Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Dec 23rd, 2020–Dec 24th, 2020

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, human triggered possible.
Alpine
Below Threshold.
Treeline
Below Threshold.
Below Treeline
Below Threshold.

Regions

Kananaskis.

Cold snow and moderate winds demand users pay attention to changing conditions and choose conservative terrain. Give big features more time to settle before exposing yourself to them.

Confidence

Moderate -

Weather Forecast

Looks like a chilly night in front of us. About -20 tonight on the Spray, but a daytime high of -11 by 3pm. Nothing for snow and winds picking up during the day to about 50km/hr at treeline. Valley winds will be from the SW, while alpine winds will be NW.

Avalanche Summary

While doing the recon for an avalanche control run on EEOR, we noticed a widespread natural cycle mid to late storm. In talking with other people in the park, this cycle went on throughout the forecast region. Most avalanches were in the alpine, about sz 2 to 2.5 and seemed to involve only the storm snow. The EEOR paths themselves (alpine, E asp) had the Nov 5 crust as the failure plain for a couple of avalanches. We did have lots of sympathetically released slides today as well. This suggests the snow is slow to settle and is touchy.

Snowpack Summary

The storm snow has settled quickly and now sits at about 30cm in sheltered areas. Northern winds have taken a toll in open terrain and formed soft windslabs in many areas. The alpine has extensive wind affect at the moment. Alpine and treeline windslabs are now "layered" with slabs of varying vintages. We have seen evidence of avalanches within these layered wind slabs. The Deb 8th and Nov 5th layers are still out there and have reacted in many areas under the new load. We suspect its mostly the Dec 8 crust/facet layer that most guilty, but its also appeared that the Nov 5th has also been a culprit. See the Avalanche Summary for more details.

Terrain and Travel

  • Avoid steep convex slopes.
  • Back off steep and aggressive lines, stick to simple terrain.
  • Be cautious of sluffing.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.

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.