From an email: "As we approached the slope today, we immediately noticed that there wasn't going to be much skiing going on there today- the entire slope had slid. Big. As far as we could tell, it was a natural avalanche and happened within at least the last 24hrs of us being there. There probably wasn't more than six inches of snow left on the slope. Looked like it had possibly been subject to cross-wind loading. The crown varied from 3ft to at least 5ft in thickness. Slope angle varied anywhere from 37º-40º at the crown to around 30º on the southern edge of the slide path.
09-10
This is the crown from the accompanying photo "Bridger Range Natural Avalanche". It broke naturally 3-5 feet deep on facets near the ground. Photo: Jens Anderson
GNFAC Avalanche Advisory for Sat Feb 13, 2010
Snowpack and Avalanche Discussion
The Bridger Range
This avalanche was triggered remotley from the bottom of the slope. This indicates very sensitive and dangerous avalanche conditions. Photo: Aaron Eilers
Forecast link: GNFAC Avalanche Forecast for Sun Feb 14, 2010
2" of new snow and lots of wind from the S-SW made for sensitve conditions on Mt Blackmore. We triggered numerous slopes that were similare to this one. No deep slab releases, but these were easily big enough to drag a person into rocks or over cliffs. Slopes with a N-NE aspect were by far the most active. Photo by GNFAC
Forecast link: GNFAC Avalanche Advisory for Sat Feb 13, 2010
GNFAC Avalanche Forecast for Fri Feb 12, 2010
Snowpack and Avalanche Discussion
The southern Madison Range, southern Gallatin Range and the Lionhead area near West Yellowstone:
GNFAC Avalanche Forecast for Thu Feb 11, 2010
Snowpack and Avalanche Discussion
The southern Madison Range, southern Gallatin Range and the Lionhead area near West Yellowstone:
There are two significant weak layers in the snowpack:
1. Big faceted crystals near the ground.
2. Surface hoar buried 1 1/2 feet deep.
GNFAC Avalanche Forecast for Wed Feb 10, 2010
Snowpack and Avalanche Discussion
The southern Madison Range, southern Gallatin Range and the Lionhead area near West Yellowstone:
Skiers found difficult travel conditions on Electric Peak in the southern Gallatin Range. Unsupportable snow, massive collapsing and shooting cracks gave them all the information they needed to turn around and head home. Photo: Ryan Minton