Avalanche forecast

North Rockies

Dec 28 – 29, 2023Avalanche Canada
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Avalanche danger

Sat
Sun
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

There have been no field observations in the past few days. Submit a MIN if you head out!

Uncertainty around buried weak layers is best managed with conservative terrain choices.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Recent strong southerly winds have likely formed wind slabs on a variety of aspects in lee features in exposed terrain at treeline and above.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–3

    Buried surface hoar may remain rider-triggerable. This layer is of greatest concern around treeline elevation in areas where a significant crust is not found above it.

Confidence

Low

Avalanche Summary

There have been very few reports from this region in the past few days.

Last weekend, there were numerous reports of natural and skier-triggered persistent slabs, mainly at treeline, up to size 2. Check out this MIN from Powder King on Saturday and this MIN in Torpy on Friday. We suspect these avalanches ran on one of the surface hoar layers in the top meter of the snowpack.

Moving forward, natural activity is expected to taper, but large human-triggered slabs remain possible.

Snowpack Summary

Recent strong winds have created heavily wind-affected surfaces in the alpine and treeline. Below treeline a new crust is on or near the surface.

The mid pack contains several layers of note; a layer of surface hoar down 30 to 50 cm, a significant crust from the early December rain event down around 60 cm and a layer of surface hoar down 70 to 120 cm.

Snowpack depth throughout this region is highly variable and as a result the depths of the above mentioned layers are approximate and could be different than what you find in your riding area.

Weather Summary

Wednesday Night

Partially cloudy, no new snow. South alpine wind 40 to 70 km/h. Treeline temperature 0 °C. Freezing level rising to 1500 m in the north, 2500 m in the south.

Thursday

A mix of sun and cloud, no new snow. South alpine wind 50 to 70 km/h. Treeline temperature -1 °C. Freezing level 1400 m.

Friday

Partially cloudy, no new snow. South alpine wind 40 to 50 km/h. Treeline temperature 0 °C. Freezing level 1700 m.

Saturday

Mainly cloudy, no new snow. South alpine wind, 20 to 40 km/h. Treeline temperature 1 °C. Freezing level 2000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Any steep opening in the trees should be treated as suspect right now.
  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Use careful route-finding and stick to moderate slope angles with low consequences.

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