Avalanche Forecast

Issued: Mar 11th, 2023 4:00PM

The alpine rating is considerable, 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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6am update: Overnight snowfall has been highly variable throughout the region and is expected to continue through the day. Watch for reactivity in wind loaded features and be ready to step back into more conservative terrain if you're seeing more than 20 cm of new snow.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanche observations in the past 2 days. Avalanche activity is expected to increase with snowfall Saturday night and over Sunday. Natural avalanche activity is possible in areas that receive heavy snowfall and wind.

On Tuesday our field team observed several size 1-2 wind slab avalanches at Mt Cain which they estimated to be around 1-2 days old. Some of them failed down to the buried crust.

Snowpack Summary

Up to 30 cm of snow is likely by Sunday morning. This storm snow will sit over wind affected surfaces at upper elevations, and over a sun crust on sun affected slopes. Southerly winds are expected to build deeper deposits on north facing features.

A thick, widespread crust formed in mid February now sits 50-90 cm deep. Near Mt Cain, the crust is smooth with faceted crystals sitting on top of it. Avalanche activity on this layer has now tapered off, and reports show this interface is strengthening and unlikely to be triggered by a riders weight. Riders should still avoid thin and rocky start zones where this layer will sit closer to the surface.

The mid and lower snowpack is well consolidated, containing a series of well-bonded crusts.

Weather Summary

Saturday Night

Snowfall continues with up to 30 cm possible in the west and north. Snowfall amounts decrease as you move east, more likely to see 10-15cm. Freezing levels remain around 800 m. Moderate southerly wind.

Sunday

5-10 cm of new snow. Freezing levels reach 1000 m. Strong southwesterly wind. Alpine high -1 ˚C.

Monday

5 cm of new snow. Freezing levels reach 1000 m. Strong southwesterly wind. Alpine high -1 ˚C.

Tuesday

5 cm of new snow. Freezing levels reach 1000 m. Strong southwesterly wind. Alpine high -1 ˚C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Dial back your terrain choices if you are seeing more than 20 cm of new snow.
  • Watch for fresh storm slabs building throughout the day.
  • As the storm slab problem gets trickier, the easy solution is to choose more conservative terrain.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

Problems

Wind Slabs

An icon showing Wind Slabs

Storm snow will continue to accumulate over Sunday. Watch for deeper deposits in wind loaded terrain, and steer clear of open, steep slopes in areas that see greater than 20 cm. The bond between storm snow and the old snow surface (wind affect or sun crust) is expected to be poor.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 12th, 2023 5:00PM