Avalanche Forecast

Issued: Mar 21st, 2023 2:00PM

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

Avalanche Canada Dvonk, Avalanche Canada

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Wednesday is calling for +8 in Canmore, and sunny skies. Consider your over head (solar slopes and cornices) when you are traveling throughout the day. Perfect sunny touring weather at the moment!

Summary

Confidence

Moderate

Avalanche Summary

A road patrol today down the spray road noted no new avalanches, However there is good evidence of slabs pulling out over the last week. On solar slopes along the road, pinwheeling is starting to be observed,

Snowpack Summary

The fresh snow from last week has largely escaped the wind.....so far. Many areas still have soft snow, but expect sun crusts on solar aspects at all elevations where the terrain is steeper than about 20 degrees. The strong late March sun is melting these surface crusts and destabilizing the slopes. There are previously formed wind slabs in alpine areas, so keep an eye out for these in lee and cross-loaded features. The midpack remains highly variable with areas of more than 100cm of total snowpack being supportive, but in shallower areas ski penetration can still be to ground. The good old facets and depth hoar still lurk at the bottom of the snowpack and present an ongoing concern for full-depth avalanches. Expect the avalanche hazard to deteriorate throughout the day with the solar input and rising freezing level. This will be of greatest concern under larger features where the solar radiation could trigger the deep persistent layer.

Weather Summary

Wednesday: SUNNY, high of -3 with 15km/h west winds. Freezing levels will rise to 2200m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Cornices become weak with daytime heating or solar exposure.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Avoid exposure to large features as the deep persistent slab can be triggered with solar radiation. The alpine is still variable in total amounts of snow but the basal layers haven't changed. The entire lower half is either facets or depth hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3.5

Persistent Slabs

An icon showing Persistent Slabs

On solar aspects this slab most likely is starting to sit on top of buried sun crusts on S-W aspects. On polar aspects the interface is facets and surface hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Mar 22nd, 2023 4:00PM

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