Avalanche Forecast

Issued: Jan 5th, 2019 4:14PM

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

Deryl Kelly, Parks Canada

Jasper.

Storm snow will need some time to settle out. Localized slab development and analysis will be critically important for safe travel in the back-country. Enjoy!

Summary

Weather Forecast

Mainly cloudy with isolated flurries. Precipitation: Trace. Alpine temperature: High -5 °C. Ridge wind southwest: 20 km/h gusting to 45 km/h. Freezing level at valley bottom. A detailed mountain weather forecast is available from Avalanche Canada.

Snowpack Summary

Up to 45cm of snow has fallen along the 93N. Moderate-strong SW winds have built fresh wind slabs in open terrain and storm slabs in sheltered areas. The Dec. 11th layer (surface hoar and facets) persists down 60-150cm, and continues to produce avalanches in shallow snowpack areas.

Avalanche Summary

Helicopter control produced numerous smaller avalanches, and up to size 4 at Sunset Pass; burying the Icefields Parkway with significant debris and mature trees.

Confidence

Problems

Wind Slabs

Up to 45cm of fresh snow, warm temperatures and moderate to strong SW winds are creating widespread touchy windslabs and storm slabs.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Storm Slabs

Storm slab will become more dangerous and reactive as the whole snowpack settles into a stiffer slab.

The new snow will require several days to settle and stabilize.Minimize exposure during periods of loading from new snow and wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

The new snow has added to the load on the Dec 11th weak interface. Buried more than a meter deep in some locations, this layer is strengthening but has been reactive in shallow snowpack areas recently.

Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1.5 - 3.5

Valid until: Jan 6th, 2019 4:00PM