Avalanche Forecast
Issued: Mar 10th, 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.
Grant Statham,
Parks Canada
Another pulse of snow over the region will add another 15 cm to the snowpack, again with strong winds making windslabs in leeward areas. Generally a strong snowpack with few natural avalanches, but watch for triggering small slabs near ridge crests.
Summary
Weather Forecast
A system moves through the area starting end of the day on Tuesday that will deposit 10-15 cm of new snow across the park, accompanied by strong westerly winds. Temperatures on Wed will continue in the -5 to -15 range. The snow will continue through until Friday when the temperature drops for a short blast of -25 on the weekend.
Snowpack Summary
Moderate to strong winds on Tues and overnight Wed will have blown snow and created small windslabs directly beside ridge crests that are prone to human triggers. In some areas, this snow overlies buried sun crusts formed in late February. We continue to monitor the deep, weak facetted snow in the shallower areas of the park.
Avalanche Summary
The ski resorts reported easy ski cutting of 10-15 cm windslabs (size 1) formed through the day on Tuesday and observed a cornice fall in very steep terrain that triggered a size 2 windslab on the slope below.
Confidence
Problems
Wind Slabs
It is possible to trigger a windslab in the immediate lee side of ridge crests, but unlikely these slabs will release naturally. Reports from today suggest the windslabs disappear once off the ridges and down onto more sheltered terrain below.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
This problem is the sleeping giant who remains asleep right now until a significant change wakes the giant up again. Avalanches are most likely in areas with a thin snowpack (<130cm) where the basal facets and depth hoar are the weakest.
- Be aware of thin areas that may propogate to deeper instabilites.
- Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 11th, 2020 4:00PM
