Avalanche Forecast

Issued: Jan 4th, 2019 4:17PM

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

deryl kelly, Parks Canada

Jasper.

Heavy, wet and dense snow throughout the forecast region. Check Alberta 511 for highways updates.

Summary

Weather Forecast

Cloudy with sunny periods. Alpine temperature: High -6 Â°C. Ridge wind southwest: 10 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. Expect natural avalanche activity with the rapid loading. The Dec. 11th layer (surface hoar and facets) persists down 60-150cm, and continues to produce avalanches in shallow snowpack areas.

Avalanche Summary

Snow, and poor visibility made travel and observations difficult. Evidence of a large natural cycle continuing for the weekend.

Confidence

Due to the number of field observations

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.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very 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.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1.5 - 3.5

Deep Persistent Slabs

The base of the snowpack is weak and facetted. In shallow snowpack areas the new snow will likely overload this weakness.

Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.Avoid thin, rocky or unsupported slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1.5 - 4

Valid until: Jan 5th, 2019 4:00PM