Avalanche Forecast

Issued: Feb 24th, 2018 4:00PM

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

jasper snow safety, Parks Canada

Jasper.

A firm slab, sitting over several persistent weak layers, can be found in isolated areas in the forecast region. Triggering it remains possible and would be a high consequence event.

Summary

Weather Forecast

Sunday will be cloudy and flurries, 4cm of snow, and -11 with light gusting moderate West winds. Monday will be clouds with sun and flurries, trace snow, -16 to -12 and light gusting strong West winds. Tuesday will be similar to Monday.

Snowpack Summary

Current and previous Strong W and N winds have left wind slabs and wind effect in open areas. The upper snowpack has settled to form a cohesive stiff slab that is sitting on three persistent weak layers mid-pack (down 50 to 80cm) which can be found throughout the forecast region, and have produced many large avalanches that have run full path.

Avalanche Summary

No patrol and nothing new reported Saturday. This past week we saw minimal natural activity yet it is still prudent to treat slopes that did not avalanche in the last cycle as suspect for human triggering.

Confidence

Timing or intensity of solar radiation is uncertain on Sunday

Problems

Persistent Slabs

A stiff slab 50 to 80cm thick, sits over sun Crusts (south and west aspects), Surface Hoar (at, and just above treeline) and weak Faceted Crystals (very developed in shallow snowpack features) This is a dangerous problem that is difficult to avoid.

Avoid shallow snowpack areas where triggering is more likely.Use conservative route selection, stick to supported terrain features, avoid overhead hazards.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3.5

Wind Slabs

Expect hardslabs in the alpine and a few softer slabs at treeline. The cold has kept these in check and helped them settle over the last few days but some caution is still warranted.

The best powder will be found in sheltered locations at or below treeline.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 25th, 2018 4:00PM