Avalanche Forecast

Issued: Dec 27th, 2020 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Persistent Slabs.

mark herbison,

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The snowpack is complex and has a great deal of variability throughout the region. Assess the snowpack locally before committing to your line and consider what looms overhead if climbing in exposed terrain.

Happy Holidays!

Summary

Weather Forecast

Monday will see a mix of sun and cloud with isolated flurries accumulating 1-2 cm of snow. Temps will range from -6 to -13 as the winds will remain light,10-25 km/hr from the West. Sunny with light winds for Tuesday.

Snowpack Summary

Small amounts of new snow now bury wind slabs created by recent 25-45km/hr SW-W winds redistributing the 30-60cm of snow from the past week. The Dec 13 and Dec 7 sun crust/surface hoar/facet layers are down ~ 50cm and ~80 cm respectively. The decomposing Nov crust/facets sits at the bottom of the snowpack. Height of snow at tree line is 120-170cm.

Avalanche Summary

No new natural avalanche activity observed or reported. A skier triggered size 1.0 was reported in the Hamilton Lakes area, 25cm deep, 3m wide, triggered on a steep convex roll.

Local ski areas reporting small, thin wind slabs on NE aspects, triggered by explosives.

Confidence

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs were formed by strong SW-W winds Wednesday through Friday. While these are now buried with new snow, expect to find small, spotty slabs as you enter open areas at Tree Line and into the Alpine.

  • Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.
  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

There are a variety of weaker layers down ~50-80cm. These are the Dec 7 and 13th layers of facets, suncrust, and isolated surface hoar. These layers deserve constant suspicion, they can change quickly from one aspect to another.

  • Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Dec 28th, 2020 4:00PM