Toured out to Frazier Basin and turned around seeing widespread avalanches and active wind loading. Despite our pits on the Throne the day before showing no weak layers, the amount of wind loading and potential for slabs over density changes gave us pause. Good skiing and sledding down low.
From IG - "Toured out to Frazier Basin and turned around seeing widespread avalanches and active wind loading. Despite our pits on the Throne the day before showing no weak layers, the amount of wind loading and potential for slabs over density changes gave us pause. Good skiing and sledding down low."
As we approached our second pit site on the lip of Moto Hill (southeast aspect at 8600'), I stopped and looked back in time to see avalanche debris slamming into the trees on a connected slope below. We remotely triggered the avalanche from 150 feet away. It broke 200' wide and 1-3 feet deep. It ran an estimated 200' vertical feet (based on a slope map. We couldn't safely access the toe of the debris). The avalanche failed on a layer of Fist hard facets. This is interesting because it is these mid-elevation slopes in the LH area that seemed really weak on previous visits to the area. The slope may have some wind-loading, but it was minimal and not the cause of this avalanche.
We dug a pit on an east aspect around the corner and down from Airplane Bowl (before the avalanche) and found a similar snowpack setup. 150 cm of total snow and half was composed of weak facets. ECTP22 and P24 on the mid-pack January layer of Fist hard facets and surface hoar.
Take Homes:
Mark, Dave and Brian DiLenge from IDPR rode up Denny Creek and out across below Lionhead Ride. Fog and low clouds made visibility tough but we bounced along the treelines and felt our way across to Moto Hill and back.
Important stuff first. As we approached our second pit site on the lip of Moto Hill (southeast aspect at 8600'), I stopped and looked back in time to see avalanche debris slamming into the trees on a connected slope below. We remotely triggered the avalanche from 150 feet away. It broke 200' wide and 1-3 feet deep. It ran an estimated 200' vertical feet (based on a slope map. We couldn't safely access the toe of the debris). The avalanche failed on a layer of Fist hard facets. This is interesting because it is these mid-elevation slopes in the LH area that seemed really weak on previous visits to the area. The slope may have some wind-loading, but it was minimal and not the cause of this avalanche.
We dug a pit on an east aspect around the corner and down from Airplane Bowl (before the avalanche) and found a similar snowpack setup. 150 cm of total snow and half was composed of weak facets. ECTP22 and P24 on the mid-pack January layer of Fist hard facets and surface hoar.
Take Homes:
From SnoWest Forums FB Page:
“Just getting word of a LARGE Remote Rider Triggered Slab Avalanche down inside of Black Canyon itself just off the Black Canyon Loop Trail in Island Park.
A 3-4ft thick slab broke loose and filled the bottom of the canyon with 12-15 FEET of debris, completely blocking off the canyon itself. Rider was NOT caught in it!! Had the rider been caught, there would have been ZERO chance of rescue under such a deep slide!”
From SnoWest Forums FB Page:
“Just getting word of a LARGE Remote Rider Triggered Slab Avalanche down inside of Black Canyon itself just off the Black Canyon Loop Trail in Island Park.
A 3-4ft thick slab broke loose and filled the bottom of the canyon with 12-15 FEET of debris, completely blocking off the canyon itself. Rider was NOT caught in it!! Had the rider been caught, there would have been ZERO chance of rescue under such a deep slide!”
From SnoWest Forums FB Page:
“Just getting word of a LARGE Remote Rider Triggered Slab Avalanche down inside of Black Canyon itself just off the Black Canyon Loop Trail in Island Park.
A 3-4ft thick slab broke loose and filled the bottom of the canyon with 12-15 FEET of debris, completely blocking off the canyon itself. Rider was NOT caught in it!! Had the rider been caught, there would have been ZERO chance of rescue under such a deep slide!”
