Avalanche Forecast

A widespread cycle of natural wet loose avalanches occurred with rain in Kootenay Pass on Tuesday. Touchy surface instabilities composed of dry snow were likely widespread at any higher elevations that escaped the downpour.

Looking forward, elevations that saw moderate to heavy rain should see avalanche activity drastically reduce with overnight cooling periods. Areas where new surface crust is very thin and especially where it is absent will likely still harbour upper snowpack instabilities such as wind slabs, or with enough new snow, a more widespread storm slab problem.

By the end of the day Tuesday, parts of the region will see more than 40 mm of precipitation fall. Due to high freezing levels, much of this will be rain with wet or heavy snow at higher elevations. South to southwest winds will likely form wind slabs with the available snow at higher elevations. With enough dry snow accumulation, a more widespread storm slab problem could form.

Whatever dry snow does accumulate will bury awidespread crust, now down 30 to 50 cm, except on north-facing slopes at treeline and above, where the storm snow sits on old, faceted surfaces, and on surface hoar in some sheltered areas.

The mid-pack is generally well-settled.

In some areas, the lower snowpack includes a layer of weak facets near the ground. No recent avalanches have been reported on this layer. However, we continue to track the layer and watch for any signs of it becoming active again.

Tuesday night

Cloudy with continuing convective flurries bringing 5-15 cm of new snow. Light to moderate southwest winds, easing.

Wednesday

Mainly cloudy with isolated flurries and a trace of new snow. Light northwest winds. Treeline high temperatures around -2 with freezing levels to 1500-1600 m.

Thursday

Sunny. Light west winds. Treeline high temperatures around 0 with freezing levels to 1800 m.

Friday

A mix of sun and cloud with isolated wet flurries or showers. Light southwest winds. Treeline high temperatures around 0 with freezing levels to 1800 m.

More details can be found in the Mountain Weather Forecast.

• Make observations and assess conditions continually as you travel.
• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
• When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.