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 26th, 2021–Dec 27th, 2021

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

Regions

South Coast.

Northerly outflow winds are creating reactive wind slabs in unusual patterns. Keep in mind that cold temperatures can increase the consequences of an incident. Start simple, gather information as you go, and seek out softer conditions in wind-sheltered areas. 

Confidence

Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.

Weather Forecast

Cold, Arctic air and north winds take the reins

Sunday night: Partly cloudy, no new snow expected, light northeast winds, treeline low temperatures near -16 C, freezing level at sea level.

Monday: Increasing cloudiness, no new snow expected, winds becoming northwest and increasing to moderate, treeline high temperatures near -12 C, freezing level at sea level.

Tuesday: Mainly clear, a trace of new snow possible overnight, moderate northwest winds, treeline high temperatures near -8 C, freezing level at sea level. 

Wednesday: Mix of sun and cloud, no new snow expected, moderate northwest winds, treeline high temperatures near -8 C, freezing level at sea level.

Avalanche Summary

It remains possible to trigger to avalanches where the recent snow has been drifted into reactive slabs, especially near ridge crests and roll-overs. 

On Sunday, backcountry travelers near Brockton Point reported a small pocket releasing in the storm snow on a steep terrain feature. On Saturday, operators reported small (size 1) soft slabs releasing in the storm snow from ski cuts that ran fast and far on a rain crust. 

On Friday, we received several reports of touchy conditions in the North Shore Mountains. Check out these MIN reports from Hollyburn, Pump Peak, Brockton Point and Brockton Point for great descriptions and photos of the conditions. 

Snowpack Summary

Since Friday, 25-40 cm of snow has fallen a variety of previous snow surfaces, including preserved powder and wind-packed snow at upper elevations and a rain crust near and below treeline. 

Moderate to strong outflow winds at all elevations have had an ample supply of light, cold snow to drift into reactive slabs. Watch for unusual cross-loading or reverse-loading patterns in wind-exposed areas, and anticipate reactive wind slabs on a variety of aspects and potentially at lower elevations. Sensitivity to triggering will be greatest near ridge crests and roll-overs. Monitor for changing slab conditions as you move into wind-exposed terrain. 

In the north of the region, a concerning layer of facets (sugary snow) can be found down 100-200cm over a crust that formed in early December. This layer is slowly transitioning from stubborn to unreactive as the snow above stiffens and makes it harder to trigger. This problem is particularly hard to predict and tricky to manage. Get more details and photos in our forecaster blog, and be sure to watch this week's snowpack summary video from North Shore Rescue. 

Terrain and Travel

  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Keep your guard up at lower elevations. Wind slab formation has been extensive.
  • Make observations and assess conditions continually as you travel.

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.