Avalanche Forecast
Issued: Nov 20th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
CG,
Avalanche Canada
A sudden rise in Alpine temps, coupled with sunshine and strong winds, may spike the avalanche danger, especially on sunny slopes.
Early season hazards exist everywhere.
The Winter Permit System started on Nov 16! Take the quiz, get your annual permit, and know what areas are open before you venture into the backcountry.
Summary
Confidence
Avalanche Summary
Several small natural avalanches were observed in the hwy corridor off Tupper and MacDonald, ranging from sz 1-2, all from steep to extreme terrain. A field team observed a sz 2, failing on the ground, near Christiana Ridge from a very steep SE aspect, likely from Sunday.
Snowpack Summary
The height of snow at treeline is ~90cm. A thin crust on steep solar aspects has been buried by 5-10cm of new snow.
The base of the snowpack consists of weak, sugary facets and may collapse in shallow, rocky zones, producing large "whumpfs". Snow depth increases with elevation but distribution is highly variable; expect many rocks/trees lurking at and just below the snow surface.
Weather Summary
Warm air aloft will arrive Tues, with a hot pocket sitting between 2000-3000m. Temps will be below 0*C at valley bottom, while rising to +3*C in the Alpine. Winds are expected to be 40-65kph from the West.
The warm pocket will diminish Wed, with normal temps and light snow forecasted.
Detailed weather forecasts can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
Problems
Wind Slabs
New snow and strong southerly winds have formed pockets of fresh wind slab. If triggered, it may step down to the faceted layer at the base of the snowpack, resulting in a large avalanche.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
The facet layer at the base of the snowpack is more likely to be triggered in shallow, rocky areas, such as ridge-crests and open, convex slopes. A bridging crust exists below Treeline, preventing folks from sinking to the ground at lower elevations.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 21st, 2023 4:00PM
