Avalanche Forecast

Issued: Apr 10th, 2023 4:00PM

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

Avalanche Canada bchristie, Avalanche Canada

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Give the weather another day to calm down before exploring the alpine.

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

Summary

Confidence

Moderate

Avalanche Summary

On Monday in neighboring Waterton National Park, numerous loose wet avalanches up to size 2.5 were reported on all aspects and elevations during the warm, wet storm.

If you have any observations from this region, let us know what you are seeing by submitting a report to the Mountain Information Network.

Snowpack Summary

In the alpine and around treeline, 5-10 cm of new snow covers rain soaked surfaces. Prior to the weekend storm, dry snow only remained on shaded (northerly) slopes.

The mid snowpack is generally settled and strong at treeline and above.

A melt-freeze crust that was buried in mid January can be found 60 to 100 cm below the snow surface.

A weak layer of large, sugary crystals persists at the base of the snowpack. 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 with a possible clear period around midnight. Light to moderate rainfall expected. 5 mm with isolated areas of 15 mm or more. Snow/rain line rising to 3000 m, falling back below 2500 m by morning. Moderate southwest ridgetop wind, trending to extreme at high elevations.

Tuesday

Cloudy. 5-10 cm of snow expected. Snow/rain line starts the morning around 2000 m and falls to valley bottom through the day. Treeline low around -4°C. Moderate southwest ridgetop wind, trending to strong at high elevations.

Wednesday

Partly cloudy. Possible trace of snow expected. Treeline high around -4°C. Light southwest ridgetop wind.

Thursday

Mostly cloudy. 5 cm of snow expected. Treeline high around -4°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 could start to snow in the alpine overnight, and even below treeline as the storm tapers off on Tuesday.

Strong southwest alpine wind could be stripping ridges down to rock, or rapidly loading 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 - 2

Loose Wet

An icon showing Loose Wet

With moderate rainfall up to 2500 m, loose wet avalanches will remain likely in the morning. As the freezing level drops through the day on Tuesday, the surface will start to freeze and stability will improve.

Watch for signs of a loose, wet snowpack, like snow pinwheeling or snowballing down the slope, or surface snow that looks and feels like a slurpy.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

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