Avalanche Forecast

Issued: Apr 11th, 2023 4:00PM

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

Avalanche Canada jpercival, Avalanche Canada

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As the freezing level falls overnight and then warms during the afternoon, you will find that conditions change rapidly through the day. Be cognizant that daytime warming can rapidly destabilize the upper snowpack.

Prepare to continually evaluate the conditions, and change plans as necessary.

Summary

Confidence

Low

Avalanche Summary

On Monday and Tuesday, in the Fernie area. Warming and rain induced a widespread, naturally triggered, loose wet avalanche cycle. This included several large (size 2-2.5), avalanches and one large (size 2.5) glide slab.

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

Past moderate to heavy rain has saturated the surface snow to mountain tops in most places. Most weather reports indicate 20-30 mm of precipitation fell mostly in the form of rain.

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

Overnight cooling followed by afternoon rising freezing levels and warming is likely to unconsolidated and rapidly settle the upper snowpack especially on south aspect terrain when the sun appears. Prepare to continually evaluate the conditions, and change plans as necessary.

Tuesday Night

Clearing with cloudy periods. 1-5 cm of snow is possible in the alpine. Freezing level descending to 600m, Alpine temperature low of -7°C. Moderate southwest ridgetop wind.

Wednesday

Clear and sunny with possible trace amounts of snowfall. Freezing level rising to 1500m mid day. Alpine temperature high of -1. Light southwest wind.

Thursday

Clear and sunny with with possible trace amounts of snowfall. Freezing level rising to 1900m mid day. Alpine temperature high of 1°C. Light southwest wind.

Friday

Clear and sunny with no forecast precipitation. Freezing level rising to 1800m mid day. Alpine temperature high of 1°C. Light southwest 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

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 overnight are falling, a loose wet avalanche problem may remerge as daytime temperatures warm. Expect the upper snowpack to rapidly become unconsolidated when the sun appears even if it just for a brief period.

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: Treeline, Below Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Apr 12th, 2023 4:00PM