Avalanche Forecast

Archived

Mar 28th, 2013–Mar 29th, 2013

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Cariboos.

Danger could INCREASE TO CONSIDERABLE with intense solar input on south and west aspects. Be aware of changing conditions.

Confidence

Good

Weather Forecast

Expect a beautiful spring weekend!Friday: There is a chance of some high patchy clouds with light northerly winds and alpine temperatures climbing to 2. Freezing levels could peak at 2000m.Saturday: Mostly clear, with continued light northerly winds and alpine temperatures reaching 3. Expect slightly higher freezing levels.Sunday: Continued clear skies, with lingering northerly winds and alpine temperatures reaching -1.

Avalanche Summary

Natural wet-loose avalanches up to Size 2 continue to be reported from throughout the region on solar aspects. Isolated cornice releases up to 2.0 have also been reported.

Snowpack Summary

Clear, warm days and cold nights have brought Spring's daily melt freeze cycle to the surface snow on sunny aspects into the alpine and all aspects at lower elevations (below 1800m). Surface hoar is growing on high shaded terrain and the cold temperatures have broken down the windslabs in lee features in the alpine. Cornices are huge!The weak layer of buried surface hoar from March 10th is buried more than 100cm in most places, and is giving variable results in snow profile tests. Although unlikely to trigger, this deep persistent weakness remains a concern because of the potential for very large avalanches particularly with heavy triggers such as cornice falls or lighter triggers in thin snowpack areas.

Problems

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.

Cornices

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.