Avalanche Forecast

Issued: Apr 21st, 2023 4:00PM

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

Avalanche Canada JH, Avalanche Canada

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Temps are gradually rising, but clouds are forecast to continue to roll in overnight.

Scale back your exposure if the sun pops out unexpectedly.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches were observed or reported on Friday.

On Thursday, sun and warm temps triggered a cycle of loose wet avalanches, up to size 2.5, in steep solar terrain. There was also an MCR report of a size 2.5 remotely triggered avalanche from a solar aspect in the alpine.

Snowpack Summary

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

At treeline and in the alpine, steep due N aspects still hold dry snow. On solar aspects a breakable surface 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

Increasingly unsettled weather and warming temps in to the weekend, as a pacific low approaches.

Tonight: Alpine low -5°C, light W ridge winds.

Sat: Isolated flurries, High -2°C, Freezing level (FZL) 1900m, Light SW wind.

Sun: Periods of snow/rain (10-15cm). Low -1°C, High 1°C. FZL 2200m. Light SW wind.

Mon: Isolated flurries. Low -4°C, High -1°C. FZL 2000m.

Terrain and Travel Advice

  • Rocks will heat up with daytime warming and may become trigger points for loose wet avalanches
  • 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.

Problems

Loose Wet

An icon showing Loose Wet

As the day warms, moist/wet surface snow will slide on the most recent crust, and could gain mass in steep open terrain.

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

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Persistent Slabs

An icon showing Persistent Slabs

Snow that fell in the past 2 weeks 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

Unlikely - Possible

Expected Size

1.5 - 2.5

Valid until: Apr 22nd, 2023 8:00PM