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 Persistent Slabs.

Avalanche Canada shorton, Avalanche Canada

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Be careful around steep open slopes where it's possible to trigger an avalanche on a buried weak layer.

Summary

Confidence

Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.

Weather Forecast

TUESDAY NIGHT: Clearing skies, light wind from the west, treeline temperatures drop to -8 C.

WEDNESDAY: Mostly clear skies with some valley cloud, moderate wind from the southwest, a weak inversion forms in parts of the region with above freezing temperatures around 2000 m, alpine temperatures around -6 C.

THURSDAY: Clear skies except for a possibility of valley cloud, strong wind from the southwest, treeline temperatures around -8 C.

FRIDAY: Storm arrives with cloudy skies and up to 5 cm of snow, strong wind from the southwest, treeline temperatures around -5 C.

Avalanche Summary

Over the weekend a few notable avalanches were reported including a snowmobile triggered avalanche near Silvern Lake that appeared to occur on a 30-50 cm deep surface hoar layer, and a few size 2-3 slab avalanches triggered by heavy machinery north of Hazelton that occurred on 30-70 cm deep layers (on northeast and southeast aspects around treeline). There were also reports of some large (size 2-3) naturally-triggered avalanches on wind-loaded slopes below cornices.

Snowpack Summary

Wind and warm temperatures have created variable surface conditions with heavily wind-affected snow in open terrain, surface crusts that likely extend into the alpine on south-facing slopes, and pockets of dry snow on some north-facing slopes. Recent avalanche activity suggests there are two weak layers in the upper snowpack: one is a 30 cm deep surface hoar layer (buried on Jan 19) and the other is a 40 to 70 cm deep layer of faceted snow (buried in early January). We are uncertain about the spatial distribution of these layers, but avalanche activity suggests they are most problematic in steep terrain at treeline and alpine elevations. In thin snowpack areas, there is some weak and facetted snow just above the ground, but this layer is not considered reactive at this time.

Terrain and Travel

  • Caution around convexities or sharp changes in terrain.
  • Be especially cautious as you transition into wind affected terrain.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Problems

Persistent Slabs

An icon showing Persistent Slabs

A handful of large avalanches the past few days suggest buried weak layers in the top 70 cm of the snowpack could still produce avalanches. A noticeable trend is these avalanches have occurred in wind-affected terrain. Be careful with your terrain selection and be extra cautious around big slopes and steep convexities.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 2.5

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