Avalanche Forecast

Archived

Jan 18th, 2020–Jan 19th, 2020

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 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, human triggered possible.

Regions

Kananaskis.

A big change in the weather is coming - warm temperatures! This may mean that slabs become more sensitive to triggering, and certain terrain (such as steep solar aspects and cornices) should be avoided.

Confidence

No Rating -

Weather Forecast

The cold snap should finally end on Sunday! Mostly sunny skies and temps between -5 and -10 at upper elevations. Winds will be strong from the SW and no precipitation is expected.

Avalanche Summary

One slab avalanche was noted today on a steep Alpine feature on a NW aspect. This slide was full depth and fairly narrow, but ran approximately 250m. It occurred sometime in the past 24 hours.

Snowpack Summary

Wind slabs are present at Treeline and above on N, E and S aspects, while W aspects are scoured down to rock. Ski cutting produced some cracking today on wind loaded slopes immediately below ridge-crest, which indicates that human triggering is possible in the right terrain. Despite a week of very cold temperatures the mid-pack is holding onto it's strength, except in shallow snowpack areas. The basal facets and depth hoar are as bad as ever and are here to stay for the foreseeable future.

Terrain and Travel

Be especially cautious as you transition into wind affected terrain.
Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
Avoid convexities, steep unsupported terrain and rocky outcroppings.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Cornices become weak with daytime heating or solar exposure.

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.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.

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.