Avalanche Forecast
Issued: Mar 11th, 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.
William Lawson,
Parks Canada
Great skiing can be found through the forecast region. Keep the avalanche problems in mind while traveling in the backcountry.
Summary
Weather Forecast
Mix of sun and cloud Thursday with temperatures near 0 degrees at valley bottom. Winds will remain in the light to moderate range at upper elevations. A cooling trend will start this weekend as temperatures are forecasted to drop near -25 on Saturday.
Snowpack Summary
10-15cm of snow Wednesday night has been transported by moderate winds at upper elevations creating wind slabs on immediate lee slopes. On steep solar a thin crust has formed on the surface. We continue to monitor the deep, weak facetted snow in the shallower areas of the park.
Avalanche Summary
Direct observation of a natural size 3 cornice release from the postcard face on Cascade mountain. The avalanche ran 1700m to the top of the run out zone. I was difficult to tell if it pulled a slab, though it did entrain a lot of mass in the track.
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.
- 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 12th, 2020 4:00PM
