Avalanche Forecast
Issued: Nov 19th, 2019 4:41PM
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
With a shallow early season snowpack even deep persistent weak layers lurk not far under foot. Be aware that while traveling in the back country you can easily affect all the layers of the snowpack.
Summary
Weather Forecast
A clearing trend is forecasted for the remainder of the week. Wednesday will bring slightly cooler temps before a warming trend returns for the end of the week. Wind values are expected to remain relatively light.
Snowpack Summary
15 to 30cm of winds slab is present on alpine and tree line lee slopes. This wind slab problem overlays several faceted layers in the mid pack. Well developed weak facets near the ground and the Oct crust, have resulted in easy test results in some areas. Treeline snow depths range from 50-80 cm, with up to 110 cm in wind loaded alpine areas.
Avalanche Summary
Lake Louise ski resort continues to report explosive control result to size 2. These avalanches were initiated from wind slab near ridge crest, stepping down to the weak basel layers as they gained mass.
Confidence
Problems
Wind Slabs
Small amounts of new snow and recent strong SW wind on Monday have created wind-slabs in lee areas in the alpine. The wind was strong enough to move snow around at treeline but slab development was less prominent at this elevation band.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Deep Persistent Slabs
The basal facets and Oct crust have been most reactive in the Lake Louise area, but it is likely that similar pockets exist throughout the forecast area. Keep watching for weak areas at the base of the snowpack, especially in steep or convex terrain.
- Convex features and steep unsupported slopes will be most prone to triggering.
- Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 20th, 2019 4:00PM
