Avalanche Forecast
Issued: Jan 22nd, 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.
Jasper Snow Safety,
Parks Canada
Significant recent wind effect and cornice growth has been observed. Evaluate snow and terrain carefully as large avalanches could occur in isolated areas.
Summary
Weather Forecast
Thursday will be flurries and 8 cm of snow, high -4 °C, Winds southwest 20 km/h gusting to 45 km/h, and freezing level 1700 metres. Friday will be flurries and 7 cm of snow, Low -5 °C, High -3 °C, winds southwest 15 km/h gusting to 40 km/h, and freezing level 1800 metres.Â
For more info: Avalanche Canada Mountain Weather Forecast
Snowpack Summary
The soft surface snow has become more cohesive and is bonding to the previous surfaces as it settles with mild temperatures. The upper snowpack remains mainly facetted. This is pronounced in shallow areas where there is less than 60cm height of snow. There is inconsistent bridging in the mid-pack over the weak basal facets and depth hoar.
Avalanche Summary
Wednesday's helicopter flight observed only two recent large cornice failures that initiated avalanches in the weak basal facets and one windslab avalanche. Tuesday's Icefields and Maligne patrols noted no new natural activity. Monday's explosive work South of the Icefields produced soft slabs to size 1.5 on low elevation targets.
Confidence
Freezing levels are uncertain on Thursday
Problems
Wind Slabs
Winds continue to move the snow around particularly at ridgetop. There was allot of previous wind effects as well.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Avoid lee and cross-loaded terrain near ridge crests.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The likely trigger spot would be from a shallow location. This is a complex problem particularly with our spatial variability across the landscape. Large triggers, such as cornice failures, is enough to trigger this deep instability.
- Avoid convexities or areas with a thin or variable snowpack.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 23rd, 2020 4:00PM
