Avalanche Forecast

Issued: Dec 23rd, 2019 4:00PM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is considerable.

Avalanche Canada kdevine, Avalanche Canada

A deep persistent slab problem is the main concern in the Purcells. These avalanches can be difficult to predict, and they tend to be large and destructive. Stick to low angle terrain and avoid overhead exposure to avalanche terrain.

Summary

Confidence

Moderate - Uncertainty is due to the fact that deep persistent slabs are particularly difficult to forecast.

Weather Forecast

MONDAY NIGHT - Cloudy with clear periods and scattered flurries / southwest wind, 10-30 km/h / alpine low temperature near -8

TUESDAY - Mainly cloudy with isolated flurries / southwest wind 10-30 km/h / alpine high temperature near -8

WEDNESDAY - Cloudy with sunny periods / light northeast wind / alpine high temperature near -9

THURSDAY - Mainly sunny / light southwest wind, 20-40 km/h / alpine high temperature near -7

Avalanche Summary

A deep persistent weak layer in the snowpack has been responsible for some very large and destructive recent avalanches. The potential for very large avalanches still exists in the region.

On Sunday, there were numerous reports of natural and human triggered avalanches size 2-2.5 and explosives triggered avalanches up to size 4. A number of these avalanches were reported to have run on the deep persistent weak layer near the base of the snowpack.

Avalanche activity was widespread on Friday and Saturday with reports of natural, human and explosives triggered avalanches up to size 3.

Snowpack Summary

The Purcells received 60-120 cm of new snow since Thursday night. Storm slabs are likely widespread and are expected to continue to be reactive to human triggers.

There may be two layers of surface hoar buried between 70-180 cm. These layers likely exists mostly in sheltered areas at treeline and may be reactive to human triggers.

The base of the snowpack is generally quite weak and consists of a crust, facets and depth hoar. This deeper weakness in the snowpack has been responsible for numerous recent avalanches and remains a major concern in the region.

Terrain and Travel

  • Stick to simple terrain and be aware of what is above you at all times.
  • Avoid the runout zones of avalanche paths. Avalanches could run full path.
  • Storm slabs in motion may step down to deeply buried weak layers resulting in very large avalanches.

Valid until: Dec 24th, 2019 5:00PM