Avalanche Forecast
Issued: Feb 19th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
jpercival,
Avalanche Canada
Choose terrain that is sheltered from the wind to find the softest snow, and the lowest avalanche danger.
Summary
Confidence
Moderate
Avalanche Summary
On Sunday in the backcountry near Big White, a skier accidently trigger a large (size 2) slab avalanche. This avalanche sympathetically set off a 100 m wide additional slab propagation and subsequently a settlement crack was observed and estimated to be 1 km in length.
In general, small, human-triggered wind slab avalanches continue to be reported In alpine and open treeline terrain. Most of these avalanches are 20 cm deep or less. See pictures below.
Snowpack Summary
Alpine and open treeline terrain are generally wind-affected, with reactive wind slabs in some places. At the surface in most areas, surface hoar is forming in wind protected terrain. Around Nelson and in the Valhallas, small (5 mm) surface hoar (weak, feathery crystals) have been reported to be buried 15-20 cm below the snow surface.
Facets (weak, sugary crystals) are starting to form above a thick rain crust that was buried in early February. This crust is now 30 to 50 cm below the snow surface.
The mid and lower snowpack presents as settled, with snowpacks depths decreasing rapidly on terrain below 1000 m in elevation.
Weather Summary
Monday Night
Mostly cloudy. 1-5 cm of snow expected. Light variable ridgetop wind. Treeline around -4 °C. Freezing level 1000 m.
Tuesday
Mostly cloudy. 1-5 cm of snow expected above 1000 m. Light southwest ridgetop wind. Treeline temperature around -4 °C. Freezing level expected to maintain @ 1000 m throughout the day.
Wednesday
Mostly cloudy. trace amounts of snow expected. Light southwest ridgetop wind. Treeline temperature around 0°C. Freezing level at valley bottom overnight, rising to 1600 m through the day.
Thursday
Mostly cloudy. trace amounts of snow expected. Light southwest ridgetop wind. Treeline temperature around 0°C. Freezing level at valley bottom overnight, rising to 1600 m through the day.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Start with conservative lines and watch for clues of instability.
- Even a small avalanche can be harmful if it pushes you into an obstacle or a terrain trap.
Problems
Wind Slabs
Expect to find wind slabs below ridgecrests, on convex slopes in open terrain, and in cross-loaded features.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 20th, 2024 4:00PM
