Avalanche Forecast

Issued: Nov 25th, 2023 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 wlewis, Avalanche Canada

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Avoid wind loaded terrain, recent avalanches show reactivity of weak layers near the ground in wind-affected features.

Summary

Confidence

No Rating

Avalanche Summary

On Friday a size 1.5 wind slab was explosively triggered near Pincher Creek.

A human triggered size 1 was reported near Invermere on Thursday at treeline on a west facing slope, failing on the facets at the base of the snowpack. To the north of the region, several natural size 2's also occurred on this layer.

Observations are limited, please consider filling out a MIN report.

Snowpack Summary

Surface conditions are variable. A sun crust can be found on some steep south and west facing slopes.  In the alpine and on exposed treeline features a mix of wind scouring and loading can be found from previous southwest winds.

A crust with facets or depth hoar exists at or near the ground. The snowpack is shallower than average for this time of year with depths at treeline ranging from 20 -50 cm, and tapers rapidly below.

Weather Summary

Saturday Night

Mostly clear skies with northwest winds 10-30 km/hr. No new snow expected.

Sunday

Mostly sunny skies with no new snow expected, northwest winds 20 to 40 km/h, treeline temperature -10°C.

Monday

Partly cloudy skies with no new snow expected, west alpine winds 25 to 40 km/h, possibly reaching 60 km/hr in the alpine. treeline temperature -11°C.

Tuesday

Mostly clear skies, winds remain strong at ridgeline, around 50 km/hr. No new snow.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avalanche danger is often elevated in alpine gullies where snow has accumulated.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Use ridges or ribs to avoid areas of wind loaded snow.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slab may be found in exposed terrain at treeline and above. Slabs may overlie a layer of facets and depth hoar that sits above the ground, resulting in more reactivity and larger avalanches than expected.

Aspects: North, North East, East, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 26th, 2023 4:00PM

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