Glassing Ketchum to Banner, roadside Banner obs, Salmon River headwaters avalanche incident

Quick report

A snowmobiler was buried and successfully recovered in the Salmon River headwaters. A swift partner rescue and good fortune lead to a good outcome. Multiple large avalanches released naturally near Galena Summit, and one slide blocked the highway around 6:30PM Friday night. I observed several other natural avalanches that released in the last 24-48 hours. Large roof avalanches were reported in Ketchum during the day Saturday. Evidence indicates that, in many places, the avalanche danger did not drop in the past 24 hours.

Cracking and collapsing are N/A - roadside observations only.

Weather

Air Temp

20s

Cloud Cover

broken

Wind Loading

moderate

Recent Snowfall

0-5cm roadside

Snow Avail For Transport

small smounts

Skies: PC to MC in Boulders and Pios...MC to obscured in the Smokys, Sawtooths, and Banner area. Isolated showers in the western mtns. 5cm (2") of low density snowfall above yesterday's rain crust roadside at Banner Summit and around Galena Summit, much less elsewhere along HWY75 and 21. Wind-loading: Wind had formed lots of ripples/scallops/dunes in exposed middle elevation and upper elevation terrain, primarily above about 8800'. The wind appeared to sift snow onto many slopes above about 8200-8400'. Some isolated roadside drifting near Frostbite Flats and other favored locations in the Boulder and White Cloud foothills.

Snowpack

Banner Summit area 6900-7000': 5cm new snow...then 1cm frozen rain crust...then thin layer FCmf...then 1cm partially frozen rain crust...then 15cm moist/damp snow...then dry DF/PP. The top of the recent rain crust was quite rough, and the new low density snow above did not want to shear cleanly on the crust.

Rain runnels to >7100' around Banner Summit.

Many small surficial WL avalanches in the Stanley foothills.

Quick report

Weather

Snowpack

Avalanche