Avalanche Forecast

Issued: Jan 22nd, 2017 4:00PM

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

max darrah, Parks Canada

Jasper.

Summary

Weather Forecast

No new precipitation on the horizon. Slight cooling and cooling trend towards mid-week, with calm to light Southerly winds.

Snowpack Summary

Recent 20-30cm of rapidly settling and wind distributed storm snow overlies facets and basal weakness. New reactive windslabs in lee gully features and especially on NE aspects. Extensive scouring of last weeks snowfall at and above treeline.

Avalanche Summary

Good results (several size 2 to 2.5 in steep rocky alpine terrain) in recent explosive control work at Marmot ski hill, suggests that the weak basal layer is reactive to large loads. No patrol in the Columbia Icefield area today.

Confidence

Due to the number and quality of field observations

Problems

Wind Slabs

Main concern is for cross loaded gully features and steep rocky convexities on lee aspects where fresh windslabs are present.

Use caution in lee areas. Recent wind loading has created wind slabs.Be careful with wind loaded pockets while approaching and climbing ice routes.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Deep Persistent Slabs

The weak lower snowpack is susceptible to triggering in lee areas that have been recently loaded by SW winds and last week's snow.

Watch for whumpfing, hollow sounds, and shooting cracks.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Jan 23rd, 2017 4:00PM