Avalanche Forecast
Issued: Feb 12th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
JSmith,
Avalanche Canada
Avalanches are unlikely in areas where a hard surface crust is present.
Small wind slabs may be found on lee features in the alpine; carefully evaluate steep lines for wind slabs.
Summary
Confidence
Weather Forecast
SATURDAY NIGHT: Mostly cloudy / Light, northwest wind / Low of -3 / Freezing level 1000 m.
SUNDAY: Cloudy with flurries; 3-5 cm, with another 5-10 cm overnight / Light to moderate, southwest wind / High of 1 / Freezing level 1300 m.
MONDAY: Mix of sun and cloud / Moderate, northwest wind / High of -1 / Freezing level 800 m.
TUESDAY: Increasing cloudiness with isolated flurries; 0-3 cm / Strong, northwest wind / High of -3 / Freezing level 600 m.
Avalanche Summary
Explosive triggered cornice failures released several very large (size 3) persistent slab avalanches that likely failed on a crust buried in early February. They occurred northeast of Terrace on Friday. This is a good reminder that large loads, such as cornices or smaller avalanches in motion, can trigger deeply buried weak layers that would be difficult to human trigger.
On Wednesday, heavy precipitation, rising freezing levels, and strong wind caused a widespread natural avalanche cycle up to size 4 (very large). Many professional operators were reporting natural avalanches running full path to valley bottom. In the north of the region, avalanches mostly started in the alpine or treeline as storm or wind slabs, in some cases stepping-down to old weak layers from January and December. In the south of the region, most of the avalanches reported were wet loose, or wet slabs.
Snowpack Summary
5-10 cm of wind-pressed snow overlies a thick rain crust that extends to mountain tops. This crust has created challenging travel conditions and a "slide-for-life" hazard on steep slopes.
Cornices overhead are a primary concern during sunny, warm, or windy conditions. Cornice failures may trigger very large persistent slab avalanches that would otherwise be difficult to trigger.
60-100 cm down, you may find a weak layer of surface hoar crystals, particularly around treeline elevations in terrain features sheltered from the wind. This layer may be also be found as a hard melt-freeze crust at all elevations.
Terrain and Travel
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
- A crust on the surface will help bind the snow together, but may make for tough travel conditions.
- Carefully evaluate steep lines for wind slabs.
- Avoid exposure to slopes that have cornices overhead.
- Cornice failure may trigger large avalanches.
Problems
Wind Slabs
Small wind slabs may be found on lee features in the alpine.
Larger wind slabs may exist in the north of the region at upper elevations where the intense rain on Wednesday fell as snow.
Cornices overhead are a primary concern during sunny, warm, or windy conditions. Cornice failures may trigger very large persistent slab avalanches that would otherwise be difficult to trigger.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Feb 13th, 2022 4:00PM
