Avalanche Forecast

Issued: Jan 20th, 2020 4:00PM

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

Avalanche Canada kdevine, Avalanche Canada

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Pockets of wind slab may be encountered at upper elevations. Use caution around wind loaded features.

Summary

Confidence

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

Weather Forecast

MONDAY NIGHT - Mainly cloudy with isolated flurries / south wind, 10-30 km/h / alpine low temperature near -3

TUESDAY - Flurries, 5-10 cm / south wind, 10-30 km/h / alpine high temperature near -2

WEDNESDAY - Cloudy with isolated flurries / southwest wind, 15-25 km/h / alpine high temperature near -4

THURSDAY - Flurries, 5-10 cm / southwest wind, 30-50 km/h / alpine high temperature near 0 / freezing level 1800 m

Avalanche Summary

Avalanche activity was pretty quiet on Sunday and Monday with one report of an explosives triggered size 2.5 loose snow avalanche.

On Thursday and Friday there were reports of numerous natural, human and explosives triggered size 1-2.5 storm and wind slab avalanches.

No new persistent slab avalanches were observed in the past few days, but this region has been highlighted for recent persistent slab avalanche activity. A number of natural and explosives triggered persistent slab avalanches up to size 3 were reported just over a week ago.

Snowpack Summary

Stormy weather over the past several days brought 35 to 65 cm of snow to the region with moderate to strong winds from a variety of directions. This, combined with recent warm temperatures, will have likely formed fresh storm slabs in many areas.

There are two weak layers of surface hoar found around 70 to 130 cm deep. These layers are especially concerning in steep, sheltered, large terrain features and shallow rocky areas.

The base of the snowpack is also weak in parts of the region where it consists of sugary faceted snow around a melt-freeze crust.

Terrain and Travel

  • Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.
  • Avoid freshly wind loaded terrain features.

Problems

Wind Slabs

An icon showing Wind Slabs

Previous new snow and wind has likely formed pockets of wind slab in lee terrain features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

Several persistent weak layers are buried in the snowpack. It is possible for humans to trigger them, or for smaller avalanches to step down to them and form very large avalanches. 

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Jan 21st, 2020 5:00PM