Friday January 27 was a stunning bright and bluebird day, with several feet of fresh snow that had fallen the prior eight days. However, six human triggered avalanches were reported that day, primarily in the Park City mountains as well as Lambs Canyon and Summit Park in Parleys Canyon. These occurred in elevations ranging from 7600’ - 9400’ and on northwest through southeast aspects. The weak layers were either preserved surface hoar or near surface facets, buried down 2-3’ in thesnowpack.

Trent produced anexcellent video recapof the avalanche that occurred on Sound of Music in the Park City mountains on the27th. This video describes the persistent weak layer, as well as efficacy of avalanche safety equipment.

On Sunday Jan 29 and well as Tuesday Jan 31, two additional human-triggered slides were reported, one on Murdock Peak on a northeast aspect at 7600, the other in Summit Park on a north aspect at 8200’. Both failed on a layer of preserved surface hoar buried down about 2'.

Otherwise, while the Salt Lake valley was mired in an atmospheric inversion, the mountains were warm and mostly sunny. This extended period of clear weather weakened the snow surface, leaving behind a layer of surface hoar and near surface facets on most sun-sheltered aspects, and a breakable sun and temperature crust on other aspects. Fortunately, moderate to occasionally strong winds early this week, as well as warm temperatures, have seemingly destroyed these weaknesses at the old snow surface. With a few inches of snow from Thursday, and more snow on the horizon, it will be important to evaluate the old snow surface for any preserved weak layers underneath any new snow.

January Alta Guard Summary 8700'(Thanks to MarkSaurer) You didn't just imagine it, January was a snowy month with 154" of snow with 13.3" of water. This is the6thhighest January snow/water on record. (Average is 91.5" with 8.6" of water.)