Avalanche Forecast

Archived

Apr 20th, 2024–Apr 21st, 2024

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Below Threshold.

Regions

Kananaskis, Bow Valley, Highwood Pass, North 40, Spray - KLakes.

Spring is creeping higher everyday. The alpine isn't quite there yet, but its close. Keep an eye out for local instabilities from wind loading and new snow.

Confidence

High

Avalanche Summary

Nothing was seen or reported today.

Snowpack Summary

The temperatures today exceeded the forecast, and reached a high of 5 degrees at Burstall Pass. With the clear skies, expect any sun exposed slope to have a surface crust by tomorrow morning. The shady areas above 2300m still have dry snow. As the winds arrive windslabs will likely form in immediate lee areas above treeline. The collection of sun and/or temperature crusts are helping to keep the deeper persistent layers from being a problem.

Weather Summary

Light snow is predicted to start overnight Saturday and bring 3-6cm. Temperatures will remain steady at -4. Ridge winds will be strong out of the SW to W. Valley bottom winds will be moderate and gusty, likely from a variety of direction.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Recent wind has varied in direction so watch for wind slabs on all aspects.

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.