Avalanche Forecast

Issued: Dec 29th, 2020 4:00PM

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

kdevine, Avalanche Canada

South Coast.

A big storm is expected to bring up to 50 cm of new snow by Wednesday evening. Avoid avalanche terrain for now, as a widespread avalanche cycle is expected.

Summary

Confidence

Moderate - Uncertainty is due to difficult to forecast freezing levels.

Weather Forecast

TUESDAY NIGHT - Snow, 10-20 cm / southwest wind, 30-60 km/h, gusting to 80 km/h / alpine low temperature near -2

WEDNESDAY - Snow, mixed with rain at times, 25-30 cm / southwest wind, 40-60 km/h, gusting to 80 km/h / alpine high temperature near 0 / freezing level rising to 1000 m

THURSDAY - Mainly cloudy / light northwest winds / alpine high temperature near 0 / freezing level 1200 m

FRIDAY - Snow and rain, 30-50 cm / southwest wind, 60-80 km/h / alpine high temperature near 1 / freezing level 1500 m

Avalanche Summary

Stormy weather overnight Tuesday and into Wednesday will likely result in a natural avalanche cycle. Steer clear of avalanche terrain for now.

Snowpack Summary

10-20 cm overnight Tuesday followed by up to 30 cm on Wednesday will mean that storm slabs will be widespread, and easy to trigger.

This new snow will land on 30-70 cm recent storm snow which appears to be adhering well to old surfaces.

Around 80-130 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 all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
The more the snow feels like a slurpy, the more likely loose wet avalanches will become.

Problems

Storm Slabs

There may be up to 50 cm of new snow by Wednesday afternoon, likely resulting in widespread storm slab avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2

Loose Wet

Wet snow, possibly mixed with rain at lower elevations may result in wet loose avalanches.

Aspects: All aspects.

Elevations: Below Treeline.

Likelihood

Likely

Expected Size

1 - 1.5

Valid until: Dec 30th, 2020 4:00PM