Avalanche Forecast

Issued: Apr 22nd, 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, Loose Wet and Deep Persistent Slabs.

Avalanche Canada istorm, Avalanche Canada

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It's a challenge to manage different avalanche concerns that vary by elevation and aspect. Observe local conditions and use that information to help select terrain and travel techniques. Temperatures are rising and warm temperatures melt the strength out of the snow so avoid avalanche terrain if the sun pops out, during periods of heavy snow or rain, or if you observe (recent) avalanche activity.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches reported. Previous reports were of solar triggered avalanches up to size 2.5 in the afternoon. Please remember there are few eyes still out there regularly reporting field observations.

Snowpack Summary

Continued light amounts of snow fell at higher elevations and on north-facing slopes as low as treeline. This recent snow is settling and bonding about as fast as more arrives. Windslabs are possible in immediate lee features.

On solar aspects at all elevations, and north aspects at treeline and low elevations, the recent snow either overlies a widespread melt-freeze crust or there is a crust at the surface. Watch for surface snow becoming moist in the afternoon.

The middle of the snowpack is generally well-settled and strong. A weak layer of facets at the base of the snowpack remains a concern, primarily in alpine terrain with shallow or variable (thick and thin) snowpack depths but also where there's overhead hazard (for example from cornices).

Weather Summary

Saturday Overnight

Cloudy with flurries. Just a trace to 5 cm of snow. Moderate southwest ridgetop winds. Treeline temperatures around -5 C. Freezing level around 1500 m.

Sunday

Cloudy with snow. Accumulations by the end of the day around 10 - 15 cm but as high as 25 cm. Moderate southerly winds. Treeline temperatures around zero and freezing level around 2000 to 2200 m.

Monday

Warm overnight temperatures with freezing level remaining around 2000m. Overnight another 5 to 10 cm of snow by Monday morning. Wind diminishing to light. Treeline temperatures around -3 and freezing level around 2000 m.

Tuesday

A mix of sun and cloud. Nil precipitation. Wind moderate to strong from the west. Around -5 C at treeline with freezing level around 1700 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
  • Be alert to conditions that change with elevation and sun exposure.
  • Shooting cracks, whumphs and recent avalanches are strong indicators of an unstable snowpack.
  • Be carefull around freshly wind loaded features.
  • Investigate the bond of the recent snow before committing to your line.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.

Problems

Storm Slabs

An icon showing Storm Slabs

New storm slabs are possible at high elevations. Dial back your terrain choices if you encounter more than 20 to 30 cm of new snow. Watch for this snow sitting on a slippery crust on solar aspects. Watch for wind slabs on lee features, primarily at higher elevations where dry snow persists.

Aspects: All aspects.

Elevations: Alpine, Treeline.

JavaScript chart by amCharts 3.20.8

Likelihood

Likely

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

Warm temperatures, including little overnight freeze, and wet snow or rain could trigger sliding in the recent snow on slippery crusts and at low elevations.

Aspects: All aspects.

Elevations: All elevations.

JavaScript chart by amCharts 3.20.8

Likelihood

Possible

Expected Size

1.5 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

A weak layer of facets exists near the base of the snowpack. Thinner snowpack areas and areas with variable thick and thin coverage at alpine elevations is where this problem is most likely found. April's warming temperatures may gradually increase the sensitivity of this layer, especially in thin snowpack areas.

Aspects: All aspects.

Elevations: Alpine.

JavaScript chart by amCharts 3.20.8

Likelihood

Unlikely

Expected Size

2.5 - 4

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

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