Northern San Juan

Avalanche

Colton Frasier · Dec 2, 2023 · Northern San Juan

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Observation photo 1Observation photo 2Observation photo 3

Weather

Obscure to overcast skies for most of the day improving to broken in the PM. Snowfall during our tour ranged from less than 1 cm per hour up to around 1 cm per hour.

Snowpack

New snow 30-35cm (11/30 storm) - some wind affected spots were up 100cm NTL. Variable HS: NTL on Northerlies up to 90-100cm, but also 30-60cm,  ATL 10-60cm (all aspects) evidence of wind scouring. Other aspects S-E shallow and variable HS many rocks/sharks.  It seemed like the latest interface (11/30) was reactive in the snowpits - persistent grain form, but unclear on specifics.  Variety of results in our pit - but mostly consistent fracture character (SC) down 50cm and most results showing propagation or propensity for propagation, but it should be noted the slab was still soft. See specific results. Melt forms on solar aspects - crusts obsereved at base of snowpack in these areas. Test Results: CT12(SC) down 36cm; ECTN down 50cm; PST 50/100 END down 80cm on 20231124; PST 20/100 END down 50cm on 20231130.

Avalanche

Signs of instability seemed widespread in the location we visited. Multiple rolling collapses were observed as well as cracks shooting 30-50ft, our group remote triggered one avalanche and later observed a group remote trigger a slide on the East side of RMP in a zone above the SJMG yurt.