Avalanche Forecast

Issued: Feb 6th, 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 Loose Dry.

mark herbison, Parks Canada

Jasper.

Recent moderate Northerly winds and 10cm of storm snow have built wind slab over a sensitive faceted interface.

Summary

Weather Forecast

Clearing throughout the day on Tuesday, cold temps (alpine high of -22), light NE winds and no new precipitation. Wednesday night will see another low pressure system move in, bringing ~20cm of snow by Thursday night, warmer temps (alpine high of -8) with strong SW winds.

Snowpack Summary

10cm of storm snow (past 48hrs) with light-moderate NE winds have loaded Southerly aspects. Surface faceting and surface hoar (Feb 3) has been buried creating a weak interface in the upper snowpack. Poor bonding between these layers is expected. The mid-pack is facetted and weak with depth hoar at its base.

Avalanche Summary

No new avalanche observations or reports today, though visibility was limited.

Confidence

Intensity of incoming weather systems is uncertain on Thursday

Problems

Wind Slabs

Moderate NE winds have transported 10cm of storm snow onto south westerly slopes building windslab. These new slabs will bond poorly. Last week's slab from M to S winds are still suspect. Big open features and cross-loaded gulleys should be avoided.

Use caution in lee areas. Recent wind loading have created wind slabs.Keep an eye out for reverse loading created by an upslope storm.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Dry

10cm of storm snow over facets can be easily triggered and grow quickly by entraining surrounding snow especially in gulley features.

Sluffs may trigger deeper instabilities.Be cautious of sluffing in steep terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Feb 7th, 2017 4:00PM