Avalanche Forecast

Issued: Mar 15th, 2020 4:00PM

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

Parks Canada Jonathan Simms, Parks Canada

Be weary of hard slabs in large alpine/treeline features.

Summary

Weather Forecast

A warm upper ridge over the eastern Pacific is beginning to move in from the west, which will gradually flush out the Arctic air that was entrenched over most of Western Canada.  More detailed forecast at: Mountain weather forecast

Snowpack Summary

A variety of wind affected surfaces. Wide spread scouring, stripping in exposed places. Hard slabs, soft slabs, sastrugi now present. The Icefields area has a well bridged mid pack overlying basal facets and depth hoar. The northern region is weaker with less bridging midpack strength above basals and depth hoar.

Avalanche Summary

Today: Few size 1-2 loose dry in steep alpine steep rock/gullies due to solar.

Confidence

Problems

Wind Slabs

An icon showing Wind Slabs

Previous NE winds reverse loaded alpine features North of Sask x'ing. More evident in the North bulletin area. This, in combination with basal facet issue produced a few random large destructive avalanches yesterday.

  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
  • Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Several natural large avalanches observed yesterday due to the combination of rapid wind loading initiating basal facets or reloaded bed surfaces.

Mnt Athabasca ramp route ran size 3.5. Impressive avalanche running into the rock basin below.

  • Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.
  • Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 3.5

Valid until: Mar 16th, 2020 4:00PM