Photos

Eric Knoff investigates a recent natural avalanche on the flanks of Mt Blackmore.  Two other natural avalanches were observed.  This slope received a heavy load of wind blown snow, and the avalanche fractured on a layer of facets about 10 inches off the ground.  A similar layer of facets has been found throughout the Hyalite Canyon area.  Photo GNFAC

This 115cm deep pit was dug on an east aspect at 9,100 feet near Hyalite Lake.  The ECT failed on 21 taps, twice, and broke clean indicating unstable conditions. It is breaking on 5 cm of sugary facets sitting on an ice crust.  Cracking, collapsing and avalanches were seen on this layer in the last 48 hours.  Photo: GNFAC

 Although it was calm in the drainage, winds were cross loading slopes at mid elevations which is where many ice climbs are.  Ridgetop winds were also strong out of the southwest.  Photo: GNFAC

 The Big Sky Snow Safety triggered this slide on the south face with an avalauncher shot.  It broke as a hard slab 2-4 feet deep.  Size was R2D2.5 and failed on depth hoar/facets.  Photo: Big Sky Snow Safety

Collapsing and shooting cracks at 9,600' in the Absaroks are indicative of the instability  throughout southwest Montana. This is bulls eye information that the snowpack is unstable and would likely avalanche on anything steeper than 30 degrees. Photo: Q. Gidley

 This avalanche was released with an avalauncher round.  Rated SS-R2.5-D2.5-O running on facets on or very near the ground. Photo: Big Sky Snow Safety

 Two to four feet deep and ran on facets after getting hit with an Avalauncher round. Photo: Big Sky Snow Safety

On most slopes with a northerly aspect, old snow from several weeks ago has become faceted and is now capped by wind slabs from southerly winds.  Don't trust wind slabs especially in high consequence terrain.  Photo: GNFAC

This small slope had a wind slab resting on top of weak, faceted snow found at high elevation, northerly aspects.  It was used as a test slope, and the wind slab fractured as soon as it was stepped on.  Photo: GNFAC

From an email: "Just wanted to let you know that I observed a decent size avalanche yesterday skiing up in the Mill Creek area. The aspect of the slope was NE, approx start point @ 9922' it ran for 300 yards, approx 100' wide, started as point release but released a 1' deep loose slab on side of chute. The debris pile at the bottom was 7.5' deep." Photo: D. Sene