Avalanche Forecast

Issued: Mar 6th, 2023 4:00PM

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

Avalanche Canada lbaker, Avalanche Canada

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Continually monitor conditions as you move through terrain.

There is a lot to keep in mind; the likelihood of triggering slab avalanches will increase if solar input occurs, wind slabs could be found on all aspects and there is some uncertainty in distribution of the persistent slab problem.

If in doubt choose simple terrain.

Summary

Confidence

Moderate

Avalanche Summary

On Sunday several wind slab avalanches were reported up to size 2 between 1800 and 2400 m on westerly and northerly aspects. A skier accidental, size 1.5, wind slab avalanche was reported on a northeast aspect at 1900 m.

Late last week, several skier triggered avalanches, up to size 2.5, were reported. Many of these avalanches failed on weak layers from February and January and occurred at treeline.

Check out this MIN from Saturday showcasing the current wind slab problem.

Snowpack Summary

Storm totals from the past week average 40 to 60 cm. Expect to find wind slabs on all aspects due to shifting wind direction. This storm snow sits over a wind affected layer at all elevations.

A layer of surface hoar can be found on shaded slopes, and a sun crust on sun affected slopes buried 40 to 70 cm deep. Another layer from January is buried up to 50 cm below this. These layers have been noted as a failure plane for some avalanche activity.

The lower snowpack includes a layer of weak sugary crystals near the ground. These facets are slowly gaining strength and have not produced recent avalanche activity. We continue to track the layer and watch for any signs that it could wake up and produce very large avalanches.

Weather Summary

Monday Night

Scattered clouds and isolated flurries, trace accumulation. Light southwest winds. Treeline temperature low of -8, and freezing levels at valley bottom.

Tuesday

Partly cloudy with the possibility of light flurries bringing trace amounts of new snow. Light variable winds. Treeline temperature high of -5, and freezing levels around 1200 m.

Wednesday

Mostly sunny. Moderate southeast winds gusting strong. Treeline temperature high of -4, and freezing levels around 1300 m.

Thursday

Sunny with cloudy periods. Light southeast winds. Treeline temperature high of -6, and freezing levels around 1000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Minimize exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Surface hoar distribution is highly variable. Avoid generalizing your observations.

Problems

Wind Slabs

An icon showing Wind Slabs

Variable winds over the past few days mean that wind slabs could be found on all aspects. Periods of strong winds may have formed wind slabs further down slope than usual.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

There are two layers of concern in the upper and mid pack. These layers are generally made up of facets and surface hoar but on south aspects a crust can be found. These layers are most likely to be triggered on sparsely treed slopes at treeline and below.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Mar 7th, 2023 4:00PM