Avalanche Forecast
Issued: Mar 24th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Loose Wet.
bchristie,
Avalanche Canada
Be thoughtful with your terrain choices, and pay attention to how the weather is affecting the snowpack through the day. Uncertainty about a buried persistent weak layer would make me hesitant to ride a big, committing feature.
Summary
Confidence
Weather Forecast
THURSDAY NIGHT: Partly cloudy. No new precipitation expected. Light southeast ridgetop wind. Freezing level around 1750 m.
FRIDAY: Partly cloudy. No new snow expected. Light southwest ridgetop winds. Freezing level rising to around 2100 m.
SATURDAY: Partly cloudy. No new snow expected. Light south ridgetop wind. Freezing level around 2200 m.
SUNDAY: Mostly cloudy. Light rain overnight, possible snow at high elevations. Light to moderate southwest ridgetop wind. Freezing level rising to 2500 m.
Avalanche Summary
On Tuesday and Wednesday, widespread, loose wet avalanches were reported due to warm temperatures and/or sunshine (size 1-2).
There have been some notable human-triggered avalanches in Kootenay Pass and the Nelson area in the past week. These large slab avalanches (size 2), failed on either a buried sun crust on solar aspects or surface hoar on shaded aspects. On Wednesday, south of Nelson, a large, naturally triggered avalanche was reported that may have failed on or stepped down to this layer. It started on an east through southeast aspect just above treeline.
Snowpack Summary
A skiff of new snow and possibly thin windslabs in the high alpine. Refrozen crust on all aspects up to 2200 m, softening in the afternoon at low elevations and on steep, sunny slopes. Recent warm temperatures, sun, and rain have made the top 10-30 cm of the snowpack moist. Below 1500 m, the snowpack may be wet and isothermal if the freezing levels don't drop enough overnight.
40 to 70 cm below the snow surface, you'll find a frozen sun crust on solar aspects, and weak, feathery surface hoar crystals on shaded aspects. This layer was buried in early March. During the last storm, it produced surprising avalanches in certain areas of the Selkirks (east side of the region). The recent warm weather seems to have helped this layer heal, but it's not yet time to take it out of your danger assessment for the day.
The mid and lower snowpack are generally strong and well bonded.
Terrain and Travel
- If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
- Be alert to conditions that change with aspect and elevation.
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
Problems
Persistent Slabs
This layer is getting harder for riders to trigger, but it is possible that it could still produce large, surprising avalanches.
This layer is a concern where there is a poor bond to underlying surface hoar crystals on north-facing slopes. This problem seems most pronounced in the Selkirks around Nelson and around Kootenay Pass.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Temperatures are forecasted to stay quite steady overnight, and the surface snow may not solidly refreeze at lower elevations. Paying close attention to how thick and supportive the surface crust is throughout the day will help you avoid any lingering wet loose avalanche problems below treeline.
Aspects: All aspects.
Elevations: Below Treeline.
Likelihood
Expected Size
Valid until: Mar 25th, 2022 4:00PM
