Avalanche Forecast

Issued: Feb 19th, 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.

Avalanche Canada trettie, Avalanche Canada

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Use caution in wind effected terrain, wind slab over facets, surface hoar or a crust remains the primary concern.

Summary

Confidence

Moderate

Avalanche Summary

Over the past week we have seen a pattern of human and remotely triggered size 1 to 1.5 wind slab avalanches with a few being up to size 2. Human-triggered avalanches have occurred on a range of aspects. Slabs have been averaging 20 - 30 cm thick, with some failing on buried surface hoar and propagating widely.

Snowpack Summary

Sun and wind have created variable surface conditions. All exposed terrain is highly wind effected. A crust exists on all aspects at lower elevation and up to mountain tops on south aspects. The snow surface will likely become moist throughout the day.

Roughly 30 cm of snow sits above large surface hoar and/or faceted crystals at treeline and above. This is most problematic in places where wind slabs have formed over it. A widespread, supportive crust exists 30 to 40 cm below the surface. It is an excellent bed surface for slabs run to on.

The snowpack is well bonded and strong below this crust.

Weather Summary

Monday Night

Mostly cloudy  with trace amounts of new snow possible. 10 to 20 km/h south alpine wind.  Treeline temperature -2°C, potential temperature inversion with colder temps at valley bottom.

Tuesday

Mostly cloudy with up to 5 cm of new snow expected in the alpine. 15 to 30 km/h southwest alpine wind. Freezing level rising to 1700 m.

Wednesday

Mostly cloudy with up to 10 mm of mixed precipitation expected. 15 to 30 km/h southeast alpine wind. Freezing level around 1900 m.

Thursday

Mostly cloudy with up to 5 cm of new snow expected in the alpine. 5 to 15 km/h southeast alpine wind. Freezing level around 1600 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Keep in mind that human triggering potential persists as natural avalanching tapers off.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.

Problems

Wind Slabs

An icon showing Wind Slabs

Previous outflow wind has impacted open terrain on various aspects. This has formed wind slabs that are bonding poorly to underlying surface hoar and facets on the early February crust.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 20th, 2024 4:00PM