increasing cloud and winds increasing from the SW in the afternoon. Freezing level around 1200 m. Monday: Light precipitation. Moderate SW winds. Freezing level around 1200 m.

Avalanche Summary

Several natural glide avalanches were reported this week on E to SW aspects below treeline, in the size 2-3.5 range. Wet loose avalanches up to size 2.5 were also observed in response to warming and sunshine. Last week, a large icefall triggered a slab in the Bear Pass area, creating a size 4 avalanche.

Snowpack Summary

Glide cracks have opened up and pose the threat of large, full-depth releases, especially on steep rocky terrain features at low elevations. Otherwise, a relatively strong and deep spring snowpack exists, which becomes weak during periods of warm weather or rainfall. Recently, a lack of overnight freezing below about 1500m has left the snowpack weak. Large cornices and ice cliffs pose a threat from above. Pockets of dry snow and surface hoar may still be found on high north aspects. Areas of wind slab may exist near ridge crests.

Avalanche Problems

Wet Slabs

Warm temperatures or rain may continue to weaken the snowpack, especially below treeline. Wet slides can push you around, entrain mass and become surprisingly large. Avoid traveling on or underneath any slopes which sport glide cracks.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 7

Cornices

Overhead hazards including cornices and ice cliffs can act as a heavy trigger for very large avalanches on the slope below.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 5