Avalanche Forecast

Issued: Jan 1st, 2019 4:23PM

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

jonas hoke, Parks Canada

Jasper.

Snowpack depths and avalanche problems vary significantly through out the forecast region. Re-assessment is essential if you are venturing into new areas.

Summary

Weather Forecast

A ridge of high pressure to our south gets pushed out by a frontal system later in the week. Wednesday: mostly cloudy with isolated flurries. Alpine temps high -8C, low -10C. Winds will be L-M SW.Snowfall Wed. night through Friday with total accumulations of up to 50cm.A detailed mountain weather forecast is available from Avalanche Canada.

Snowpack Summary

35cm of low density snow that fell in the southern half of the region on Saturday. Strong to extreme SW winds during the storm produced widespread wind effect in any open terrain. The Dec. 11th interface is still easily identified down 50-110cm and continues to produce hard but sudden test results, and was reactive to large triggers recently.

Avalanche Summary

Little natural activity noted on Monday's field trip to E facing slopes across from Mt. Coleman and visibility was good. One recent large avalanche in the Boundary area likely failed on the Dec. 11th interface, and scrubbed to ground in places. Sunday's avalanche control produced loose dry avalanches to size 1.5 on the immediate roadside targets.

Confidence

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

Problems

Wind Slabs

The recent snow came with strong winds at all elevations, wind effect is visible in all open terrain.

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

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 2.5

Loose Dry

Be particularly cautious in steep areas with shallow snowpack, were the new snow is sitting on unconsolidated facets and depth hoar.

Be cautious with gully features.Avoid traveling on ledges and cliffs where small avalanches may have severe consequences.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

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 to large triggers such as cornices recently.

Be wary of slopes that did not previously avalanche.Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1.5 - 3

Valid until: Jan 2nd, 2019 4:00PM