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 12th, 2022–Dec 13th, 2022

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
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.

Regions

South Rockies, Bull, Crowsnest North, Crowsnest South, Elkford East, Elkford West.

Expect differing avalanche problems depending on where in our region you recreate today.

Wind slabs are the main concern in the eastern regions while a buried weak layer needs your attention in the west and central regions.

Plan your travel and terrain choices appropriately. Read our latest blog for ways of managing our avalanche problem.

Confidence

Moderate

Avalanche Summary

Over the last few days, there has been an increase in avalanche activity in our region and in that of our nearest neighbours. Local operators have been able to trigger wind slabs and buried weak layers with the use of explosives producing large avalanches. There have been reports in the MIN of people accidentally triggering avalanches. Other signs of instability are being reported as well, such as seeing debris from avalanche, experiencing whumpfs and shooting cracks. Some MIN reports have witnessed lots of reactivity on the buried weak layer, 60 cm deep, in snowpack testing. Avalanches are failing mostly on the buried weak layer but wind slabs were also reactive. There was also an avalanche involvement to the immediate west of us that occurred from triggering the weak layer.

Snowpack Summary

Since Thursday night up to 20 cm has accumulated in some parts of our region. Much of this has been redistributed by strong westerly winds at most elevations. The new snow and new wind slabs are covering a variety of surfaces which will need time to bond properly. It is expected that the wind has built wind slabs upon wind slabs in some areas while in other areas the wind will have stripped away the majority of the snow.

Where the wind had less of an impact on the snow you can expect to find around 10 to 20 cm of soft snow sitting on 30 to 40 cm of more settled snow. Buried 45 to 65 cm down lies a weak layer comprising of surface hoar and facets. This layer has been shown to be reactive in snowpack tests and showed be kept on your radar for the time being. Further down the snow is sugary and faceted with a rain crust near the ground but this lower snowpack appears to be consolidating.

Total snowpack depths at treeline elevations are 75 to 155 cm.

Weather Summary

Monday Night

Clear clouds increasing, no accumulation, winds northeast 10 km/h, temperature -10 C at 1500 m.

Tuesday

Mostly cloudy, trace accumulation, winds west 10 km/h, temperature -8 C at 1500 m.

Wednesday

Cloudy with possible sunny periods, up to 3 cm accumulation in some places, winds southwest 10 km/h, temperature -8 C at 1500 m.

Thursday

A mix of sun and cloud, trace accumulation, winds northeast 10 gusting to 25 km/h, temperature -10 C at 1500 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Caution around convexities or sharp changes in terrain.

Problems

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.