Avalanche Forecast

Moderate - Uncertainty is due to the limited number of field observations.

Unsettled weather will continue over the next few days. On Friday, a strong pacific system will move into the northwest ranges bringing strong winds, rising freezing levels, and up to 20 cm of new snow.

Wednesday Overnight: Mainly cloudy with isolated flurries, up to 5 cm of accumulation. Moderate to strong westerly winds.

Thursday: A mix of sun and cloud with isolated flurries. Light accumulation with continued moderate to strong westerly winds at ridgetop. Freezing levels at valley bottom with alpine temperatures around -15 C. 

Friday: Mainly cloudy with the next system incoming. Winds increasing strong to extreme at ridge top from the southwest. Freezing levels rising to around 500-1000m. 5-15 cm of new snow, heaviest in the afternoon and into the evening. 

Saturday: Partially cloudy with light flurries, trace accumulation. Freezing levels at valley bottom with alpine temperatures around -10 C. Moderate to strong southwest winds at ridgetop. 

On Saturday, a size 3 avalanche was reported in the Hankin-Evelyn area, failing near the ground. This has us thinking about the potential for a deep persistent weak layer.

If you do head out in the backcountry, please share your observations to the Mountain Information Network!

10-20 cm of new snow will continue to be redistributed by southwest winds into wind slabs in the alpine and treeline. These new wind slabs overlie older wind slabs from previous southwest winds and a variety of hard, wind effected surfaces. 

Below 1400m, a thin rain crust exists below the new snow. There have been reports of faceting around this crust with recent cold temperatures. A spotty surface hoar layer has been reported down ~100cm in the alpine and treeline. 

An early season crust can be found near the base of the snowpack. It has shown reactivity in the past week with large loads (explosives and cornice), creating large avalanches. We don't know how widespread this problem may be. With recent snow and wind we are definitely keeping an eye on it, and would be avoiding large features and areas with thin to thick snowpack transitions.

Snowpack depth at treeline ranges from 150-200 cm, with higher values in the western part of the region, tapering to the east.

• Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
• Seek out sheltered terrain where new snow hasn't been wind-affected.
• Avoid shallow, rocky areas where the snowpack transitions from thick to thin.