Avalanche Forecast

Issued: Mar 28th, 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.

Avalanche Canada astclair, Avalanche Canada

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New snow and strong winds may form reactive wind slabs on leeward slopes. This is the final forecast of the season.

Summary

Confidence

Low - Uncertainty is due to limitations in the field data.

Weather Forecast

Saturday night: Cloudy, isolated flurries with trace accumulations, moderate southwest wind, freezing level dropping to 1400 m, alpine temperatures reach -3 C. 

Sunday: Cloudy, 5-15 cm of snow, moderate southwest wind, freezing level climbing to 1800 m in the afternoon, alpine temperatures reach -1 C. 

Monday: Cloudy, 10-20 cm of snow, moderate to strong southwest wind, freezing level climbing to 1500 m in the afternoon, alpine temperatures reach -2 C. 

Tuesday: Decreasing cloud, light flurries overnight, light southwest wind, freezing level climbing to 1300 m in the afternoon, alpine temperatures reach -5 C. 

Avalanche Summary

No recent avalanches have been reported, but mountain travel and field observations are very limited. Recent snow could form wind slabs with the potential to be reactive above the surface hoar that formed over the past week.

Snowpack Summary

Incremental snowfall continues to accumulate at upper elevations. Moderate southwest winds may drift the new snow into slabs on leeward terrain features. This snow sits above a variable mix of crusts, warm snow, and hard old wind slabs. It may also sit above some small surface hoar on shaded aspects. There is some uncertainty about how well the new snow will bond to these interfaces. Weak layers in the upper snowpack have trended towards dormancy. The most prominent and widespread layer was buried in late February and is now 40 to 80 cm deep. This layer was most commonly found in open trees and has produced a few isolated avalanches over the past month.

Terrain and Travel

  • Wind slabs are most reactive during their formation.
  • Avoid terrain traps where the consequence of any avalanche could be serious.

Problems

Wind Slabs

An icon showing Wind Slabs

New snow and southwest winds may form wind slabs in steep terrain at upper elevations. There is uncertainty about how well these slabs are bonding to underlying interfaces.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 30th, 2020 5:00PM