Avalanche Forecast

Issued: Dec 26th, 2020 4:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs, Loose Dry and Deep Persistent Slabs.

Garth Lemke,

Jasper.

Enjoy the holidays, but be mindful that you may find variable wind slabs in the alpine and open tree line.

Summary

Weather Forecast

Sunday will be cloudy and flurries, trace amount of snow, -9C and light SW winds. Monday will be sun and cloud with a trace of new snow, -14C and light West winds. Tuesday will be similar with no new snow.

Snowpack Summary

There is 15-30cm of soft snow or dense wind-slabs location dependent over a generally firm mid-pack. Mid-pack crusts on steep solar aspects may be encountered at tree-line and below. An early season crust is down 40-100cm and decomposing. It overlies weak basal facets and depth hoar but is well bridged by the mid-pack above unless shallow location.

Avalanche Summary

Patrol to Churchill slide path today noted no new activity but visibility was poor.

Confidence

The weather pattern is stable

Problems

Wind Slabs

Winds in the alpine and open tree line locations continue to develop wind slabs. Caution as these wind slabs appear to be stubborn, are localized, and are suspect to be susceptible to human triggering particularly high alpine ridgetop features.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Be careful with reverse loaded pockets of wind slab at ridgeline.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Loose Dry

Facetted surface snow can quickly gain significant mass particularly in steep alpine gullies.

Minimize exposure to terrain traps where the consequences of an avalanche could be serious.
Be cautious of sluffing in steep terrain, particularly where the debris flows into terrain traps.

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

Elevations: Treeline, Below Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Deep Persistent Slabs

Be cautious of thick to thin snowpack areas being likely trigger locations. The wind slabs have the potential to step down to the weakness at the base of the snowpack.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Use caution in thin snowpack areas.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Dec 27th, 2020 4:00PM