Avalanche Forecast

Issued: Jan 2nd, 2019 4:53PM

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

jasper snow safety, Parks Canada

Jasper.

The incoming storm is expected to initiate a significant natural avalanche cycle.Highway 93N will be closed from the Saskatchewan Crossing to 10km South of the Icefields center on Thursday at 07:00 hrs. Expected opening by Friday evening.

Summary

Weather Forecast

A series of fronts moving inland from the central coast will give heavy snowfall and strong winds to our area. Thursday: Up to 35cm of snow will fall with strong to extreme south west winds. Alpine temps will be high -5, Low -7.Friday: 15cm of snow with ongoing wind.A detailed mountain weather forecast is available from Avalanche Canada.

Snowpack Summary

Incoming new snow and strong SW winds will build fresh windslabs in open terrain and storm slabs in sheltered areas.Â Expect natural activity to increase. The Dec. 11th layer (surface hoar and facets) persists down 50-110cm, and has been gaining strength but continues to produce avalanches in shallow snowpack areas.

Avalanche Summary

A skier triggered and several natural slabs were noted today on NE aspect slopes in thin shallow snowpack area's around the Columbia icefields. A field trip into the parkers area today noted wide spread wind effect in any open terrain, with sustrugi forming in open TL features and above.

Confidence

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

Problems

Wind Slabs

Fresh snow and strong to extreme SW winds at all elevations, expect wind effect in all open terrain.

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: North, North East, East, South East, North West.

Elevations: All elevations.

Likelihood

Likely - 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

Possible

Expected Size

1.5 - 3

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 thin, rocky or unsupported slopes.Avoid areas with overhead hazard.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3.5

Valid until: Jan 3rd, 2019 4:00PM