Avalanche Forecast

Issued: Feb 3rd, 2022 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 Persistent Slabs.

Deryl Kelly,

Jasper.

Steady SW winds building ongoing slab problem; previous reverse loading means problem may exist on all aspects.

Summary

Weather Forecast

Friday: Cloudy with scattered flurries. 5 cm. Temp: High -8 °C. Wind SW: 20 km/h gusting to 50 km/h.

Saturday: Cloudy with sunny periods and isolated flurries. Trace. Temp: Low -10 °C, High -7 °C. Wind SW: 20 km/h gusting to 55 km/h.

Sunday: Cloudy with sunny periods. Nil. Temp: Low -11 °C, High -8 °C. Wind SW: 20 km/h.

Snowpack Summary

New snow with previous N and present SW winds building slabs in alpine and tree line lee features. Varied wind effect at all elevations. Snowpack is facetted and complex. Buried surface hoar found in isolated locations; December facet layers down 20-40cm still reactive in tests.

Avalanche Summary

No new avalanches reported from road patrol today. Explosive control Wednesday produced several avalanches up to size 1 dry loose and size 2 wind slab Medicine lake area.

Confidence

Intensity of incoming weather systems is uncertain on Friday

Problems

Wind Slabs

Recent snow is available for transport on the Icefields Parkway and Maligne area. Likely isolated areas where new windslab building on existing reactive slabs, northerly aspects.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Be aware of the potential for wide propagations due to the presence of hard windslabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

Persistent slabs sit over different weak layers depending on elevation & aspect. Above 1950m a buried facet layer down 20-40cm is the primary concern. Below 1950m, a faceting crust down 40-70 is presenting a more stubborn version of a similar problem

Dig down to find and test weak layers before committing to a line.
Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 4th, 2022 4:00PM