Sawatch

Snowpack

Jason Konigsberg, Drew Gibson · Mar 12, 2023 · Sawatch

Weather

Obscured skies for most of the day with brief bursts of snow as squalls moved through. There were also brief periods of partly cloudy skies, though those did not last.

Snowpack

The snow height in places we dug ranged from 130 cm (below treeline) to over 2 m on drifted slopes near treeline. Even in the shallower snowpack areas, the basal depth hoar has sintered and has some strength. Same with basal faceted crystals. The most concerning layers are buried in between 40 cm and 80 cm from the surface. In most extended column tests we got ECTN results. There were no issues within the new storm snow. We did not identify density changes, and where there was a crust, the new snow seemed glued to the top of it. I think that the recent storm snow was not enough weight, and also not cohesive enough to make upper snowpack weak layers reactive, though I would be wary of very steep east and southeast-facing near treeline slopes. This is where there is additional weight from wind drifting, a more continuous weak layer, and very weak snow under thin crusts. On due south-facing slopes, the melt-freeze crust under the new snow was very strong. It was supportbale even when we were sidehilling with our sleds on 30 degree slopes. There is extremely weak snow under this strong crust but it would take a ridiculous amount of water weight to affect weak layers below this stout crust. ---We saw evidence of heavy, recent cross-loading in northerly terrain. It seems that wind slab avalanches would still be possible just based on looking at the loading patterns. It is hard to say if these avalanches would step down or not. ---There is 40 cm of cold storm snow, so if we see sun and warm temps tomorrow without strong winds, loose wet avalanches are near certain.