Avalanche Forecast

Issued: Dec 27th, 2020 4:00PM

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

Avalanche Canada ahanna, Avalanche Canada

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New snow is especially sensitive to seeing the sun for the first time. On Monday afternoon you may observe increased reactivity of storm slabs to human triggers as well as solar triggered point releases on steep south facing slopes.

Summary

Confidence

Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.

Weather Forecast

Sunday night: Clearing, light southwest wind, freezing level rising to 1500 m.

Monday: Sunny, light northwest wind, treeline temperature 0 C, freezing level 1600 m.

Tuesday: Increasing cloud, moderate southwest wind, treeline temperature -3 C, freezing level 800 m.

Wednesday: Cloudy, moderate southwest wind, treeline temperature -3 C, freezing level 800 m.

Avalanche Summary

On Saturday, we received reports from the North Shore mountains of several skier controlled wet loose size 1 and a skier remote size 1 wet slab on a steep unsupported roll. Some whumphing was observed but very little propagation within the storm snow.

We know you're out there! Please share your observations with us on the Mountain Information Network (MIN)! Photos are especially helpful. Thanks for all the great MINs submitted so far.

Snowpack Summary

30-70 cm of recent snow appears to be adhering well to old surfaces. At higher elevations where dry snow fell, strong winds are expected to have deposited deep pockets of storm slab into lee terrain features.

Around 50-100 cm of snow now overlies a hard melt-freeze crust up to around 1500 m. This layer varies so widely in depth due to the wind transport of snow as it fell over the last two storms. It seems to be bonding well with surrounding snow.

The remainder of the snowpack is well-settled and hosts numerous other melt-freeze crusts which are well bonded to the surrounding snow.

Terrain and Travel

  • Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Problems

Loose Wet

An icon showing Loose Wet

With warming temperatures and sun exposure, we can expect to see loose wet avalanches in the new snow, especially on steep south to southwest facing slopes and at elevations where temperatures rise above freezing.

Aspects: South East, South, South West.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Storm Slabs

An icon showing Storm Slabs

30-50 cm of recent snow has been redistributed at upper elevations by overnight wind from the southwest. Recent snow may become increasingly sensitive to triggering when touched by the sun for the first time.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 28th, 2020 4:00PM