Archived

Avalanche Forecast

Mar 30th, 2015–Mar 31st, 2015

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

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

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: South Coast.

Large and destructive avalanches will remain a concern long after the stormy weather has ended. See this blog post for additional info: http://bit.ly/1HHQrK2

Confidence

Fair - Due to the number of field observations

Weather Forecast

A general cooling pattern is expected for the forecast period. On Tuesday, Wednesday and Thursday only trace amounts of new snow are expected each day with the possibility of occasional sunny breaks. Ridgetop winds should remain light to moderate from the northwest with daytime freezing levels hovering at about 1300m

Avalanche Summary

Largely due to inclement weather, recent reports have been fairly scarce. For a little over a week, there have been consistent reports of avalanches to size 2.5 occurring on the mid-March persistent weak layer. Some avalanches have occurred naturally and many have been remote triggered from up to 100m away.

Snowpack Summary

This region has a very serious persistent slab problem that exists under the upper layers of dense storm snow. Depending on how much recent snow has fallen, a facet/crust persistent weak layer buried mid-March lies anywhere from 40-120 cm below the surface. Avalanches have continued to run on this layer at upper treeline and alpine elevations, especially in the north of the region. Snowpack layers deeper than this critical interface are reported to be generally well-settled and strong.

Avalanche Problems

Persistent Slabs

A deeply buried weak layer continues to haunt the region, especially in the north where large and destructive avalanches will remain a concern for some time. Conservative terrain selection remains critical.

Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>Resist venturing out into complex terrain, even if you observe no obvious signs of unstable snow.>Remote triggering is a concern, watch out for adjacent slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 3 - 6

Wind Slabs

New snow and wind on Monday night will add to an ongoing wind slab problem. Watch for triggering in high elevation lee terrain.

Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Be alert to conditions that change with elevation.>

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 3