Avalanche Forecast

Issued: Feb 28th, 2020 1:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is below threshold. Known problems include Wind Slabs.

Avalanche Canada mconlan, Avalanche Canada

Sunny and cold on Saturday, then very stormy. Watch for impact from the sun and recently-formed slabs on Saturday. Best to avoid avalanche terrain and travel very conservatively during periods of intense wind and snowfall thereafter.

Summary

Confidence

Moderate - Uncertainty is due to the track & intensity of the incoming weather system.

Weather Forecast

FRIDAY NIGHT: Cloudy with snowfall, accumulation 2 to 5 cm, light northwest wind, alpine temperature -12 C.

SATURDAY: Clear skies, light west wind, alpine temperature -15 C.

SUNDAY: Cloudy with snowfall, accumulation 10 to 20 cm, strong southwest wind, alpine temperature -8 C.

MONDAY: Cloudy with snowfall, accumulation 10 to 15 cm, moderate to strong southwest wind, alpine temperature -8 C.

Avalanche Summary

There have not been recent observations of avalanches. Watch for small avalanches out of steep, sun-exposed terrain during clear conditions on Saturday. Avalanche activity is expected to increase on Sunday and Monday as the winds howl, rapidly transporting all the recent soft snow.

Snowpack Summary

Around 30 to 50 cm of snow fell in the past few days. This snow will likely remain soft and loose in sheltered terrain but have some slab properties in wind-exposed terrain due to recent southwest wind. The snow may further settle on sun-exposed slopes on Saturday under clear skies. The wind will howl on Sunday and Monday, along with 10 to 20 cm of snow each day. Wind slabs will quickly form.

At White Pass the snowpack is roughly 200 cm thick with a strong mid and lower snowpack. Thin snowpack areas to the east of White Pass may have a lower snowpack composed of sugary faceted grains, capped by a breakable melt-freeze crust and wind-affected snow.

Terrain and Travel

  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.
  • Avoid all avalanche terrain during periods of heavy loading from new snow and wind.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.

Problems

Wind Slabs

An icon showing Wind Slabs

On Saturday, soft slabs may be found in alpine terrain and expose treeline, but loose snow will be found elsewhere, particularly at sheltered treeline. Although Saturday will be cold, southern aspects will see the brunt of the sun, potentially triggering small releases or cornices.

On Sunday and Monday, the recent 30 to 50 cm of snow will get blown around by strong southwest wind, rapidly forming new wind slabs. Natural avalanche activity may occur during periods of rapid snow loading and human reactivity is expected to remain elevated for the coming days.

Aspects: North, North East, East, South East, West, North West.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2.5

Valid until: Mar 2nd, 2020 5:00PM