Avalanche Forecast

Issued: Dec 1st, 2020 4:00PM

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

Avalanche Canada JSmith, Avalanche Canada

  

Things are looking HOT up high for the next couple days. Naturally triggered wet loose avalanches are possible on all aspects and especially likely on solar aspects. Overhead hazards will be a primary concern.

Summary

Confidence

Low - Uncertainty is due to the limited number of field observations.

Weather Forecast

  

TUESDAY NIGHT: Clear / Light, northwest ridgetop wind / alpine low temperature 0 (temperature inversion, -12 in valleys) / Strong temperature inversion with above freezing air 2000-3500 m.

WEDNESDAY: Sunny / Light, southwest ridgetop wind / alpine high temperature +4 / Strong temperature inversion with above freezing air 2000-3500 m.

THURSDAY: Sunny / Light, southwest ridgetop wind / alpine high temperature +4 / Strong temperature inversion with above freezing air 2000-3500 m.

FRIDAY: Mix of sun and cloud / Light, northeast ridgetop wind / alpine high temperature 0 / Temperature inversion with above freezing air 2000-3000 m.

Avalanche Summary

Check out this notable MIN report of numerous human triggered avalanches from Quartz Creek on Saturday. The buried layer of small surface hoar that caused this avalanche could still catch riders by surprise.

Data is very sparse in this region. Please submit your observations to the Mountain Information Network.

Snowpack Summary

  

  

Around 5 cm of new snow on Monday has covered a layer of surface hoar found primarily at treeline and below. The strong southwest winds from last week created wind slabs on lee features at treeline and above. These wind slabs are sitting on a layer of small surface hoar in specific areas. This layer has been reported as "spotty" and is most likely to be present in sheltered areas. There is a crust from early November that is down approximately 50-75 cm. This layer has been observed to have weak, sugary facets above and below it. It is most likely to be reactive to human triggers on south facing slopes and in shallow, rocky, snowpack areas in the alpine.

Terrain and Travel

  • Avoid exposure to overhead hazards when solar radiation is strong.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.
  • If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The hot weather up high over the next couple days may awaken this layer. Cornice falls, or smaller avalanches are especially likely to trigger a large avalanche on this layer. This layer is most likely to be reactive to human triggers on south facing slopes and in shallow, rocky, snowpack areas in the alpine.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Loose Wet

An icon showing Loose Wet

Things are looking HOT up high for the next couple days. Naturally triggered wet loose avalanches are possible on all aspects and especially likely on solar aspects.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 1.5

Wind Slabs

An icon showing Wind Slabs

Lingering wind slabs may remain surprisingly reactive to human triggers in areas where they are sitting on top of a layer of small surface hoar.

Aspects: North, North East, East, South East, South, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 2nd, 2020 4:00PM