Avalanche Forecast

Archived

Mar 5th, 2016–Mar 6th, 2016

Alpine

Natural avalanches possible, human triggered probable.

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, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Kananaskis.

Wind and high freezing levels will be the issues contributing to the avalanche problems. Windslabs and loose wet avalanches will be the priority issues for Sunday. Pay particular attention to steep south facing terrain where melt-freeze crusts exist.

Confidence

Moderate

Weather Forecast

Cloudy with light flurries, 4-5cm of snow. Alpine temperature is 0 deg. Southwesterly flow to 30 km/h and gusting up to 60km/h. Freezing levels to 2300 meters.

Avalanche Summary

Yesterday a few slab avalanches were reported in the far east edge of our forecast region to size 2.0. as well as a few loose dry to size 1.0.

Snowpack Summary

High freezing levels and precipitation falling as rain is adding heat to the upper snowpack and consequently the surface is moist which diminishes ski quality and decreases snowpack stability. Moist snow was reported to the top of Smut's Pass (2330 meters) and so we suspect moist snow on all aspects to approximately 2400 meters or higher. There are several melt freeze and sun crusts in the upper 50cm of the snowpack and the Jan 6th facets are buried 60-80cm deep. In shallower snowpack areas, the snowpack will far less supportive as the midpack and basal layers are largely facetted.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

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.

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.