Archived

Avalanche Forecast

Apr 16th, 2012–Apr 17th, 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

1: Low

The avalanche danger rating below treeline will be low

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

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: South Coast.

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period

Weather Forecast

TUESDAY: Overcast with sunny breaks and the possibility of very light precipitation. Light southerly winds and 1200m freezing level. WEDNESDAY: Light precipitation possible throughout the day with a weak ridge of high pressure bringing drier conditions in the PM. Winds moderate from the southwest and 1200-1500m freezing levels. THURSDAY: Mostly drier conditions. Freezing levels 1200-1500m.

Avalanche Summary

Recent reports include cornice fall and loose wet avalanches during periods of warming. Full-depth size 2-3 glide avalanches have been sporadically releasing on rock slabs.

Snowpack Summary

Very large cornices are looming. Glide cracks have opened up and pose the threat of large, full-depth releases, especially on steep rocky terrain features at low elevations. At this time of year, snowpack stability tends to decrease during times of warming (e.g. on slopes receiving sunshine, during rainfall, in the afternoon and at low elevations) and improve when the surface freezes. A buried crust/surface hoar layer from late March, within the upper 1.5 m of the snowpack, is reported to have gained strength, but remains a lingering concern.

Avalanche Problems

Cornices

Very large cornices are looming. A cornice fall can act as a heavy trigger for avalanches on the slope below.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 5

Wind Slabs

Wind slabs may develop with incoming snow and wind. Be alert for these behind ridges and terrain breaks.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 4

Wet Slabs

Wet loose or slab avalanches are most likely on steep slopes when temperatures are warm,e.g. on slopes receiving sunshine, during rainfall, in the afternoon and at low elevations. Avoid exposure to slopes which are sporting glide cracks.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 6