Quick report
- Red Flags
- Recent Avalanches, Cracking, Rapid Warming, Poor Snowpack Structure
Drizzle Crust from 8,600ft on North aspect in Mill D North.
Drizzle Crust from 8,400ft on SW aspect in Mill D North
Video of a PST from 8,800ft on a NW aspect in Powder Park 3. PST 30/100 (End)
Snowpack
- Instability Comment
- <p>Found the most problematic layer to be 70-80cm down from the surface on NW-N aspects between 8600 and 8800ft in the Milll D North area. These were 2mm facets covered on December 3. </p> <p>This layer gave us variable test results with a number of tests performed:</p> <p>Compression Test (CTM to H BRK, SC), and Extended Column Test (ECTN to P 25-30).</p> <p>However, our results with the Propagation Saw Test proved much more uniform, and a better indication of the instability (PST 30 to 35/100 (End)). This shows us that once initiated, a fracture is likely to propagate. </p> <p>With more loading, this layer we can expect this layer to become more reactive.</p> <p>Associated with terrain features at and near ridgeline. We observed a recent Wind Slab avalanche (D2) off the North side of Desolation Ridge.</p>
Traveling up Mill D North we observed a thin, hard, smooth, and translucent crust coating the surface of the snowpack. As sited below from a research paper by Karl Klassen on the difference between Rime and Freezing Drizzle (<0.5mm water droplets) Crust.
The characteristics of the crust that forms vary depending on the atmospheric and snow surface conditions that exist as the crust forms. Classically, however:
- Hard rime crusts are milky-white and kind of crunchy. - Soft rime crusts are milky-white and more feathery. - Freezing rain/drizzle crusts are hard, relatively smooth, and clear.
"http://www.aspenexpeditions.com/blog/2012/02/03/crusty-crusts-how-mysterious-crusts-form/"