Quick report
- Collapsing
- widespread
Due to the inversion at freezing rain, snow at higher elevations (above approximately 4000') had a thick, stiff crust above approximately 2 feet of unpacked snow. Weather conditions were clear and mostly sunny. We were not equipped to take measurements, but it was noticeably warmer at higher elevations, with the temperature changing abruptly around 4000'. At higher elevations, freezing rain had coated snag trunks about a quarter inch thick with ice, which was falling off as the sun melted it. We stayed on the groomed road, and turned back when we observed the recent avalanches and snow cracks described above. At lower elevations trees were coated in thick snow, and the snow surface was mostly soft with at least 2 feet of fresh snow. Snow at higher elevation, especially in exposed areas, felt very unstable.
Avalanche
Multiple recent avalanches observed on the north and north-east slopes of the ridge above OR-242 (McKenzie Pass Scenic Highway) around milepost 82 at approximately 4700' elevation. Between 44.2971, -121.7441 and 44.2949, -121.7511 the road cut passes under a very steep (>45 degrees in places) slope around a curve. The slope was heavily forested but burned several years ago, leaving many snags and unvegetated ground. There were large visible cracks in the snow running approximately 20 ft below the top of the ridge. There were signs of recent avalanches on the slope, with large sections of slabs that had broken loose, maybe 300+ feet wide. Difficult to estimate depth from a distance, but approximately 8". The avalanches likely occurred sometime during the day on Saturday, and appeared to be natural. The Mt Jefferson Snowmobile Club had groomed the road from the snopark at NF-1028, and stopped about 3/4 of the way across the road cut and turned around due to avalanche debris. We spoke to a member of the club at the snopark who knew the grooming crew, and he reported that the large avalanche across the road was seen by them on Saturday night when grooming, and that their groomer had previously been caught in an avalanche it triggered in that same location sometime last year.