Vail & Summit County
SnowpackAndrew McWilliams · Dec 20, 2022 · Vail & Summit County
Weather
The day started with a few clouds and the skies became scattered by 11 AM and broken by 2 PM. Single digits in the morning warmed to the teens by noon, but cloud cover kept temperatures from increasing further. Light winds all day; Breckenridge Ski Resort weather stations reported winds from the west, but they were so light it was hard to tell.
Snowpack
More snow and slab than I expected below treeline. At 9500 feet, there was about 30-45cm of snow on the ground with facets near the ground then a distinct slab which varied from 5-20cm thick depending on location. On top of the slab was faceting precipitation particles about 5-15 cm thick. At times this below treeline slab was supportable to skis and as I moved higher in elevation it became consistently supportable. At the near treeline elevation, snow height increased to about 70cm with two distinct slabs above the crusts and basal facets. The top slab was close to the surface from recent strong winds and as I traveled higher, this slab also began to support my skis. Extended Column Test results were non-propagating and hard near treeline on an east aspect. Above treeline, I got propagating results with a hard score in facet/crust combinations nearer to the ground on a southeast-facing slope. A Propagation Saw Test in my above treeline snowpit showed propagation to the end after cutting 35cm. I found no signs of instability like cracks or collapses as I ascended or descended. The snowpack has quieted down and stabilized in the past week, but I think test results show that the Persistent Slab problem is still present and laying in wait for a trigger in just the right location.