Quick report
- Red Flags
- Poor Snowpack Structure
- Red Flags Comment
- <p>Am finding weakest layer to be facets just underneath Thanksgiving crust.</p>
First photo illustrates snowpack where the storm snow is a low-density, uncohesive slab.
Second photo illustrates more of a load (45 cms / 18") of storm and wind-drifted snow on top of a thinner crust. I was able to get compression tests to fail in faceted snow beneath this crust. I think this setup is not that widespread, and would be found on upper elevation (> 10,000) northerly aspects that were wind-loaded.
Snowpack
- Instability Comment
- <p>Few pits on northerly aspects between 9500' and 10,300' and it seems Thanksgiving crust was able to support storm load. Storm snow is so low density it is not a cohesive slab & only getting ECTNs above the Thanksgiving crust. I did get one result with a CT in the low 20's that failed in the faceted snow just below the crust. This was on a slope with 45 cms of storm and wind-drifted snow where the crust was much thinner (< 1 cm.) This made me think there may be some upper elevation northerly slopes where the crust is thinner and were wind-loaded that may be suspect where a failure would step into weak, faceted snow below the crust. </p>
Right-side up storm with very low-density powder on top. Would have been a classic day had we a base underneath.
Storm total was roughly 30-40 cms (12-16") in upper BCC, although I did find one wind-drifted area with 45 cms on top of Thanksgiving crust.
Not much of a storm "slab" as it was so light, but generally poor bond to the existing snow surface.
No collapsing and only minor cracking in some pockets of wind drifts.