Avalanche Forecast
Issued: Nov 18th, 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.
MH,
Avalanche Canada
Increasing wind and new snow will gradually elevate the avalanche hazard over the day. Watch for wind slab formation in the Alpine and open areas at treeline.
Early season hazards exist everywhere.
The Winter Permit System started on Nov 16! Get your permit and know what areas are open before you venture into the backcountry.
Summary
Confidence
Moderate
Avalanche Summary
Several natural sz 2.0 avalanches were observed Friday in Lone Pine, Single Bench, Lens, Cougar Valley and Gunners 2. Daytime warming and solar input also released small point release avalanches on solar aspects.
On Thursday, the West face of Cheops produced a sz 2.0 persistent slab and several loose dry avalanches on steep North facing terrain. Artillery control (gun site verification) produced results up to sz 2.5 on steep North facing terrain on Mt. MacDonald.
Snowpack Summary
The height of snow at treeline is ~80cm. A thin crust may have formed on steep solar aspects and will be buried by the incoming snow.
The bottom of the snowpack is facetted and offers little support to the shallow snowpack, often settling and 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
Sunday we can expect 5-10cm of new snow with 25-40kpm Westerly winds with temps dropping down to -13 in the Alpine.
Monday, winds will drop slightly and temps begin to rebound.
Tuesday will see 30-60kpm winds in front of a small pulse of snow.
Detailed weather forecasts can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- 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.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Problems
Wind Slabs
Up to 10cm of new snow and strong Westerly winds may form fresh wind slabs by the end of the day on Sunday. If triggered, they may step down to the persistent layer at the base of the snowpack, resulting in a large avalanche.
Aspects: North, North East, East, South East.
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 19th, 2023 4:00PM
