Avalanche Forecast

Issued: Mar 17th, 2022 4:00PM

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

Avalanche Canada rbuhler, Avalanche Canada

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Reactive wind slabs are expected to be the primary concern on Friday. However, if you are finding more than around 25 cm of new storm snow, a more widespread storm slab problem may develop. 

Summary

Confidence

Low - Uncertainty is due to the limited number of field observations. Forecast snowfall amounts are uncertain.

Weather Forecast

Thursday's storm system is forecast to linger through the overnight period. The next storm system is expected to arrive Friday night bringing snowfall through most of Saturday. 

Thursday night: Light snowfall 3-6 cm, light SW wind, freezing level around 1000 m. 

Friday: Mainly cloudy with sunny breaks in the afternoon, light SW wind, freezing level reaching around 1200 m. 

Friday night: Snowfall 10-20 cm, moderate to strong S wind, freezing level around 1200 m. 

Saturday: Snowfall 15-25 cm, moderate to strong SW wind, freezing level around 1000 m. 

Sunday: A mix of sun and cloud, light W wind, freezing level around 800 m. 

Avalanche Summary

On Wednesday, this MIN report described a small human-triggered avalanche failing in the top 10 cm. 

On Tuesday, a ski cut triggered a size 2 storm slab in the Sky Pilot area on a southwest aspect at 1600 m elevation which was 15-30 cm thick. In the North Shore area, ski cutting was triggering small loose wet avalanches. 

On Monday, natural storm slab activity up to size 2 was observed in the Sky Pilot area which was typically 20-30 cm thick. Around the North Shore, size 1 storm slabs were stubborn to trigger with explosives and ski cuts produced size 1 loose wet avalanches.

Snowpack Summary

Prior to Thursday's storm, 50-80 cm of heavy, moist storm snow which began accumulating last weekend appeared to be bonding well to the underlying hard melt-freeze crust which exists at all elevations and on all aspects except for high elevation north aspects. The snowpack is considered well-settled and strong below this crust. 

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid freshly wind loaded terrain features.
  • Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.

Problems

Wind Slabs

An icon showing Wind Slabs

The snowfall from Thursday is expected to have formed reactive wind slabs in exposed terrain features. 

There is uncertainty regarding how much new snow will have accumulated by the end of Thursday's storm. If you are finding more than around 25 cm of new snow, a more widespread storm slab problem may exist. 

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

Use extra caution on steep slopes at lower elevations where the recent storm snow is moist or wet. Human-triggered loose avalanches are possible, especially if the sun makes an appearance in the afternoon. 

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 18th, 2022 4:00PM