Avalanche Forecast

Archived

Apr 1st, 2022–Apr 2nd, 2022

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Purcells.

Expect firm conditions in the morning, softening with sun and warm temperatures throughout the day and watch for wind slabs in extreme terrain. Wet avalanches become more likely on south facing slopes as the surface crust breaks down, and snow becomes wet and heavy.

Confidence

Moderate - Uncertainty is due to the timing of the incoming weather system.

Weather Forecast

FRIDAY NIGHT: Freezing level around 1000 m, trace to 4 cm of snow possible, light southwest wind.

SATURDAY: Scattered cloud with some clearing in the early evening, no significant snowfall expected, light southwest wind, freezing level around 1700 m.

SUNDAY: Broken cloud cover at dawn building to overcast by lunch, a couple cm of snow possible, moderate southwest wind, freezing level around 1700 m. 4 to 8 cm possible Sunday night.

MONDAY: Overcast, 5 to 15 cm of snow possible, strong southwest wind, freezing level around 1700 m.

Avalanche Summary

On Thursday we received two reports of small rider triggered wind slab avalanches on north and east facing terrain in the alpine in the northern portion of the region.

On Wednesday loose wet avalanches were reported on south facing slopes at treeline and below to size 2.5.

On Tuesday, several size 2-3 wet avalanches were naturally triggered by sun, warm temperatures and cornice falls in western terrain near the Bugaboos, with some failing at the ground.

Snowpack Summary

Small pockets of wind loaded snow may sit on north and east facing slopes in the alpine. A crust exists on all aspects as high as 2500 m, softening in the afternoon at all elevations with warm temperatures and sun creating moist surface snow. At very low elevations, the snowpack may be wet and isothermal, depending on overnight freezing levels.

At 30 to 75 cm below the snow surface, a sun crust can be found on solar aspects from March. The recent warm weather seems to have helped this layer bond.

A thick rain crust with facets above from early December is buried around 150 cm deep. Large avalanches were naturally triggered on this layer during the most recent warm temperatures in western terrain near the Bugaboos. Continued avalanche activity on this layer is unlikely with cooler temperatures forecast.

Terrain and Travel

When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
Minimize exposure to sun-exposed slopes when the solar radiation is strong.
Cornices become weak with daytime heating or solar exposure.

Problems

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.