Avalanche Forecast

Archived

Jan 25th, 2023–Jan 27th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely.

Regions

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

Snow is hopefully coming tomorrow. As tempting as it will be to rush out and ski, use caution as our snowpack isn't set up well for rapid loading.

Confidence

High

Avalanche Summary

A few loose dry sluffs today in gullies. Triggered by winds.

Snowpack Summary

This soon-to-be formed storm interface will be very interesting to watch as our "storm" rolls through. Forecasters went out today to see what the current snow surface is like. What we saw from our limited trip was something to behold. As far as the surface goes, up to 2100m there's an exposed crust/wind skin/ice layer that isn't holding snow. Lots of loose dry sluffs today as winds moved the snow around. As for the mid pack and lower pack, the warm weather has helped create a hint of cohesiveness and support, but only a hint. We suspect that any loading won't be well received and a cycle will start.

Weather Summary

My achy knee tells me there's a storm a brewin'...

Forecasts agree that 7cm is expected by noon tomorrow. By tomorrow night there could be as much as 15cm!! Funny what qualifies as a storm these days. In other weather news, this is the beginning of another cold snap that will see temps in the -20 to -30 range by Saturday. Tomorrow, moderate winds will be gusty and coming at us from all directions until the cold air sinks in. -7 as a day time high tomorrow with cooling in the evening.

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.
Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

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.

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.