Avalanche Forecast

Issued: Dec 17th, 2022 4:00PM

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

Avalanche Canada wlewis, Avalanche Canada

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Watch for fresh wind slab development as new snow accumulations build. Expect reactivity, slabs form over a surface hoar and crust combination.

Summary

Confidence

Moderate

Avalanche Summary

Warm temperatures and sunshine on Friday caused wet loose avalanches at low elevations to size 1.5.

If you head out into the mountains, please share your photos or observations on the Mountain Information Network. Your information helps us understand local conditions!

Snowpack Summary

In exposed terrain at higher elevations, pockets of wind slab sit in wind loaded features while rocks may be exposed on others. Large surface hoar has been reported on the surface in sheltered areas, with a crust present on solar aspects. 40 to 70 cm of settling snow sits in the upper snowpack.

The mid and lower snowpack consist of crusts and facet layers which are ongoing concerns in this area. Reports suggest that these layers are stronger than what's found in other regions (e.g. the Duffy or Hurley). Recent test results show these layers are reactive, however there has been no significant avalanche activity reported yet.

Snowpack depths at treeline reach 200 cm in some areas, but decrease rapidly below 1500 m.

Weather Summary

An Arctic front dominates the weather over BC. Light snowfall is expected Saturday night as a low south of Vancouver Island briefly competes with the cold air, directing snowfall up the Fraser Valley.

Saturday Night

Mostly cloudy with moderate to strong westerly winds. Freezing level below valley bottom. Snowfall expected, up to 10-15 cm in the Fraser Valley.

Sunday

Partly cloudy with around 5-15 cm of snow expected, again favoring the Fraser Valley. Moderate to strong westerly winds at ridgeline. Freezing level below valley bottom. Alpine high of -15 °C.

Monday

Mostly cloudy with moderate to strong southwest winds. Alpine highs of -20 °C. Isolated flurries possible.

Tuesday

A mix of sun and cloud with moderate westerly winds. Freezing level below valley bottom. Moderate snowfall possible with alpine high temperatures of -25 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Wind slabs are most reactive during their formation.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Sheltered slopes at lower elevations will offer the best riding.

Problems

Wind Slabs

An icon showing Wind Slabs

Small but reactive new wind slabs are likely form with snowfall overnight Saturday and into Sunday. Expect to find wind loading on all aspects as winds switch from north to southwest. Slabs may be poorly bonded to the crust below.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 18th, 2022 4:00PM

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