Avalanche Forecast
Issued: Feb 2nd, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
Jeff Andrews,
Strong to extreme southwest winds and new snow on Friday adding to slab problem in the alpine and tree line. Snowpack is variable - dig and test to see what's happening where you are. Maligne road forecast to open mid day Thurs - 511 for updates.
Summary
Weather Forecast
Thursday: Cloudy isolated flurries. Alpine temp: High -10 C. Wind west 20 km/hr.
Friday: Flurries - up to 9cm. Alpine temp: Low -9 C, High -7 C. Wind west 30 gust 85 km/hr.
Saturday: Variable cloud isolated flurries. Alpine temp: Low -14 C, High -11 C. Wind west 20 gust 50 km/hr.
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. Upslope storm last Sunday produced up to 35cm in the Maligne Range.
Avalanche Summary
Explosive control Wednesday produced several avalanches up to size 1 dry loose and size 2 wind slab Medicine lake area.
Confidence
Problems
Wind Slabs
Recent snow is available for transport on the Icefileds Parkway and Maligne area. This new snow will make previous wind slab difficult to spot. Be on the lookout for reverse loading caused by previous northerly winds.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
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
- Avoid shallow snowpack areas where triggering is more likely.
- Dig down to find and test weak layers before committing to a line.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 3rd, 2022 4:00PM
