Southern San Juan
AvalancheChris Bilbrey · Feb 10, 2021 · Southern San Juan
Weather
Overcast skies with periods of light snowfall and breaks of sunshine. Westerly winds were light throughout the day. We found about 4 to 6 inches of new snow below treeline and up to about 10 inches above treeline. The new snow didn't change stability or conditions where we traveled.
Snowpack
No obvious signs of unstable snow observed. Snowpack remains supportable to skis but stepping out of our skis easily broke through to weaker snow - especially as we climbed into the near treeline elevation band. A snowpit on a north aspect at 11,700 feet revealed a stiffening slab over 4F facets from the December timeframe. Compression test failed with hard force and fracture planes remain planar. It took 27 taps in Extended Column Test for the same weak facets to propagate a failure with unremarkable test results higher up in the snowpack. Pole probing on an open, northwest-facing alpine slope revealed harder layers 12 to 16 inches below the surface that we struggled to punch through. Very little evidence of drifting at higher elevations with snow sitting in trees all the way to treeline. Slopes that face east, southeast, and southwest have a thin and breakable melt-freeze crust below the surface with weak, faceted snow below. Those slopes were not a concern today with the small load above, but may become an issue with a big, quick load.
Avalanche
None observed