North Columbia

Avalanche danger will rise Monday as new snow and wind build fresh slabs. As the storm slab problem worsens, the easy solution is to choose more conservative terrain.

Moderate

• Forecast snowfall amounts are uncertain.
• We are confident the likelihood of avalanche will increase with the arrival of the forecast weather.

Storm and wind slab avalanches were reported size 1 to 2.5 over the past three days, triggered naturally, by humans and explosives. Most were on northwest to northeast aspects at upper elevations.

10 to 25 cm of new snow is expected to accumulate by the end of the day Monday. It falls over settled or wind affected snow from last week.

The prominent mid-December facet/crust layer is buried over 1 m deep and extends up to 2200 m. Triggering the crust is considered unlikely, except with large loads or in thin snowpack areas.

Sunday Night
Cloudy. 5 to 15 cm of snow. 60 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1500 m.

Monday
Cloudy. 5 to 10 cm of snow. 50 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1600 m.

Tuesday
Mostly cloudy. 10 to 20 mm of precipitation as snow or rain at treeline. 40 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1900 m.

Wednesday
Mix of sun and clouds. 1 to 5 mm of rain at treeline. 60 km/h southwest ridgetop wind. Treeline temperature 1 °C. Freezing level 2100 m.

More details can be found in the Mountain Weather Forecast.

• Storm slab size and sensitivity to triggering will likely increase through the day.
• Be especially cautious as you transition into wind-affected terrain.
• Dial back your terrain choices if you are seeing more than 25 cm of new snow.