Avalanche Forecast
Issued: Mar 12th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Loose Dry and Deep Persistent Slabs.
Rupert Wedgwood,
Parks Canada
Fresh powder in the trees and out of the arctic wind may be the best option for the next few days.
Summary
Weather Forecast
The arctic air is approaching with an expected 5-10cm of snow overnight in the Icefields area, lesser amount to the north. The winds will switch to the E with this new air mass providing some reverse loading on westerly facing slopes. More detailed forecast at: Mountain weather forecast
Snowpack Summary
The Icefields area has a well bridged midpack overlying basal facets and depth hoar. The northern region is weaker with less bridging midpack above the basal facets and depth hoar.The fridge air will make for weak bonding of the new snowfall.
Sun crusts are largely absent and the melt is evident in the valley bottom with rocks starting to appear.
Avalanche Summary
On Wednesday a field team at the Columbia Icefields noted two Deep persistent avalanches up to size 3.5 on SW & NE aspects in the alpine. Cornices loom large and threatening over enticing terrain below but may also be the trigger for the deep persistent weakness. Spindrift and point releases avalanches have also been observed in the past week.
Confidence
Problems
Wind Slabs
The wind slabs which formed earlier in the week appear to be bonding well. The forecasted new snow for Friday may well form weakly bonded wind slabs with the dramatic temperature drop and easterly winds.
- Use caution in lee areas. Recent wind loading have created wind slabs.
- Assess start zones carefully and use safe travel techniques.
Aspects: North, South, South West, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
There is significant loose snow clinging to rock faces and in steep alpine features. Forecasted new snow will add to this.Triggering of this snow includes wind and solar radiation. Once off and running the debris may trigger deeper instabilities.
- Be careful of loose dry power sluffing in steep terrain..
- Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
2 Large avalanches were observed on March 11th. Initiating this layer is more likely from large loads such as cornice fall or from shallow snowpack areas. In the valley bottom the snowpack is less consolidated with less chance of large releases.
- Avoid shallow snowpack areas where triggering is more likely.
- Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 13th, 2020 4:00PM
