Avalanche Forecast

Archived

Feb 5th, 2023–Feb 6th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

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

Persistent winds and warm temps have created reactive wind slabs in lee and cross-loaded terrain.

Confidence

Moderate

Avalanche Summary

Nothing new reported or observed.

Snowpack Summary

Is it harder to read the same thing everyday, or write the same thing every day? I'm not sure, but for those who like repetitive stories, grab a comfy chair, here we go...

Still no significant new snow out there. But what little snow we had last week has now been blown around into windslabs at most elevations. Given the recent temperature swings, these slabs could very well be reactive and easily human triggered. Climbers should expect to encounter these reactive slabs in small, but consequential pockets between pitches. Routes like Coire Dubh, Sinatra Falls, This House of Sky will all have pocket slabs present.

In lower areas, or solar aspects there is a thin crust developing from the warm weather. Aside from making poor skiing even poorer, this won't pose much of a problem until we get snow.

Don't forget(who could at this point?) about the deep, consequential depth hoar/facet/sugary snow looming way down below. This remains our principal concern and is not to be taken lightly.

Weather Summary

Monday will be mainly sunny to start, with moderate NW winds and temps climbing to near -3C. By late afternoon a change is coming, and we actually might see some snow!!! As the winds shift to the SW, Tuesday will be cloudy with snowfall amounts between 8 and 12cm! Every little bit helps!

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.

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.