An above freezing layer develops in the alpine on Wednesday promoting settlement in storm snow. Watch for slab development and increasing signs of instability as temperatures penetrate the upper snowpack through the day.
Up to 30 cm of light unconsolidated snow fell Monday night and covered old wind slabs. Rising freezing levels Wednesday will promote cohesion in the surface snow and encourage slab development.
30-50 cm of snow sits above a thick crust. With freezing levels well into the alpine, brief periods of direct sun could produce natural avalanches cycle on surface layers.
30 cm of light unconsolidated snow fell Monday evening. In wind-exposed features at alpine and treeline, new snow covers old wind slabs. 30-50 cm of snow over overlies a thick supportive crust found below 2000 m.
Below this, the snowpack is considered settled. Weak layers exist within the mid and lower snowpack but the thick crusts sitting above them make triggering avalanches on these layers unlikely.
Snowpack depths are roughly 150 cm at treeline and taper rapidly below 1500 m.
A few size 1 avalanches were reported within the storm snow. They were suspected to be wind triggered. Backcountry users should expect to see evidence of a natural storm slab avalanche cycle from Tuesday's surprise storm.
Please continue to share any observations or photos on the Mountain Information Network.
Tuesday Night
Cloudy with isolated flurries, trace accumulation. Westerly ridge top winds 20 km/h gusting 40 km/h. 1500m temperature high of -2C. Freezing levels of 600 m.
Wednesday
Cloudy with sunny periods. Light northwesterly winds occasionally gusting to 30 km/h. 1500m temperature high of +1C. An above freezing layer is present between 1500-2500m.
Thursday
Cloudy with sunny periods. Light northwesterly winds occasionally gusting to 40 km/h. 1500m temperature high of 0C. An above freezing layer is present between 1500-2500m during the day dropping to 800 m overnight.
5 cm of snow is forecast overnight.
Friday
Mix of sun and cloud. Light northwesterly winds occasionally gusting to 30 km/h. 1500m temperature high of -4C. Freezing levels of 1000 m.
More details can be found in the Mountain Weather Forecast.
