Avalanche Forecast

Issued: Dec 1st, 2022 4:00PM

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

Avalanche Canada dsaly, Avalanche Canada

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The recent snow is not bonding well to the surface below, and will easily be redistributed by any fresh wind. Choose conservative terrain and investigate the bond of the new snow.

Summary

Confidence

Low

Avalanche Summary

No new avalanches have been observed or reported in this region. However, note that we have had no field observations in for this forecast region this winter.

Potential for skier-trigger avalanches are likely to be found on terrain features that harbor additional snow such as just below ridgetops and on steep wind-loaded slopes.

Snowpack Summary

Another 5-10 cm accumulated Thursday morning, with 15-30 cm total snowfall accumulated in the last few days. In the short term, reports suggest the new snow is not bonding to a layer of surface hoar below.

Early-season conditions exist with low snow amounts and crusts found at lower elevations. A deeper and drier snowpack exceeding 1 m is found at treeline and alpine elevations.

Around 65 cm of snow overlies a weak layer that formed mid-November that consists of sugary faceted grains, weak surface hoar crystals in sheltered terrain features, and a hard crust on steep sun-exposed slopes. The lower snowpack presents as well settled.

Weather Summary

Thursday night

Mostly cloudy with starry breaks. 10-15 km/hr west wind, treeline temperatures fall below -20 °C.

Friday

Increasing clouds through the day with light flurries starting late in the afternoon. Increasing southwest wind 15-25 km/hr. Treeline temperature high -12 °C.

Saturday

Gusty winds and scattered flurries overnight, trace to 5 cm accumulating by Saturday morning. Southwest wind 20-30 km/hr decreasing through the day. Treeline high temperature -6 °C.

Sunday

Clear, cold, and calm. Light northeast wind, treeline temperatures falling to -12 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
  • Closely monitor how the new snow is bonding to the old surface.

Problems

Storm Slabs

An icon showing Storm Slabs

Reports suggest the recent 10-30 cm is poorly bonded to the interface below (a layer of surface hoar). Keep an eye on the wind, slabs may quickly form wherever the wind encourages the fresh snow to bond; and with a weak layer of surface hoar below, reactive slabs may be more widespread and extend into treeline elevations and be more reactive than expected in sheltered areas.

The "upper" early winter snowpack consists of around 60 cm of recent snow over various layers formed mid-November, including surface hoar, faceted grains, and a hard crust. While our avalanche concern is focused on the interface just below the recent snow, we're hoping to gain more information on the distribution and sensitivity of these deeper layers as we collect more field observations.

Avalanche hazard is unlikely at lower elevations where snowpack depths have yet to overcome ground roughness like brush and rocks.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 2nd, 2022 4:00PM