Avalanche Forecast

Issued: Dec 17th, 2019 4:00PM

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

Parks Canada Jasper Snow Safety, Parks Canada

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The wind is ripping through the forecast region with forecasted speeds exceeding 80 kph. Assess slopes carefully for slab development.

Summary

Weather Forecast

Wednesday will be cloudy with sunny periods and isolated flurries, a trace of snow, -7, southwest winds 15-35 km/h. Strong winds area expected Tuesday evening into Wednesday. Thursday will be similar. Friday may bring 20cm of snow we hope.

For more details: Mountain Weather Forecast

Snowpack Summary

Moderate SW winds and high relative humidity firming up the top 30cm creating soft and hard slabs. The snow depth is variable at all elevations. There is a mid-pack crust/facet layer distributed through the region. It has mixed reactivity. A weak basal facet/depth hoar layer exists at the base of the pack.

Avalanche Summary

No field patrol Tuesday. Last few days there have been no new avalanches observed or reported.

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Confidence

Wind effect is extremely variable on Wednesday

Problems

Wind Slabs

An icon showing Wind Slabs

Strong SW winds are creating wind slabs in NW to SE lee aspects. Sensitivity expected to be reactive in the immediate future and might be enough to wake deep, weaker interfaces.

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • Be careful with wind loaded pockets while approaching and climbing ice routes.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

A few large avalanches were observed during last cycle early in December and we suspect it was on this layer. Triggering the windslab problem has potential to release this lower problem layer.

  • Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2.5

Valid until: Dec 18th, 2019 4:00PM