Avalanche Forecast
Issued: Nov 27th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet.
wlewis,
Avalanche Canada
Danger increases with heavy rain and high winds today. Minimize your exposure to avalanche terrain and overhead hazard as the snowpack becomes saturated and unstable.
Summary
Confidence
High - We are confident the likelihood of avalanche will increase with the arrival of the forecast weather.
Weather Forecast
SATURDAY NIGHT: Another front brings windy and wet weather to the region in the evening. 10-25mm is expected overnight. Snow will become mixed precipitation and rain as freezing levels rise throughout the night, spiking above 2500m by early Sunday morning. Winds increase to extreme southwest winds as the storm progresses.
SUNDAY: Up to 10mm throughout the day with freezing levels remaining above 2000m. Strong southwest winds persist.
MONDAY: Winds shift to moderate westerlies with light accumulations as the storm exits.
TUESDAY: Yet another atmospheric river (moisture heavy weather system) hits the coast and begins to affect the interior. Moderate accumulations, strong winds and high freezing levels return.Â
Avalanche Summary
On Friday November 26, a size 1.5 skier accidental storm slab was reported on the Mountain Information Network near Nelson. They noted a fast moving avalanche with wide propagation, supported by a hard bed surface.
On Wednesday, November 24th, multiple size 2.5 wind slabs were triggered by explosives in the Okanagan. These were reported on wind loaded east and southeast aspects up to 60cm deep.
Note that there are very few field observations in the Kootenay Boundary this early in the season. Backcountry users need skills in assessing conditions and decision making.Â
Snowpack Summary
25mm of mixed precipitation and rain will fall on recent settling storm snow. In the Okanagan a 2mm rain crust may sit between the new and old storm snow.Â
The mid-November crust is down 25-50 cm and is up to 10 cm thick. The lower snowpack is a series of crust and facet layers. At the bottom of the snowpack, up to 20 cm of faceted snow may be found. Snowpack depths at treeline range from 40-100 cm, with alpine depths exceeding 150 cm in areas. Below 1700m, snowpack depths decrease rapidly.
Terrain and Travel
- Be alert to conditions that change throughout the day.
- Avoid avalanche terrain during periods of heavy rain.
- A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
Problems
Loose Wet
Incoming precipitation will fall as a mix of rain and wet snow on recent storm snow to mountain top in most areas. Conditions will rapidly become unstable as the fresh storm snow from the last week becomes saturated.
At below treeline elevations be mindful of overhead hazard as avalanches may run further than you expect.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Nov 28th, 2021 4:00PM
