Avalanche Forecast

Issued: Apr 22nd, 2023 4:00PM

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

Avalanche Canada MH, Avalanche Canada

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A spring storm will bring snow to higher elevations and rain to lower elevations.

If you decide to trudge through the rain and sloppy snow to reach white-out conditions in the alpine, evaluate changing conditions as you gain elevation or change aspects.

Summary

Confidence

Moderate

Avalanche Summary

Expect avalanche activity to increase on Sunday as lower elevations get saturated by rain and higher elevations receive 10-15cm of snow and moderate winds.

No new avalanches were observed or reported for the last two days.

Snowpack Summary

Below treeline, the snowpack is a series of supportive crusts, which break down with daytime warming.

At treeline and in the alpine, North aspects still hold dry snow. On solar aspects, a breakable crust overlies a series of buried crusts, which may provide a failure plane for slab avalanches as temps rise.

The Nov 17 basal weakness can still be found in many locations 20-40cm thick, above the ground.

Weather Summary

A storm system slides into the region Saturday evening bringing 10-15cm of snow at higher elevations and rain below tree line. Winds will be 20-40km/hr from the SW with a freezing level of 2000m.

Another 5cm on Monday with light winds.

Terrain and Travel Advice

  • Storm slab size and sensitivity to triggering will likely increase through the day.
  • The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.
  • Avoid terrain traps such as gullies and cliffs where the consequence of any avalanche could be serious.
  • The more the snow feels like a slurpy, the more likely loose wet avalanches will become.
  • If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

10-15cm of snow will fall at higher elevations and will be deeper in wind loaded areas. On solar aspects it will fall onto a crust and may be quite reactive until it has time to bond. Evaluate changing conditions if you gain elevation or change aspects.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

Up to 60cm of settled snow covers a series of crusts combined with surface hoar/facets in some locations. Loose wet avalanches in motion have the potential to step down to these layers, creating large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 3

Loose Wet

An icon showing Loose Wet

Lower elevations will see 10mm of rain, as the freezing level rises up to 2000m. The snowpack below tree line will lose strength and wet loose avalanches will become likely in steep terrain.

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

Elevations: Treeline, Below Treeline.

Likelihood

Likely

Expected Size

1 - 2.5

Valid until: Apr 23rd, 2023 4:00PM

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