Avalanche Forecast

Issued: Jan 20th, 2022 4:00PM

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

Avalanche Canada mconlan, Avalanche Canada

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Recently formed slabs will need some time to bond to the snowpack.

Summary

Confidence

High - We have a good understanding of the snowpack structure and confidence in the weather forecast

Weather Forecast

THURSDAY NIGHT: Cloudy with snowfall, accumulation 2 to 5 cm, 40 km/h west wind, alpine temperature -4 C, freezing level 1000 m.

FRIDAY: Mostly cloudy with intermittent snowfall, accumulation 1 to 3 cm, 50 km/h southwest wind, alpine temperature -2 C, freezing level 1000 m.

SATURDAY: Cloudy with intermittent snowfall, accumulation 1 to 3 cm, 60 km/h southwest wind, alpine temperature 0 C, freezing level 1000 m with above-freezing level possible between 1800 m and 2400 m.

SUNDAY: Cloudy with early-morning snowfall, accumulation 2 to 5 cm, 30 km/h northwest wind, alpine temperature -2 C, freezing level 1000 m.

Avalanche Summary

Early evidence of a widespread avalanche cycle was observed on Thursday, occurring during Wednesday night's storm. 

Natural avalanche activity is expected to decrease on Friday but human triggering remains likely.

Snowpack Summary

Around 30 to 50 cm of snow fell on Wednesday night into Thursday, with snow switching to rain up to around 1000 m around the Terrace area. Storm slabs rapidly built during the storm along with wind slabs in terrain exposed to the wind from strong southwest wind. The snow may sit on surface hoar crystals, which may also sit above a hard melt-freeze crust up to around 1300 m.

A layer of sugary facetted grains may be found about 80 to 130 cm deep, which formed during the cold spell in late December to early January. To date, this layer has only been problematic in the northern half of the region.

The remainder of the snowpack is strong in the south of the region. In the north of the region, the base of the snowpack consists of faceted grains around a melt-freeze crust, which is currently dormant.

Terrain and Travel

  • Good day to make conservative terrain choices.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Make observations and assess conditions continually as you travel.
  • Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.

Problems

Storm Slabs

An icon showing Storm Slabs

Around 30 to 50 cm of snow has formed touchy storm and wind slabs. Storm slabs are most likely in areas sheltered from the wind and wind slabs are prominent in wind-exposed terrain from strong southwest wind. This snow may remain touchy for a few days, particularly where it overlies weak surface hoar crystals, which also may sit on a hard melt-freeze crust.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Jan 21st, 2022 4:00PM