Avalanche Forecast

Archived

Apr 6th, 2023–Apr 7th, 2023

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

With the exception of the valley bottoms, our current weather trend is keeping the freeze/thaw cycles at bay. Until this changes, we are stuck with a winter snowpack that's stalling out from a stability perspective. A positive change in the snow is a slow process these days.

Confidence

Moderate

Avalanche Summary

We had a report of an avalanche on Tent Ridge and Mt Kidd today. The age is unknow, but suspected to be 2-3 days old.

Snowpack Summary

Not a huge ambient temperature swing today. With a short period above zero, we expect limited additional crust development on all but due south aspects. We are at the time of year when its hard to nail down specific layers. In a more general (and applicable) sense, we have a collection of crusts in the top 1/3 of the snowpack with a known persistent facet problem lingering mid pack on north aspects. And of course, our old friend, the Nov 17 facet layer is still lingering down deep on all aspects. It's bit of a complex situation. The defense strategy? Well, given recent avalanche activity, it's still best to dodge the problem all together and avoid bigger/steeper terrain. Beyond that, dig or probe as you travel to give a better sense of distribution.

Weather Summary

Friday is expected to be cloudy, with a small chance of light flurries, or even a light rain shower in the afternoon. An overnight low of only -5 and a daytime high of +1. Light SW winds, with gusts up to 40km/hr. Light snow is expected for the week end, but at this point amounts are minimal.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Minimize exposure to sun-exposed slopes when the solar radiation is strong.

Problems

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.

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.