New snow and strong winds will be building reactive storm slabs.
Start with conservative terrain and watch for signs of instability.
10 to 25 cm of new snow is expected. Storm slabs will be most reactive in wind-loaded areas, with recent snow currently sitting on a weak surface hoar layer 30 to 50 cm deep. Slabs could be larger than expected if they fail on this layer.
Saturday
A few storm slabs were observed up to size 2.
Friday
Several loose wet avalanches and one slab avalanche up to size 2 were observed.
With more new snow and strong winds in the forecast, the danger is expected to remain elevated with large natural avalanches possible and human-triggering likely.
Observations have been limited by poor visibility and difficult weather, so be sure to post your observations to the MIN if you get out!
Up to 25 cm of new snow is expected to accumulate overnight and through Monday, with potential for rain below 1300 m. Strong southwesterly winds will be loading lee areas.
The new snow will add to the previous 30 to 50 cm that fell over the last week. In sheltered areas, the combined storm snow is overlying a weak layer of surface hoar or facets, over a thick, hard crust. Smaller storm slabs could step down to this layer, creating large avalanches. Rain below 1300 m may have neutralized the surface hoar problem at lower elevations.
The mid and lower snowpack is well settled with no current layers of concern. Treeline snow depths throughout the region range from 150 cm to 250 cm.
Sunday Night
Cloudy. 2 to 10 cm of precipitation as rain or snow at treeline. 40 km/h south ridgetop wind. Treeline temperature -1 °C. Freezing level 1300 m.
Monday
Cloudy. 5 to 15 cm of snow at treeline. 40 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1100 m.
Tuesday
Cloudy. 10 to 15 mm of precipitation as snow or rain at treeline. 60 km/h south ridgetop wind. Treeline temperature 0 °C. Freezing level rising to 1800 m.
Wednesday
Mostly cloudy. 5 to 20 mm of rain at treeline. 70 km/h south ridgetop wind. Treeline temperature 2 °C. Freezing level rising to 2000 m.
More details can be found in the Mountain Weather Forecast.
