Avalanche Forecast

Issued: Feb 15th, 2020 4:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

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Overnight snowfall is uncertain so be ready to dial back your terrain selection if it exceeds forecast amounts. Fresh snow will be eager to shed from steep slopes that see strong sunshine.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Saturday night: Cloudy with flurries bringing 5-15 cm of new snow. Moderate southwest winds.

Sunday: Diminishing cloud and easing flurries bringing up to 5 cm of new snow in the morning. Light northwest winds. Alpine high temperatures around -9.

Monday: Mainly sunny. Light west winds. Alpine high temperatures around -9.

Tuesday: Sunny. Light west winds. Alpine high temperatures around -10.

Avalanche Summary

Slightly enhanced snowfall over Thursday night brought more active avalanche conditions to the region on Friday. Reports showed several natural and explosives triggerd storm slabs reached size 2, with crown fracture depths of 20-40 cm, showing some evidence of wind loading. Northeast aspects above 1900 metres featured most prominently. Several natural cornice falls were another stand-out feature.

New avalanche observations from Tuesday were limited to a few small (size 1) wind slabs able to be skier triggered in crossloaded gully features. Observations into the alpine were limited by poor visibility. Wednesday's reports showed a transition to small dry loose releases.

Looking forward, another night of snowfall

Snowpack Summary

10-20 cm of snow from the past week has been adding to wind-affected snow and old wind slabs in exposed terrain while adding to older, settled storm snow in sheltered areas. Collectively 25-50 cm of snow now overlies a thick rain crust that exists up to roughly 2100 m. In many areas this capping crust extends to mountaintops. 

The bottom 20 cm of the snowpack consists of basal facets and decomposing crusts that have not been an active avalanche problem since December, but could reemerge as a problem after sustained warming.

Terrain and Travel

  • Seek out sheltered terrain where new snow hasn't been wind-affected.
  • Caution around slopes that are exposed to cornices overhead.
  • Be alert to conditions that change with elevation and sun exposure.

Problems

Storm Slabs

An icon showing Storm Slabs

Overnight snowfall is likely to form a touchy new storm slab problem for Sunday. Depending on amounts, the problem may become widespread or instead be focused toward the wind loaded lees of exposed terrain features. Fresh accumulations are likely to shed easily from steep slopes that see sun.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

An icon showing Cornices

Natural cornice falls are a feature of recent reports that will likely increase with sun exposure on Sunday. Cornice falls are dangerous in their own right but they may also trigger avalanches on slopes they impact.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1.5 - 2.5

Valid until: Feb 16th, 2020 5:00PM