A layer of faceted snow capped by new snow and wind deposited snow fractured producing a loud whumph and these cracks that would shoot over 50 feet from our ski tips. Any slope with wind blown snow produced these signs of instability in the Taylor Fork area, and we triggered an 8-12 inch deep avalanche when one slope propagated a fracture for 200ft.
The Bridger, northern Gallatin, northern Madison Ranges and mountains around Cooke City:
Unusual weather normally creates unusual conditions. Extreme cold temperatures and strong winds over the past week have been no exception. The once deep and stable snowpack of the northern ranges has become significantly weaker with thick wind slabs overlaying weak layers of faceted snow.
This photo was taken near the top of the 120m Silken Falls. The avalanche was triggered high in the drainage near the upper ice daggers. The circle represents where we believe the victim was when the avalanche struck.
Eric Knoff stands near the flank 3/4 of the way up the gully that avalanched. 1.5 foot wind slabs broke out from the sides of the gully too.
Mark Staples investigates cracks in the snow near the edges of the gully. The circle shows the crack from the avalanche. The slope above the fracture settled and cracked as we approached. A thick layer of unconsolidated facets was loaded with a dense, 1 finger to pencil hardness wind slab.
Mark Staples is standing where the party triggered the avalanche. It broke another 50 feet higher and was 1 to 1.5 feet deep and 40 feet wide. As the slide moved downhill it released slopes on the side of the gully adding to the volume to avalanche. The slide was a hard slab of wind blown snow.
The Bridger, northern Gallatin, northern Madison Ranges and mountains around Cooke City:
This is the 120m ice flow that the avalanche swept over in Hyalite Canyon. A pocket of wind blown was triggered by a party above which swept Guy Lacelle to his death.
Photo by Luke Koerten who wrote, "Saw this right accross the street from my house. Northwest aspect, thick windslab. Steep slope by Pete's hill standards, maybe 35-40 degrees." Notice the grass poking out of the shallow (1 footish deep) snow in the foreground, yet just a few feet away the depth is 2-3 feet deep of hard slab, wind drifted snow. These conditions are similar to what's up Hyalite in the tight gullies that avalanched and killed an ice climber on Friday.
