Avalanche Forecast
Regions: Northwest Coastal.
The storm will bring up to 70 cm by the end of the day on Friday with extreme southwest wind. The avalanche danger will increase throughout the day. Travel in avalanche terrain is not recommended.
Confidence
High - We are confident the snowpack will rapidly lose strength with the arrival of the forecast weather.
Weather Forecast
THURSDAY NIGHT: Cloudy, 20 to 30 cm new snow, 70 km/h southwest wind, alpine low -4 C.
FRIDAY: Cloudy, 20 to 35 cm new snow, 60 km/h southwest wind, alpine high -3 C, freezing level rising to 1000 m.
SATURDAY: Cloudy, 30 to 50 cm new snow, 80 km/h south wind, alpine high +2 C, freezing level 1300 m.
SUNDAY: Clearing during the day, 20 cm new snow, 30 km/h westerly wind, alpine high -3 C, freezing level 500 m.
Avalanche Summary
Several natural glide snow avalanches and loose wet avalanches up to size 2 were reported on Wednesday. Some avalanche activity was observed on southerly aspects on Tuesday during the heat of the day. A few cornices were also triggered, which did not trigger slabs on the slopes below.
Looking ahead, an avalanche cycle is expected to occur in the coming days if the forecast snow amounts hold true.
Snowpack Summary
An incoming storm will bring up to 70 cm new snow by Friday evening with extreme southwest wind. The new snow may overly feathery surface hoar on northerly aspects and in sheltered terrain features around treeline or a melt-freeze crust on southerly aspects and below treeline.
Around 100 to 200 cm overlies a persistent weak layers buried in mid-February that may still be a concern in parts of the region. The layer consists of feathery surface hoar crystals in areas sheltered from the wind and sugary faceted grains that formed during February's cold snap. Avalanche activity on this layer has mostly occurred west of Terrace along Highway 16 in the past week, but the layer could still be of concern anywhere it exists.
There are currently no layers of concern in the mid and lower snowpack.
Terrain and Travel
- Use increased caution at all elevations. Storm snow is forming touchy slabs.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Avalanche Problems
Storm Slabs
The storm will bring 20 to 30 cm new snow overnight and another 20 to 35 cm during the day on Friday combined with extreme southwest wind. In addition, the freezing level is forecast to rise to 1000 m during the day. The new snow will be touchy, especially where it sits on surface hoar on northerly aspects and in sheltered terrain features around treeline or a melt-freeze crust on southerly aspects and below treeline.
The extreme wind will distribute the new snow and may form wind slabs farther down slopes than expected. The wind will contribute to cornice growth.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Almost Certain
Expected Size: 1.5 - 3
Persistent Slabs
Around 100 to 200 cm of snow may overly a persistent weak layer buried in mid-February. The likelihood of triggering the layer may increase in the coming days as the forecast storm rapidly loads it.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 2 - 3