Avalanche Forecast

Archived

Mar 13th, 2021–Mar 14th, 2021

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, 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, human triggered possible.

Regions

Kananaskis.

Avalanche hazard on solar aspects will increase to CONSIDERABLE or higher with the intense solar radiation. Start your trip early and finish early. Avoid exposure to solar aspects and cornices after mid-morning. Sheltered polar aspects still have dry snow.

Confidence

High -

Weather Forecast

Sunday will be a mix of sun and cloud with moderate to strong SW winds. Overnight temperatures near -9 will climb quickly to around +3 at treeline by late morning. Freezing levels could reach as high as 2700 to 3000m.

Avalanche Summary

Several loose wet up to size 1.5 were observed, mainly on steeper solar aspects.

One large naturally triggered size 3 slab avalanche was observed on a SE aspect in the Alpine. This slab exhibited wide propagation, was approximately 60cm deep and occurred after only a couple of hours of sun shining directly on it.

Snowpack Summary

The snowpack continues its transition to Spring. Moist snow on Saturday up to at least 2600m on solar aspects, and likely higher. This will turn into a crust by morning, but will quickly melt again by late morning on Sunday. Expect loose wet avalanches on solar aspects and sensitive cornices when they exposed to sun/heat. On non-solar aspects there are still some buried wind slabs in the upper 60 to 80cm of the snowpack that are worth investigating before committing to bigger terrain.

Terrain and Travel

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
Cornices become weak with daytime heating.
Avoid rock outcroppings, convexities, and anywhere the snowpack is thin and/or variable.
Be alert to conditions that change with elevation and sun exposure.

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.

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.

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.