Avalanche Forecast

Issued: Feb 25th, 2021 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is low. Known problems include Wind Slabs.

Tim Haggarty,

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Explosive control work Wednesday found slabs were reactive in the alpine and into  treeline. Consider human triggering of these slabs to be likely.

Summary

Weather Forecast

Thursday evening will bring up to 5cm of additional snow as the west winds diminish to moderate. Friday winds will shift NW and diminish to light to moderate accompanied by trace amounts of snow temps will reach -3C at 1500m and -15C at 3000m. Saturday will bring an additional bit of snowfall and cooling to -10C at 1500m and -20C at 3000m. 

Snowpack Summary

5 to 10cm of new snow arrived with strong winds Thursday contributing to the wind slabs above the February 19 interface created by 50cm of snow combined with extreme west winds over the weekend. Now down 60 to 90cm,  facets buried Jan 27 provide weak support for the upper snowpack and have been entrained as avalanches gouge down to them.

Avalanche Summary

Wednesday, explosive triggers continued to easily release large avalanches running to the bottom of their paths. This includes large avalanches on Mt Field and Mt Dennis. Results in the Simpson area were limited due to less wind in the area. A skier accidental sz 1.5 on the SW slope between Wolverine and Purple bowl  was reported late Wednesday.

Confidence

Due to the quality of field observations

Problems

Wind Slabs

An icon showing Wind Slabs

Up to 50cm of snow over the Feb 19 interface has proven to be mainly reactive where the wind formed slabs. These extend well into treeline elevations. New snow Thursday has contributed to these slabs but may also bury them, making them hard to detect

  • Use caution in lee areas in the alpine and treeline. Recent storm snow has formed wind slabs.
  • Watch for signs of slab formation.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Feb 26th, 2021 4:00PM