North Columbia

Another storm will keep avalanche danger HIGH.

Avoid avalanche terrain and overhead hazards.

The ongoing avalanche cycle is expected to continue into Thursday. Since Monday, numerous large avalanches have occurred, including full path persistent slab avalanches up to size 4. Many wet avalanches and cornice failures occurred on Tuesday and Wednesday.

On Thursday, expect a variety of avalanche types due to heavy precipitation and fluctuating freezing levels.

Up to 25 cm of new snow may accumulate by Thursday afternoon as rain switches to snow. This will sit atop wet snow from recent rain and warming.

There is a significant concern for storm slab or wet avalanches stepping down to deeper persistent weak layers. These layers include the early March layer (80 to 120 cm deep) and the mid-February and late-January layers (100 to 200 cm deep), all consisting of surface hoar, facets, or crusts. Heavy precipitation and warming may trigger these layers, as could large triggers like a cornice fall or a smaller avalanche in motion.

Wednesday Night

Cloudy with 0 to 5 mm of rain. 30 km/h south ridgetop wind. Treeline temperature +1 °C. Freezing level dropping from 3000 to 2500 m.

Thursday

Cloudy with 20 to 30 mm of precipitation. Snow line dropping to 2000 m by 10 am, resulting in up to 25 cm of new snow by the afternoon in some areas. 30 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level dropping to 1800 m by the afternoon.

Friday

Mostly cloudy with 5 to 10 cm of snow above 1500 m. 20 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1500 m.

Saturday

Mostly cloudy with 5 to 15 cm of snow above 1500 m. 20 km/h west ridgetop wind. Treeline temperature -2 °C. Freezing level 1500 m.

More details can be found in the Mountain Weather Forecast.

• Only the most simple non-avalanche terrain with no overhead hazard is appropriate at this time.
• Avoid the runout zones of avalanche paths. Avalanches could run full path.