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Avalanche Forecast

Feb 26th, 2014–Feb 27th, 2014
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
3: Considerable
The avalanche danger rating below treeline will be considerable
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
3: Considerable
The avalanche danger rating below treeline will be considerable
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
3: Considerable
The avalanche danger rating below treeline will be considerable

Regions: South Columbia.

Recent warm temperatures have added another dimension to the puzzle. Watch out as temperatures climb, especially on solar aspects. For more insight, check out the latest Forecasters Blog.

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

The ridge of high pressure continues to dominate conditions for the forecast period. Clear and dry conditions with colder arctic air scheduled to move back into the region. The South Columbias will see a cooling trend with arctic outflow conditions by the weekend.Wednesday night: Freezing level at valley bottom, ridge top winds light-variable.Thursday: Sunny with some cloudy periods, freezing level around 1400m, trace of precipitation, ridge top winds, light to 25 Km/h.Friday: Sunny, freezing level at valley bottom, trace of precipitation, ridge top winds from the north to 20 Km/hSaturday:  Freezing level at valley bottom, light ridge top winds from the south.

Avalanche Summary

Natural avalanches are still occurring up to size 3 in the forecast area, and as temperatures warm up may increase in frequency. We've had one report of a cornice failure that triggered and avalancheConditions are ideal for human triggering right now and we have received numerous reports of skier triggered avalanches, many of which have released quite deep in the snowpack. Several were remotely triggered from a considerable distance and produced large avalanches.

Snowpack Summary

A dense slab with an average thickness of 1.5 metre sits on a nasty persistent weak layer (surface hoar/facet/crust combo) that was formed during the preceding month of cold, dry weather. This weak layer is widespread at all elevations and aspects, and continues to be reactive, even in previously skied terrain. Large settlements and whumpfs have been reported at all elevations. As well, we have received numerous reports of remotely-triggered avalanches indicating the ability of failures in this weak layer to propagate over large distances. Touchy conditions are expected to remain in place longer than we're normally accustomed to. Some Katabatic (down-flowing) winds slab formation is being reported as well.In many wind loaded areas, a slab of up to 2m thick overlies the persistent weak layer creating conditions for very large avalanches. We are getting reports of surface hoar growth and near-surface facetting in protected areas above and below tree line.Weak basal facets exist in some areas, but triggering has now become unlikely. For the most part, the mid and lower snowpack are strong and well consolidated.

Avalanche Problems

Persistent Slabs

A thick storm slab from the last series of storms now lies above a touchy, persistent weak layer. This slab has shown a propensity for remote triggering and propagating over wide distances. In wind-loaded areas the slab may be up to 2m thick.
The new snow will require several days to settle and stabilize.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Use very conservative route selection, stick to simple well supported terrain that is low consequence and free of overhead hazard.>Avoid slopes with glide cracks.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 2 - 5

Wind Slabs

The hazard may increase with rising temperatures and solar warming on South aspects. See the forecasters blog for more information on current tricky conditions.
Avoid freshly wind loaded features.>Travel on ridgetops to avoid wind slabs on slopes below.>Do not travel on slopes that are exposed to cornices overhead.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 4