Quick report
- Cracking
- specific
- Collapsing
- Observed
Today, with new snow on the ground, I returned to Gray Butte in search for buried surface hoar and storm/wind slab instability. I quickly found all of the above. The new snow is relatively heavy and dense, cracking on steep slopes with a ski cut. Wind drifted snow has accumulated on northerly aspects near ridge tops and open slopes. Combine the wind accumulations with the new snow, and these slabs were well over a foot deep. Lastly, the surface hoar has been buried and partially preserved under the new snow. One test slope initiated by a ski cut failed on this surface hoar layer, propagating above the ski cut. This “layer of concern” has the potential to increase in sensitivity and destructive size with increased loading.
Cracking was observed along steep slopes within the new snow, as well as on leeward ridges. Wind drifted snow was visible on northerly aspects. Surface Hoar (SH) that had formed over the last few days was identified below the new snow. Upon compression test, failures occurred on stellar dendrites and the buried SH on taps 4 and 5.Weather
- Air Temp
- 24
- Cloud Cover
- obscured
- Wind Loading
- moderate
- Rain Elevation
- 3,000
- Recent Snowfall
- 23
- Snow Avail For Transport
- large amounts
Heavy snowfall with obscured skies and poor visibility. Temperatures were close to freezing at 5,500 feet, becoming well below freezing above 7,000 feet.
Snowpack
- New Snow: Eight to ten inches of new snow has accumulated across Gray Butte.
- Buried Surface Hoar: Surface hoar that formed over the previous cold days has been buried beneath the new snow. The distribution of this grain is fairly specific and inconsistent. Unfortunately, surface hoar is a weak grain, incapable of holding much weight before failure. This layer will need to be watched over the coming days. Upon compression test, this layer did fail under light taps.
- Wind Loading: Obvious wind loading was observed on northerly aspects, with ample amounts of soft snow available for transport.
- Snow Quality: Below 6,000 feet, the snow is wet, heavy, and sticky. Snow quality becomes colder and drier with higher elevation, becoming exceptionally dry near 8,000 feet. Boot penetration was waist deep!
- Snow Depth: On a southeast aspect around 7,800 feet, averaging at 340 cm (134 inches).