Avalanche Forecast

Issued: Dec 23rd, 2014 4:00PM

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

Parks Canada steve blagbrough, Parks Canada

A moist pacific weather system will generate significant snowfall amounts through Tuesday night into Wednesday morning at higher elevations.

Summary

Weather Forecast

Heavy snowfall warning in effect for the high mountain passes on Tuesday night with 15-20cm accompanied by strong South 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 to be found on sheltered slopes at tree line and below 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 observed today.

Confidence

Intensity of incoming weather systems is uncertain on Wednesday

Problems

Wind Slabs

An icon showing Wind Slabs
Wind loading producing slabs on lee and cross loaded features at all elevations. Field teams today experienced cracking and whumphing in the new wind slab.
Be cautious as you transition into wind affected terrain.Be careful with wind loaded pockets while approaching and climbing ice routes.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing 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 this layer. Surface slides or cornice collapse could trigger this deep persistent weakness.
Carefully evaluate and use caution around thin snowpack areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 24th, 2014 4:00PM