Avalanche Forecast

Archived

Apr 20th, 2025–Apr 22nd, 2025

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Below Threshold.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Below Threshold.

Regions

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

A Spring storm is possible bringing up to 30cm. If this happens, be alert on changing conditions and the hazard to increase to Considerable.

Spring conditions exist in most location. North aspects may still hold the Persistent problem, be cautious and inspect. This is the time of year to start early and finish early. Watch for warming and direct solar input when travelling through terrain. Check out Avalanche Canada's blog on Spring Conditions for some good tips.

Confidence

Moderate

Avalanche Summary

No recent activity observed or reported.

Snowpack Summary

Expect 10-30cm of snow with the incoming storm. The closer the snow amounts approach the 30cm mark, expect the hazard to increase to Considerable.

This snow is likely to settle fast and be mildly affected by the light forecast winds. Expect to find a denser layer buried under the new snow in the alpine on all aspects. These buried denser layers could be sensitive to triggering where the underlying surface is a smooth crust. Otherwise, expect a melt-freeze surface layer (or near surface) on all solar aspects as well as all aspects at lower elevations. Higher elevation northerly aspects still hold dry snow. Cornices are starting to sag in the mid-April heat, and some recent collapses have been observed.

Timing is everything. As surface crusts break down during the day the stability will begin to decrease. Start early and finish early.

Weather Summary

It is Spring time so the weather and snow amounts can vary a lot. See the chart below.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Be careful with wind-loaded pockets, especially near ridge crests and rollovers.
Wind slabs are isolated, but may remain reactive.
Even brief periods of direct sun could produce natural avalanches.

Problems

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.

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.