Avalanche Forecast

Issued: Jan 26th, 2022 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 Persistent Slabs.

Catherine Brown,

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Rising freezing level Thursday may weaken cornices and cause them to fail.

Watch for this overhead hazard and plan to travel early on exposed slopes.

Summary

Weather Forecast

This week a ridge of high pressure brings dry days, some valley cloud and seasonal temperatures.

Tonight: Cloudy with clear periods, Alp low -8*C, light NW winds

Thurs: Sun and cloud, Alp high -2*C, light SW ridgetop winds, fz lvl:1300m

Fri: Sun and cloud, Alp high -3*C, mod SW winds, fz lvl:1100 m

Sat: Sun and cloud, Alp high -4*C, mod SW winds

Snowpack Summary

Surface hoar rowing on surface, 5-8mm BTL, 2-4mm TL and above. Variable breakable surface crust exists on S-W aspects. Wind-affect can be found at treeline and above. The Jan 20 (2-4mm) surface hoar down 35cm, and Jan 11 (2-5mm) surface hoar down 70-90cm. The Dec 1 crust/facet combo is down ~1.5 - 2.5m and will require a big trigger to come alive.

Avalanche Summary

Observations from Jan 25th:

No new avalanches observed in the highway corridor nor in the Sir Donald/Avalanche Crest area.

A backcountry report of a natural cornice fall in the loop brook drainage triggering a size 3.0 avalanche.

A field team in the Sir D/Avalanche Crest zone ski-cut small features to 40* with no results.

Confidence

The weather pattern is stable

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs can be found in the Alpine and at Treeline. Watch for these firm deposits of snow on lee features. The Jan 20th surface hoar is present beneath these slabs.

  • Convex features and steep unsupported slopes will be most prone to triggering.
  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

Several persistent weak layers (see snowpack summary) are present in the upper 1m. Test the strength of these layers before committing to your line.

  • Be wary of slopes that did not previously avalanche
  • If triggered the persistent slabs may step down to deeper layers resulting in very large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 2.5

Valid until: Jan 27th, 2022 4:00PM

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