Avalanche Forecast

Archived

Apr 20th, 2025–Apr 21st, 2025

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Below Threshold.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Below Threshold.

Below Treeline

Below Threshold.

Alpine

Natural avalanches unlikely.

Treeline

Below Threshold.

Below Treeline

Below Threshold.

Regions

Banff Yoho Kootenay, Banff, East Side 93N, Kootenay, Lake Louise, LLSA, Sunshine, West Side 93N, Field.

10–20 cm of new snow is expected with minimal wind, which will improve ski quality. However, watch locally for how this is bonding to harder surfaces below.

The deep layers have been inactive, but weak facets and depth hoar still exist.

Confidence

Moderate

Avalanche Summary

No new avalanches were observed or reported over the last 72 hours.

Snowpack Summary

A few cm of snow accumulated above ~2000m on Sunday. Below this, surface crusts exist on solar aspects to ridgetop and on all aspects at treeline and below. On northerly aspects, 10-30 cm dry snow with isolated wind effect in lee areas of the alpine. The March 27 crust is 30-70 cm deep and extends to about 2500m. Below the settled midpack, there are still facets and depth hoar to the ground.

Weather Summary

Monday: 10-20cm of snow is possible in the East, but the amount is highly uncertain. Winds should remain light from the NW, and treeline temperatures will stay below freezing. See image below for details.

Terrain and Travel Advice

Even brief periods of direct sun could produce natural avalanches.

Problems

Loose Dry

Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.

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.