Avalanche Forecast
Issued: Apr 19th, 2019 6:22PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Persistent Slabs and Loose Wet.
jesse milner,
Parks Canada
The Icefields Parkway has opened for driving but evaluate what is open for skiing. Up to 30cm of recent heavy snow with winds has created several natural avalanches.
Summary
Weather Forecast
Clearing and cooling off for the next couple days.. A mix of sun and cloud for Saturday with an alpine high of -2 and light westerly winds. Freezing levels dropping to valley bottom Saturday night and mostly clear skies on sunday with cool temps. Winds start to pick up Sunday night as the next system pushes in.
Snowpack Summary
Moderate winds, mild temperatures and up to 30cm of new heavy snow has created widespread storm and wind slabs in the alpine and down into tree line where it was raining below with isothermal snow conditions. A persistent weak layer down 40-70cm (obscured visibility during the storm but we suspect some activity happened on this layer)
Avalanche Summary
A natural loose wet avalanche cycle below tree line up to size 2.5 and several windslabs in the alpine up to size 2.5 in the past 24 hours. Avalanche control on Highway 93 produced several wind slab avalanches up to size 2. We suspect the March persistent weak layer released with the new load but did not observe much terrain due to weather.
Confidence
Due to the number of field observations on Friday
Problems
Wind Slabs
Up to 30cm of new heavy snow has built reactive wind slabs well into the terrain. Wind slabs observed have varied greatly in depth from 20cm to up 60cm thick.
- The new snow will require several days to settle and stabilize.
- Use caution in lee areas in the alpine and treeline. Recent storm snow has formed wind slabs.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Recent snowpack tests and whumphing suggests that a weak layer of facets persists down 40-70cm in some areas. No evidence yet of any activity on this layer during the storm but we expect to see activity once the storm passes and visibility improves.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Loose Wet
A natural cycle up to size 2.5 occurred below tree line during the warm wet storm event. We suspect with the cold overnight temps the problem will not be reactive until it warms up again.
Aspects: All aspects.
Elevations: Below Treeline.
Likelihood
Expected Size
Valid until: Apr 20th, 2019 4:00PM
