Avalanche Forecast

Archived

Apr 22nd, 2025–Apr 23rd, 2025

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.

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.

Travel in the early morning hours and watch for sun-triggered wet loose avalanches.

Confidence

No Rating

Avalanche Summary

Sunshine patrol reported observing a distant cornice failure on the Monarch in the Sunshine backcountry. They estimated it was not larger than a size 1.5, and that it was unlikely to have triggered a slab. Otherwise, no avalanches observed or reported on Tuesday.

Snowpack Summary

There is up to 15cm of settled storm snow at treeline over top of well developed crusts on solar aspects (to ridgetop), and on crusts at all all aspects treeline and below. On north facing alpine slopes there is 20-30 cm of dry snow over firmer surfaces. The March 27 crust is 30-70 cm deep and extends to about 2500m. Below the settled mid-pack, there are still weak facets and depth hoar to the ground.

Weather Summary

Clear skies and light winds bring stable conditions. Valley temperatures will reach near 5°C, while ridgetops remain seasonably cold around -8°C. A cool, quiet pattern for early starts and fast travel.

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.

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.