Avalanche Forecast
Issued: Apr 16th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
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Avalanche Canada
High elevations above treeline is where you are most likely to see or trigger avalanches. The data upon which we build this forecast are limited; please assess conditions as you travel and adjust your objectives, terrain choices, and travel techniques to match the conditions encountered.
Localized areas in the south (e.g. Nelson, Kootenay Pass) may receive the most snow overnight Sunday; if Monday morning you encounter more than 20 to 25 cm fresh, increase the local Danger Rating to CONSIDERABLE
Summary
Confidence
Low
Avalanche Summary
No avalanche reports received for since Wednesday. There are few eyes out in the mountains so this doesn't mean there were no avalanches to report.
Wednesday: Storm slabs (80 cm deep) up to size 3 on northwest through northeast aspects at 2100 m and above. Also smaller storm slabs (30 cm deep) were reported running on the crust, but at lower elevations they broke through that crust and entrained wet snow below.
Snowpack Summary
Generally, spring is advancing and the winter snowpack is melting away, at least at most elevations.
High elevation shady slopes with recent dry snow is where slab avalanche problems are most likely. This snow rests on a widespread crust; the exception is on north-facing alpine slopes where the storm snow could be sitting on old faceted surfaces, and on surface hoar in some sheltered areas.
Elsewhere, a thick rain crust or settled moist snow exists at the surface. Avalanche danger will be closely coupled to daytime warming and melting. The more the crust weakens, and the deeper the wetness goes, the greater the hazard from wet loose avalanches.
The mid-snowpack is generally well-settled. In some areas, the lower snowpack may have a layer of weak facets near the ground.
Weather Summary
Sunday Night
Cloudy with periods of snow; accumulations around 5 - 15 cm; the most snow is forecast around the Kootenay-Boundary area (e.g. Nelson). Freezing level around 1000 m. Wind moderate to strong from southwest.
Monday
As the storm winds down most of the day should see a mix of sun and cloud. Flurries with only an trace accumulating. Freezing level climbs to around 1700 m and alpine temperatures around zero to -5 C. Light, gusting to moderate, southwest winds.
Tuesday
Cloudy with sunny periods and light snow. A trace to maybe 10 cm in localized snow holes. Freezing level climbs to around 1600 m and alpine temperatures around - 5 C. Light southwest winds.
Wednesday
Cloudy with sunny periods and isolated flurries. Only a trace of new snow. Freezing level climbs to around 1700 m. Alpine temperatures zero to -5 C. Light wind.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Make observations and assess conditions continually as you travel.
- Be alert to conditions that change with elevation and sun exposure.
- Snow is accumulating at higher elevations despite lower elevations being almost snow free
- Expect slab conditions to change drastically as you move into wind exposed terrain.
- Keep in mind the crust offers an excellent bed surface for avalanches.
- Minimize exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
Problems
Storm Slabs
With less than 15 cm of new snow forecast Storm Slab avalanche should be small and hard to trigger. Localized areas with more snow may be more reactive and larger. South and southwest wind may form deeper, more reactive deposits of wind slab on leeward slopes.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 17th, 2023 4:00PM
