Avalanche Forecast

Issued: Mar 25th, 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 cgarritty, Avalanche Canada

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New snow and elevated winds will introduce a fresh surface instability to the region.

Summary

Confidence

Low - Forecast snowfall amounts are uncertain. Uncertainty is due to the limited number of field observations.

Weather Forecast

Wednesday night: Becoming cloudy with flurries bringing about 5 cm of new snow, increasing in the morning. Moderate to strong west winds.

Thursday: Cloudy with continuing flurries bringing about 10 cm of new snow, easing overnight. Moderate to strong west winds. Alpine high temperatures around -8.

Friday: Cloudy with isolated flurries and up to 5 cm of new snow, increasing overnight. Moderate to strong southwest winds. Alpine high temperatures around -9.

Saturday: Cloudy with continuing flurries bringing about 5 cm of new snow. Moderate to strong southwest winds. Alpine high temperatures around -9.

Avalanche Summary

No new avalanches were observed on Monday or Tuesday from limited reports. 

Looking forward, new snow and wind forecast through Thursday are likely to form small but touchy new wind slabs in leeward terrain, especially near ridgetop.

Snowpack Summary

Surface conditions over the region are likely a mix of recent wind slabs and wind-affected snow as well as melt freeze crust on south aspects and below about 1100 metres.

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. Recent observations of this layer are lacking.

An early-season layer of faceted grains and melt-freeze crust near the base of the snowpack likely lingers in high alpine features. The most suspect locations to trigger this layer would be where the snowpack is thin near rocky outcroppings. Large loads, such as cornice fall, may have the potential to trigger it.

Terrain and Travel

  • Watch for avalanche hazard to increase throughout the day.
  • Make conservative terrain choices and avoid overhead hazard.

Problems

Wind Slabs

An icon showing Wind Slabs

New wind slabs are expected to form with forecast new snow and elevated southwest winds. Recent wind transport from north winds means that both recent and fresh wind slabs may be found on a wide range of aspects on Thursday.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

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 about 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 26th, 2020 5:00PM

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