Avalanche Forecast

Issued: Feb 25th, 2021 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs and Cornices.

Avalanche Canada JSmith, Avalanche Canada

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Recently formed storm slabs will be most reactive in wind affected areas at treeline and above. Be especially cautious as you transition into wind affected terrain.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

  

THURSDAY NIGHT: Snow; 5-15 cm. / Strong, northwest ridgetop wind / Alpine low -10 / Freezing level 600 m.

FRIDAY: Mix of sun and cloud / Light, northwest ridgetop wind / Alpine high -5 / Freezing level 800 m.

SATURDAY: Mix of sun and cloud / Moderate, northwest ridgetop wind / Alpine high -6 / Freezing level 700 m.

SUNDAY: Cloudy with flurries; 3-5 cm. / Strong, southwest ridgetop wind / Alpine high -4 / Freezing level 1100 m.

Avalanche Summary

Explosive control work near Whistler produced storm slabs up to size 2 on Thursday. Storm slabs are expected to remain reactive to human triggers on Friday, especially in wind affected terrain.

Snowpack Summary

Storm slabs formed by 20 cm. of new snow and extreme east/southeast winds have formed touchy storm slabs that are expected to remain reactive to human triggers; especially in wind affected terrain.

The new snow buried a variety of snow surfaces including wind pressed snow in the alpine, sun crusts on solar aspects, and a spotty layer surface hoar in some sheltered treeline areas. The kind of layer that the new snow buried will affect how long slabs will remain reactive to human triggers.

Another weak layer buried in mid-February is composed of a crust, facets or spotty surface hoar depending on elevation/aspect, and is now down 50-80cm. There have been no recent avalanches reported on this layer. Large triggers, such as an avalanche in motion, cornice fall, or intense loading from snow/ wind and/or a rapid rise in temperature can awaken these deeper weak layers.

The mid/lower snowpack is well settled and strong in most areas.

Terrain and Travel

  • Expect slab conditions to change drastically as you move into wind exposed terrain.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Extra caution is needed around cornices under the current conditions.
  • Avoid exposure to slopes that have cornices overhead.

Problems

Storm Slabs

An icon showing Storm Slabs

20 cm. of new snow and extreme east/southeast winds have formed storm slabs that are expected to remain reactive to human triggers; especially in wind affected terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1.5 - 2.5

Cornices

An icon showing Cornices

Cornices are large, looming, and require extra caution under the current conditions.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1.5 - 2.5

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

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