Photos

Wind slab around 3-12" deep. NE aspect at 8,000 feet. Occurred sometime on January 8th.

The GNFAC weather station at the top of Sawtelle provides wind, temperature and relative humidity information for forecasting (when it's not covered in a foot of rime ice. Photo: GNFAC

Photo: GNFAC

From the top of Sawtelle. Photo: GNFAC

I observed at least 4 other natural avalanches in the area, not as big but still a tell tale sign to have cautious route finding and avoid slopes steeper than 30 degrees in this mountain range. 

Very large natural avalanche that ripped out on a NE aspect at 9500ft. It propagated hundreds of feet wide and ran approximately 1500ft. The deepest part of the debris pile was ~15-20ft deep. The crown was approximately 3-5ft deep, maybe deeper. 

We did note two small avalanches along the Carrot Basin headwall from sometime in the last two days that broke on weak snow near the ground. These areas looked to have a shallower snowpack. Photo: GNFAC

We did note two small avalanches along the Carrot Basin headwall from sometime in the last two days that broke on weak snow near the ground. These areas looked to have a shallower snowpack. Photo: GNFAC

We did note two small avalanches along the Carrot Basin headwall from sometime in the last two days that broke on weak snow near the ground. These areas looked to have a shallower snowpack. Photo: GNFAC

Riders in the Centennial Mountains experienced almost constant whumphing at higher elevation and saw a couple of days old avalanche on a windl-oaded east north east facing slope. Photo: R. Gravett

A small slide was remotely triggered by the second skier catching up to the first skier. ... We skied to the debris pile after the slide stopped to take a picture and would estimate it broke 30 cm down at the base of the new snow over the last week. Photo: Anonymous

Skiers in the Main Fork of Hyalite Creek drainage spotted this crown below the upper cliffs on the Maid of the Mist. Photo: Anonymous

The Yellowstone Club Ski Patrol noted multiple large avalanches on different bowls and aspects of Cedar Mountain at approximately 9400 feet elevation. Photo: YCSP

The Yellowstone Club Ski Patrol noted multiple large avalanches on different bowls and aspects of Cedar Mountain at approximately 9400 feet elevation. Photo: YCSP

A skier intentionally triggered an avalanche in Argentina bowl below south Saddle Peak. The avalanche broke 2 feet deep and ran 1000–2000 vertical feet piling debris 20 feet deep in the run out zone and breaking trees. Photo: anonymous

A skier intentionally triggered an avalanche in Argentina bowl below south Saddle Peak. The avalanche broke 2 feet deep and ran 1000–2000 vertical feet piling debris 20 feet deep in the run out zone and breaking trees. Photo: anonymous

A skier intentionally triggered an avalanche in Argentina bowl below south Saddle Peak. The avalanche broke 2 feet deep and ran 1000–2000 vertical feet piling debris 20 feet deep in the run out zone and breaking trees. Photo: anonymous

A skier intentionally triggered an avalanche in Argentina bowl below south Saddle Peak. The avalanche broke 2 feet deep and ran 1000–2000 vertical feet piling debris 20 feet deep in the run out zone and breaking trees. Photo: anonymous

On Jan 5 we saw this ~150' wide, 1'deep storm slab in Truman Gulch. GNFAC