Avalanche Forecast

Issued: Jan 12th, 2024 4:00PM

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

Avalanche Canada wlewis, Avalanche Canada

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Wind effected storm snow still needs time to settle and bond with old surfaces, which takes extra time in the cold.

Factor cold temperatures and wind chill in your trip plan this weekend.

Summary

Confidence

Moderate

Avalanche Summary

Size 2 slab avalanches were reported on north and east facing slopes during Tuesday's storm. Reactivity is expected to continue in wind loaded features.

On Wednesday a size 2.5 naturally triggered persistent slab was reported on a northwest facing slope in the alpine, which had reloaded from a previous recent avalanche.

Last Saturday, a very large avalanche was reported on Joffre shoulder, suspected to have failed on the weak layer of facets or surface hoar over a crust.

Snowpack Summary

Up to 50 cm of available snow is being redistributed into wind slabs on south facing slopes from these arctic winds. Slabs overly wind affected surfaces in most areas.

A crust is found at treeline and below, 40-80 cm down. In some areas, a layer of preserved surface hoar is found above the crust.

Another weak layer of facets or surface hoar overlying a crust is found at the base of the snowpack down 80 to 120 cm. This is the suspected failure plane for large avalanches in the region that occurred on January 6.

Snowpack depths are 100 to 140 cm at treeline and decrease rapidly below.

Weather Summary

Friday Night

Clear skies with northerly winds 10-30 km/h. Treeline temperature remains steady around -30 °C.

Saturday

Sunny with northerly winds 10-30 km/h. Treeline temperatures rise to -20 °C.

Sunday

Sunny with northerly winds 20-40 km/h. Treeline temperatures rise to -17 °C.

Monday

Sunny with northerly winds 20-40 km/h. Treeline temperatures rise to -13 °C.

With unusually cold temperatures forecast for this weekend, check out the most recent Forecaster Blog for tips on backcountry preparedness.

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.
  • Expect slab conditions to change drastically as you move into wind exposed terrain.
  • Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs may be found near ridgelines or lower on the slope than usual. Watch for crossloading in unusual features like mid slope gullies and rollovers.

Aspects: East, South East, South, South West, West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

Buried weak layers produced avalanche activity within the last week. Uncertainty exists about ongoing reactivity. Avoid thin and shallow areas where triggering is more likely while the snowpack adjusts to the recent snowfall.

Aspects: North, North East, North West.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Valid until: Jan 13th, 2024 4:00PM