Avalanche Forecast
Regions: East Island, North Island, South Island, Vancouver Island, West Island.
During periods of high hazard, avoid all avalanche terrain.
Snow, extreme winds, and rain will rapidly destabilize the snowpack.
Confidence
Moderate
Avalanche Summary
Looking ahead, we expect a large natural avalanche cycle to occur with snowfall and extreme winds, followed by rain.
On Thursday, explosive controlled wind slab avalanches up to size 2 occurred in steep, north-facing terrain. Some stepped down to the early March crust, up to 1.5 meters deep.
On Monday, a large slab avalanche (size 2.5) was triggered by a cornice fall on a north-facing alpine slope on Mount Cain. It was triggered by a person stepping very close to the cornice.
Snowpack Summary
10 to 40 cm of snow overnight will then be saturated by 15 to 40 mm of rain throughout Sunday. This precipitation is accompanied by strong to extreme southwest winds, so we anticipate deeper deposits on north and east-facing slopes. This sits over 60 to 90 cm of recent storm snow.
A robust crust, formed in early March, can be found in the mid-pack. The snow above is well bonded to this crust.
Below this, the snowpack is well consolidated and strong.
Weather Summary
Saturday Night
Cloudy with 10 to 40 cm of snow, greatest amounts in the southwest. 70 km/h southwest ridgetop winds. Treeline temperature -2 °C.
Sunday
Cloudy with precipitation switching from snow to rain, 15 to 40 mm, greatest amounts in the southwest. 70 to 90 km/h southwest ridgetop winds. Treeline temperature rising to 3 °C. Freezing level rising to 2000 m.
Monday
In the overnight period, 5 to 30 mm is expected, falling as snow above 2000 m.
Cloudy with 10 to 30 mm, falling as snow above 1500 m. 70 to 90 km/h southwest ridgetop winds. Treeline temperature 4 °C.
Tuesday
Cloudy with 5 to 10 mm, falling as snow above 2000 m. 50 km/h southwest ridgetop winds. Treeline temperature 4 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.
- Cornice failures could trigger large and destructive avalanches.
- Only the most simple non-avalanche terrain with no overhead hazard is appropriate at this time.
Avalanche Problems
Storm Slabs
Storm snow and strong to extreme southwest winds will form touchy storm slabs. Expect to find deeper and more reactive deposits on north and east aspects at upper elevations, where the wind will load lee slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1.5 - 2.5
Loose Wet
Rain up to 2000 m will rapidly destabilize the snowpack.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood: Likely
Expected Size: 1 - 2