Avalanche Forecast
Issued: Mar 9th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
aaron beardmore,
Parks Canada
A forecasted wind event is expected on Tuesday creating fresh wind slabs.
Summary
Weather Forecast
The high pressure system will start to close out on Tuesday. As this happens wind will increase significantly from the SW in to the strong to extreme range. Snow will start Tuesday afternoon and by Wednesday morning expect up to 15cm. Temperatures will stay in the range of -5 in the valley and -15 at the ridge.
Snowpack Summary
In the alpine the wind is starting to produce soft slabs in lee areas. New sun crusts exist on steep solar aspects. 40-50 cm of recent snow sits over the Feb 29 crust interface on steep solar aspects. In thin snow pack areas a dense mid-pack sits over a weak, faceted base, while thick areas have a stronger base.
Avalanche Summary
Avalanche control on Mt Dennis produced results to size 3 (large cornices that entrain facets and new snow). Evidence of avalanches up to size 3 from the cycle from the past few days in the Little Yoho region.
Confidence
Due to the number and quality of field observations on Monday
Problems
Wind Slabs
This problem has transitioned from a storm slab. The wind is expected to pick up significantly on Tuesday, creating new wind slabs. Expect to find storm slabs in isolated areas as the wind increases.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Recent snow has increased the load on the basal facets and we continue to see occasional results on this layer. Avalanches are most likely in areas with a thin snowpack (<130cm) where the basal facets and depth hoar are the weakest.
- Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.
- Be aware of thin areas that may propogate to deeper instabilites.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 10th, 2020 4:00PM
