Avalanche Forecast

Issued: Mar 23rd, 2020 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 mconlan, Avalanche Canada

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There is uncertainty in the forecast due to a lack of data available at this time.

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

MONDAY NIGHT: Cloudy with isolated flurries, accumulation 2 to 5 cm, light northeast wind, alpine temperature -10 C.

TUESDAY: Morning clouds and afternoon clearing, moderate north wind, alpine temperature -12 C.

WEDNESDAY: Clear skies, moderate northwest wind, alpine temperature -6 C, freezing level 1000 m.

THURSDAY: Cloudy with snowfall accumulation 5 to 10 cm, moderate to strong west wind, alpine temperature -6 C, freezing level 800 m.

Avalanche Summary

No new avalanches were observed on Monday from limited reports. Looking forward, wind slab activity may increase as the wind speed increases and new slabs form.

Snowpack Summary

Around 5 to 15 cm of snow fell Sunday night with northeast wind. Wind slabs may form in areas where the wind speed picks up on Tuesday. These slabs will sit on a melt-freeze crust on sun-exposed slopes and otherwise previously wind-affected snow, so the new slabs may take some time to bond to the snowpack.

A weak layer of surface hoar crystals buried early March may be found around 30 to 50 cm deep, particularly in sheltered terrain around treeline.

An early-season layer of faceted grains and melt-freeze crust near the base of the snowpack may linger. The most suspect locations to trigger this layer would be where the snowpack is thin near rocky outcrops. A large load, such as a cornice fall, also has the potential of triggering it.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • Make conservative terrain choices and avoid overhead hazard.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs may form as the wind speed picks up, transporting Sunday night's snowfall. Use added caution at higher elevations, particularly near ridge lines.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A weak layer of surface hoar crystals is buried around 30 to 50 cm in sheltered, shady terrain around treeline. Recent warm conditions have likely promoted bonding of this layer but there is uncertainty as to whether it is still a problem.

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

Elevations: Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Mar 24th, 2020 5:00PM