Three skiers were caught in an avalanche in the South Lake Tahoe, California backcountry yesterday. The party triggered a north-facing wind slab on Mt Tallac in the Desolation Wilderness area which includes Emerald Bay. While skinning up, they triggered a size D1 avalanche that caught the 3 skiers and took 1 of the skiers for a 500-vertical-foot ride down the slope and partially burying him. Luckily, nobody was injured. Their avalanche accident report can be found on the Sierra Avalanche Center website.

Full Mt. Tallac, CA Avalanche Report

by Sierra Avalanche Center:

Winds blowing hard out of the East from AM into PM. Partly to mostly cloudy with strong sun between breaks in clouds. 50 degrees at lake level and steadily dropped into mid 30s as group of four skiers gained elevation into near and then above tree-line zone. Lots of noticeable snow transport via wind on skin up to summit, loading from east aspects onto north. As the group skinned from the upper saddle heading east across the upper north face to gain final summit three skiers triggered a loaded north facing slab. 2 skiers were pushed out of the side of the slab avalanche. While 1 skiers who lead the skin across the north face was pushed 500′ down slope in a D1 size slab. Avalanche partially buried skier, fortunately wide bowl and no terrain trap or bench. Skier was able to self rescue.

Afterwards, Near Tree-line on skiers right decent of north facing slopes well below main bowl, big pinball snowballs were moving down slope indicating UV heating and potential sides. Some D1+ size loose wet avalanches were skier triggered and made way thru terrain gullies. Ample snow moving with solar heating.

— Sierra Avalanche Center 04.09.20

Avalanche Details:

Avalanche Details

Avalanche Type: Wind Slab

Failure Plane/Weak Layer: New/old snow interface

Trigger

Trigger: Skier

Trigger Modifier:  Accidentally Triggered

Terrain

Start Zone Slope Angle:  35 degrees

Aspect: North

Starting Elevation:  above-treeline:

Size

Destructive Size: D1 Relatively harmless to people.

Relative Size: R3 Medium

Crown Height: 3 ft

Avalanche Width (Average width): 50ft.

Avalanche Length (Vertical Run): 500ft.

People Involved

Number of people caught: 3

Number of partial burials: 1