Avalanche Forecast

Issued: Mar 14th, 2022 4:00PM

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

Avalanche Canada wlewis, Avalanche Canada

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Wind continues to be the main driver of avalanche hazard. Watch for south/west winds loading sheltered open slopes at treeline and in the low alpine; buried surface hoar may be present, increasing avalanche size and reactivity. 

Summary

Confidence

Moderate - Uncertainty is due to the complexity of the snowpack’s structure.

Weather Forecast

MONDAY: Another 5 cm possible overnight. Moderate southwest winds. Freezing levels around 1000 m.

TUESDAY: Scattered flurries continue with moderate to strong southwest winds. A mix of sun and cloud. Freezing level around 1000 m, alpine high of -2. 

WEDNESDAY: 5 cm of snow overnight. Isolated flurries over the day with moderate southwest winds. Partly cloudy. Freezing levels 1000 m. Alpine high -2. 

THURSDAY: Flurries continue with strong southwest winds. Partly cloudy. Freezing levels around 1000 m. 

Avalanche Summary

Human triggered wind slab activity continued on Sunday, to size 1 in wind loaded features. Sluffing was observed out of steep and sheltered terrain features. 

The late February surface hoar has shown reactivity in recent snowpack tests, and avalanche activity over the last 3 days. A remote size 1.5 was triggered on a northeast aspect at 1450 m. A MIN report describes a size 2 slab avalanche triggered by a snowmobile on a southeast facing alpine slope from Saturday. This layer is most likely to be triggered where winds are loading sheltered open slopes at treeline. 

Snowpack Summary

10-20 cm of storm snow has likely been redistributed into wind loaded pockets by strong southwest winds. 

Around 30-40 cm deep, a surface hoar layer buried in late February is preserved in wind sheltered features at treeline and low alpine elevations. On sun affected aspects, this interface exists as a crust. This layer has shown to be reactive in snowpack tests and recent avalanche observations. 

The thick mid-February crust is now buried 50-70 cm deep. These layers are unlikely to be human triggered, but possible to trigger with very large loads such as avalanches in motion or cornice falls.

The lower snowpack is well protected by the mid-February crust, and triggering avalanches below this layer is unlikely at this time. 

Terrain and Travel

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Wind slabs are most reactive during their formation.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

Expect most wind loading to be found on east facing slopes (lee to west/southwest winds).

Wind loading may sit over a crust on south facing slopes, or a buried surface hoar in sheltered treeline terrain. Likelihood of human triggering is higher in these features. 

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 15th, 2022 4:00PM