Avalanche Forecast

Issued: Dec 22nd, 2014 4:00PM

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

steve blagbrough, Parks Canada

Jasper.

The timing and intensity of this next system is a little uncertain. Any significant snow or wind event through the day on Tuesday could increase the hazard of slab avalanches on lee aspects at alpine and treeline elevations.

Summary

Weather Forecast

Heavy snowfall is forecast for the Columbia Icefields on Tuesday night accompanied by moderate to strong Westerly winds.

Snowpack Summary

Wind slab forming on lee alpine ridge lines. Large surface hoar crystals formed last week are being buried by new snow. This layer is more likely found on sheltered slopes at tree line reaching into the alpine. The interface between the strong mid-pack and weaker basal facets is most susceptible to human triggering from shallow rocky areas.

Avalanche Summary

No avalanches reported today.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Tuesday

Problems

Wind Slabs

Wind loading producing slabs on lee and cross loaded features predominately below alpine ridge lines.

Be careful with wind loaded pockets while approaching and climbing ice routes.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

This weak layer exists below a strong mid-pack at treeline and sub-alpine elevations. Field teams are still experiencing the occasional whumph from these weak layers collapsing.

Carefully evaluate and use caution around thin snowpack areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 23rd, 2014 4:00PM