Avoid being in or under avalanche terrain.
Intense spring sun and rising temperatures are making large natural avalanches likely.
Cornices are large and looming. With sun and rising temperatures, they may fail naturally, and a large trigger like that could potentially start a large avalanche on a persistent weak layer.
Avoid areas where the snowpack thins, like steep, rocky start zones at treeline and alpine elevations. Weak layers are more easily triggered here.
Freezing levels are rising, and the spring sun packs a punch. Loose moist snow on the surface will get deeper through the day, increasing the chance of loose wet avalanches.
See photos below of large rider-triggered avalanches from Wednesday and Thursday near Fernie. Most notably, one skier was buried in a large (size 2.5 or 3) avalanche that they triggered in a steep, rocky, alpine-like start zone. Luckily they were able to self-rescue, and everyone is ok.
Looking forward, we expect that sun and warm temperatures will make widespread, large, natural and rider-triggered avalanches likely.
In the morning, dry snow may remain at high elevations with refrozen crusts at lower elevations. Through the day, surface snow will start to melt due to intense spring sun and freezing levels forecasted to be well above mountain tops. This loose, melted snow will get deeper into the snowpack as the day goes on.
Cornices are currently large and looming, and are likely to become more unstable during warming. See photo below.
80-150 cm below the snow surface, a widespread crust with weak facets above remains a concerning layer for human triggering, especially during this rapid warm-up.
The snowpack below the crust is generally strong.
Any night-time cooling will be restricted to near valley bottom, the alpine will stay above 0 °C.
Thursday Night
Clear. No new snow expected. Light west ridgetop wind. Freezing level falling to around 1250 m, with above freezing layer forming in the alpine. Treeline temperature around 0 °C.
Friday
Sunny. No new snow expected. Light variable ridgetop wind. Freezing level rising to 2800 m. Treeline high around 4 °C.
Saturday
Sunny. No new snow expected. Light variable ridgetop wind. Freezing level 2900 m. Treeline high around 6 °C.
Sunday
Sunny. No new snow expected. Light northeast ridgetop wind. Freezing level rising to 3300 m. Treeline high around 7 °C.
More details can be found in the Mountain Weather Forecast.
