Avalanche Forecast

Issued: Apr 10th, 2023 4:00PM

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

Avalanche Canada bchristie, Avalanche Canada

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Observe your local conditions, and let that guide your terrain choice. Forecasted snow and rainfall amounts are uncertain.

As the freezing level falls, you will find that conditions change drastically with elevation and through the day.

Summary

Confidence

Low

Avalanche Summary

On Monday, in the Fernie area, widespread, naturally triggered, loose wet avalanches were reported. This included several large (size 2-2.5), avalanches, and even one large glide slab. Natural and human triggered avalanches will remain likely on Tuesday.

On Saturday, south of Fernie, a large (size 2), rider triggered avalanche was reported on a NE/E facing slope around treeline. The reporting riders kindly shared their close call on the Mountain Information Network (MIN). See the post here for more information and photos. Based on the direction the cornices have formed on the ridge above, it looks like the feature may have been cross-loaded by the wind. The reporting party said it appeared to trigger on a thin spot near some rocks, and that warm temperatures and sun may have been a factor.

If you head out in the backcountry, let us know what you are seeing by submitting a report to the Mountain Information Network.

Snowpack Summary

Moderate to heavy rain has soaked the surface snow to mountain tops in most places. As freezing levels drop, the alpine could have 10-25 cm of new snow on the surface.

The mid-snowpack is generally well-settled and strong.

At treeline and below, shallow snowpack areas are likely to be isothermal. Rain-soaked surfaces are starting to freeze as temperatures drop, and a lot more dirt is showing at low elevations.

The lower snowpack includes a layer of weak sugary crystals near the ground. This layer has not produced recent avalanche activity in this area, but professionals continue to monitor for signs of it becoming active.

Weather Summary

Snow/Rain amounts for the ongoing storm are uncertain. Weather models are not agreeing on how widespread or intense the precipitation will be, and exact freezing levels will be hard to forecast as they drop. Prepare to continually evaluate the conditions, and change plans as necessary.

Monday Night

Cloudy. 15-20 mm of rain around the Fernie area, 5-10 mm elsewhere, possible isolated areas of 35 mm. The rain/snow line may be as high as 3000 m, but should fall to 1700 m by the morning. Treeline high around 5°C. Moderate to strong southwest ridgetop wind, trending to extreme at high elevations.

Tuesday

Cloudy. The rain/snow line falls to 1000 m by the end of the day, resulting in 5-10 cm of snow through the day. Treeline low around -5°C. Moderate to strong southwest ridgetop wind.

Wednesday

Partly cloudy. 5-10 cm of snow expected. Treeline high around -5°C. Light southwest ridgetop wind.

Thursday

Partly cloudy. 0-5 cm of snow expected. Treeline high around -2°C. Light variable ridgetop wind.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Be alert to conditions that change with aspect and elevation.
  • Be alert to conditions that change throughout the day.
  • Watch for unstable snow on specific terrain features, especially when the snow is moist or wet.
  • The more the snow feels like a slurpy, the more likely loose wet avalanches will become.

Problems

Storm Slabs

An icon showing Storm Slabs

As freezing levels fall, it will start to snow in the alpine overnight, and into treeline as the storm tapers off on Tuesday.

Strong southwest winds at high elevations could be building deeper, more reactive pockets of slab in leeward terrain.

Use extra caution around ridgecrests, rolls, and on convex slopes. Retreat to mellower terrain if you find signs of instability like shooting cracks, whumpfs, or recent avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Loose Wet

An icon showing Loose Wet

A very wet storm has soaked the surface snow, and while freezing levels are falling, a loose wet avalanche problem may remain below treeline.

Watch for signs of loose wet instability, like snow pinwheeling or snowballing down the slope, or surface snow that starts to look and feel like a slurpy.

Aspects: All aspects.

Elevations: Below Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 11th, 2023 4:00PM