Avalanche Forecast

Issued: Jan 25th, 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.

Avalanche Canada jleblanc, Avalanche Canada

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Be aware of riding conditions that change with elevation, aspect and exposure to wind. Locally strong winds have formed slabs in more sheltered areas. 

Summary

Confidence

High - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

An upper ridge over the province will give dry conditions for the next couple of days, although some low clouds will persist in interior valleys. It will gradually start shifting east by Friday morning, opening the door for a change in the weather pattern for the weekend.

TUESDAY NIGHT: Cloudy with isolated flurries / Gusty west wind to 60 km/h/ Low temperature -8 C / Freezing level at 1000 m lowering to valley bottom.

WEDNESDAY: Cloudy with sunny periods / Strong and steady northwest wind 50 km/h / High temperature -4 C / Freezing level at valley bottom.

THURSDAY: Mix of sun and cloud / Strong and steady northwest wind 50 km/h / High temperature -2 C / Strong temperature inversion / Freezing level around 1000 m, except 2000-2500 m around Kakwa.

FRIDAY: Cloudy with isolated flurries / Moderate southwest wind gusting 50 km/h / High temperature -4 C / Freezing level around 1000 m.

Avalanche Summary

No new avalanches were reported nor observed in the last 24h. 

Evidence from last weekend, including small human-triggered wind slab avalanches and cornice falls (up to size 1.5), are still visible in places. 

Snowpack Summary

Recent strong wind has hit the region hard, stiffening 20-35 cm of recent snow in open areas at treeline and throughout the alpine. Gusty winds have loaded terrain further downslope than usual. Strong sun from Monday has produced a thin sun crust on solar aspects. Surface hoar was noticed in sheltered areas up to the alpine. Cool overnight temperatures have produced a surface crust at lower elevations up to 1500 m. See our field team photos from Anzac on Sunday.

A thin crust is found under the recent snow, which was responsible for wind slab activity over the past weekend. Another crust is found down 70 cm but has not shown recent reactivity. The lower snowpack is generally strong and bonded, with one or multiple crusts near the ground. We suspect the lower snowpack could be weak in shallow rocky wind-affected slopes east of the divide.

Terrain and Travel

  • Watch for areas of hard wind slab on alpine features.
  • Pay attention to isolated alpine features as well as cross-loaded features at treeline.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.

Problems

Wind Slabs

An icon showing Wind Slabs

Strong and steady wind will continue to stiffen recent slabs and build fresh ones further down slope where it finds loose snow. Wind slabs have been most reactive where they overlie a thin crust. Steep, convex and unsupported slopes are the features of concerns for triggering wind slabs.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Jan 26th, 2022 4:00PM