Avalanche Forecast

Issued: Apr 7th, 2014 4:00PM

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

garth lemke, Parks Canada

Jasper.

Monitor the winds and snow amounts Tuesday evening. If they exceed expectations, it has potential to tip the scales increasing the danger with direct action avalanches. Models are not agreeing thus the uncertainty for Wednesday.

Summary

Weather Forecast

Tuesday will be cloudy and potentially moderate to strong winds starting in a.m. with a pulse of snow beginning at noon into Wednesday. Models range from 10-30cm for Icefields, 8-12 for Marmot, and 4-8 for Maligne. Some of this may start as rain. Tuesday's freezing level will hover around 2000m then drop to 1500-1700m with a cooling trend Wed.

Snowpack Summary

SW winds forming windslab along alpine ridge tops. A temperature crust is found on lower elevation slopes and southerly slopes into the alpine. Windslab developing on this slippery surface should be assessed. Weak basal facets appears to be bridged, requires a large trigger, or a tickle in just the right spot, and would be a large avalanche.

Avalanche Summary

No avalanches reported today.

Confidence

Intensity of incoming weather systems is uncertain on Tuesday

Problems

Wind Slabs

Windslabs have developed along ridgelines and crossloaded features. Their thickness and interface is variable depending on aspect, elevation, and localized weather influences. Incoming winds and snow Tuesday afternoon will add to this condition.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Use caution in lee areas. Recent wind loading have created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Deep Persistent Slabs

The deep nature of this weakness is difficult to predict and would have severe consequences if triggered. A lot of spatial variability exists. Field team reports large tree shaking whumph Sunday, E aspect, at 1800m.

Avoid shallow snowpack areas where triggering is more likely.Conditions are greatly improved, but be mindful that deep instabilities are still present.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 8th, 2014 4:00PM