Avalanche Forecast

Issued: Jan 28th, 2021 4:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

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Recent flurries likely formed small pockets of wind slab in the immediate lee of ridges and exposed terrain features. Danger ratings in the south of the province show where we're headed once our latest weak layer gets buried a bit deeper.

Summary

Confidence

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

Weather Forecast

Thursday night: Cloudy with isolated flurries and a trace of new snow. Light southwest winds.

Friday: Mainly cloudy with isolated flurries and a trace of new snow. Light southwest winds, increasing overnight. Alpine high temperatures around -12. 

Saturday: Cloudy with isolated flurries and a trace of new snow, continuing overnight. Moderate to strong south winds, increasing over the day and staying elevated overnight. Alpine high temperatures around -9.

Sunday: Cloudy with continuing scattered flurries bringing about 5 cm of new snow, increasing a bit overnight. Strong south or southeast winds. Alpine high temperatures around -7.

Avalanche Summary

There have been no recent avalanche reports in the region. 

We're continuing to track a layer of surface hoar from early January which has been trending towards unreactive. The most recent activity reported on this layer comes from January 16, when professional operators reported a small (size 1) avalanche releasing 40 cm deep. 

Recent observations from the north Blue River Valley describe this layer reacting to skier traffic on steep, unsupported features below treeline. This and snowpack tests that continue to sporadically produce easier, more sudden snowpack results make this layer worthy of continued monitoring.

Snowpack Summary

Up to about 15 cm of new low density snow has buried a weak layer of surface hoar that is widespread in the region. The surface hoar grew on variable surfaces that include scoured and pressed surfaces in exposed terrain as well as faceted snow in more sheltered terrain. A thin sun crust may be found on steep solar aspects. Below 1600 m, 30-40 cm of snow is settling above a decomposing melt freeze crust. 

A weak of layer of surface hoar from early January can now be found buried 40-70 cm deep. This layer last demonstrated reactivity over a week ago (Jan 16) in the south of the region near Valemount. It is most suspect in sheltered, open slopes at and below treeline. Although results from recent snowpack tests show increasingly resistant results (check out this MIN from near Barkerville), slope-specific assessment is warranted. 

Deeper in the snowpack, a couple of older persistent weak layers may still be identifiable from late and early December, consisting of surface hoar and a crust with faceted snow and buried anywhere from 70-150 cm deep. Prolonged periods of inactivity and unreactive snowpack test results suggest that these layers have trended towards dormancy. 

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent flurries likely resulted in small new wind slabs forming in leeward pockets at ridgecrests and around exposed terrain features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Jan 29th, 2021 4:00PM