Observation Date: 01/15/2017
Up Little St. Joe, Down north to Sweeney Creek, Up lower portion of Pyramid Butte, then up around the head of the SF Sweeney creek, over pass between Stormy and Big St. Joseph peak, down Bass creek.
Crowns from recent (< 5 days) wind loading on NE face of Big St. Joseph peak and other steep E aspects
During a long tour in the Northern Bitterroot, we made a few avalanche observations. We saw several recent crowns on very steep NE aspects from recent wind loading that ran in the last few days. We also saw old loose sluff debris piles from directly after the January 9-12 snow event. We also skinned over very old debris from the mid-Dec. avalanche cycle at the base of big south facing avalanche paths.
We dug a quick pit only down to 60 cm to assess the wisdom of proceeding upward at the base of the S. face of Pyramid Buttes at about 7,200 feet. South facing, in a wind loaded pocket at the bottom of the gully. Test results were CT5Q1 at 5 cm (new thin wind slab), and CT20Q2 at 40 cm (facets under the January 8th crust). While pit results were reasonably reassuring, we decided to not proceed upward due to uncertainty with how reactive soft slabs would be from the Jan 9-12 snow event on the upper mountain.
We did not have any collapsing all day, and were generally surprised with the good snow structure given the extended period of cold (as opposed to weaker snow structure in adjacent ranges including the Rattlesnake). While we did find weak faceted snow on the surface, well developed surface hoar growth was limited to open areas below about 6,500 feet. Once again, this was in contrast with extensive surface hoar growth observed in the Snowbowl backcountry on 1/14.
Observer: Brian Story