Avalanche Forecast
Issued: Nov 19th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
PW,
Avalanche Canada
As strong winds in the alpine persist, wind slabs will remain reactive. Watch for strong winds and associated slab development locally, on climbs or out sliding on the snow.
It is still very much "low tide" in the Rockies, as Early Season Conditions exist.
Summary
Confidence
Avalanche Summary
We are still receiving reports of recent natural and explosive triggered avalanches up to size 2. The persistent slab will be with us for a while and should be treated with respect. There have been reports of remotely triggering avalanches from 300m away.
Wind slab formation is likely to continue with strong winds in the forecast. These slabs are very likely to step down to the persistent slab if triggered. Pay attention to wind and snowfall amounts locally.
Snowpack Summary
It's still early season with only 30-50 cm at tree-line and 40-80 cm in the alpine. Many early season hazards lurk just below the snow surface.
Wind slab's continue to be sensitive to human triggering. If triggered it is very possible that they step down to the bottom of the snowpack causing larger avalanches.
Lake Louise ski hill reported a new crust from solar activity yesterday on the surface of south and west aspects, below 2500m.
Forecaster have limited observations.
Weather Summary
Winds will continue to be very strong in the alpine down into treeline this evening, through tomorrow. Mild temperatures will persist through the region, as forecaster call for a trace amount of snow overnight. Alpine high is -5C tomorrow, as valley bottoms peak at 0C. Mainly sunny skies on Monday.
For more info, please see the Mountain Weather Forecast.
Terrain and Travel Advice
- Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
- Ice climbers should be equipped with avalanche safety gear.
Problems
Persistent Slabs
Many places with enough snow to avalanche have a weak layer of facets and/or a melt freeze crust at the base of the snowpack. This weak layer is easy to trigger by people or by additional snow or wind loading. Avoiding or minimizing exposure to steep terrain is the best way to deal with this problem.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Small wind slabs up to size 1.5 can be expected in the alpine and exposed tree-line locations. If triggered, this layer may step down and trigger the persistent slab.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 20th, 2023 4:00PM
