Avalanche Forecast

Issued: Jan 28th, 2021 4:00PM

The alpine rating is moderate, 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 neighbouring South Columbias show where we're headed once our latest weak layer gets buried a bit deeper. 

Summary

Confidence

High -

Weather Forecast

Thursday night: Cloudy with easing flurries and up to 5 cm of new snow. Light southwest winds.

Friday: Mainly cloudy. Light southwest winds. Alpine high temperatures around -11.

Saturday: Cloudy with isolated flurries and a trace of new snow, increasing a bit overnight. Light to moderate variable southeast to southwest winds, increasing over the day and overnight. Alpine high temperatures around -9.

Sunday: Cloudy with continuing scattered flurries bringing about 5 cm of new snow. Light to moderate south or southeast winds, potentially strong (south) in the alpine. Alpine high temperatures around -7.

Avalanche Summary

We're just beginning to receive reports of newly formed small (size 1) wind slabs releasing with skier traffic as a result of recent flurry and wind activity. Loose dry sluffing of our new snow in steep terrain has been more widely reported. 

We're continuing to track a layer of surface hoar from early January, the most recent activity reported on this layer was January 17 from Clemina Creek documenting cracking and propagation in sheltered treeline and below treeline areas on surface hoar buried 40-50 cm deep. Although it has followed a trend toward being unreactive, this layer continues to sporadically produce easier, more sudden snowpack test results that make it worthy of continued monitoring.

Snowpack Summary

Up to about 15 cm of new low density snow has covered a widespread layer of weak surface hoar that has grown up to 15 mm in some areas. This surface hoar grew on a variety of surfaces that include heavily wind affected surfaces in exposed terrain as well as more variable wind affected and faceted snow in sheltered spots. A thin sun crust may be found on steep solar aspects. Below 1600 m, 20-30 cm of snow is settling above a decomposing melt freeze crust. 

Observers continue to find a preserved layer of surface hoar down 40-80 cm in sheltered, open slopes at and below treeline. Recent snowpack tests have produced sudden results on this layer, other tests have found it unreactive, as such it continues to warrant slope-specific assessment. 

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 100-200 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 have resulted in 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