Avalanche Forecast

Issued: Apr 12th, 2019 4:00PM

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

Timothy Johnson, Parks Canada

Jasper.

Use caution if venturing up high. New snow and wind could create pockets of windslab.

Summary

Weather Forecast

10cm of snow is forecast at the Parker Ridge area starting Saturday morning and increasing in intensity overnight. Treeline will be windy with 20-40 km/h westerlys. Freezing level will be around 1900m with a high of -2C. Expect the same closer to Jasper except with less snow. Note that forecast snow amounts have been inaccurate over the past week

Snowpack Summary

Forecast winds and snow could create windslabs in the alpine. A supportive crust exists to 2,100m on all aspects and extends into the alpine on solar slopes. A winter snowpack remains on N aspects above treeline. At upper elevations a weak faceted layer down 20-50cm remains a concern. The snowpack sits on a weak base of facets and depth hoar.

Avalanche Summary

Signs of cornice failures up to size 2 have been reported and a large serac triggered avalanche was witnessed off the south side of Mt. Kitchner on Thursday. Large whumpfs on the ridge of Mt. Wilcox were also reported on Thursday.

Confidence

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

Problems

Wind Slabs

Fresh snow and moderate winds could create windslabs in the alpine and at treeline.

Use caution in lee areas. Wind loading could create slabs.Minimize overhead exposure during periods of heavy loading from wind.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

Evidence from recent snowpack tests and whumphing would suggest that a weak layer of facets persists down 20-50cm in some areas, and may be becoming reactive with incremental loading from recent small snowfalls.

Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.

Aspects: North, North East, East, West, North West.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 2.5

Loose Dry

Expect loose dry avalanches out of sheltered north alpine features.

Be cautious of sluffing in steep terrain.

Aspects: North, North East, North West.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Apr 13th, 2019 4:00PM