John F Stevens Canyon

Quick report

• Traveled into Southern Glacier Park today for a welfare check on the Shed 11 weather station and to collect snowpack data in the BNSF Avalanche Safety Program Area. • All seemed well at the Shed 11 Wx. Looking at the Wx data tonight, digital read outs generally agreed with our manual weather observations near the site. • Took the time to collect pit profile data and conduct multiple stability tests. All results pointed towards instability surrounding our Persistent Slab problem. Structure seems to remain especially poor in this part of the forecast region. See snowpack tab. Recent wind slab avalanches observed on Snowshed Mountain, and our pit location near the Shed 11 Wx revealed unstable results in all four of our stability tests. CT22 Q1, ECTP24, ECTP27, PST 40/115 (END). All test failed on a layer of 0.5mm rounding facets 68cm below the surface.

Weather

Air Temp

-6

Cloud Cover

broken

Wind Loading

Recent Snowfall

Snow Avail For Transport

small smounts

Broken skies with moments of intense sunshine. Solar slopes open to the sky became moist up to at least 5600', A surface crust began to form by late afternoon when cloudy skies and light snow showers returned to the canyon.

Snowpack

• The snowpack at our mid elevation pit site (6448' South Facing) revealed several facet/crust combinations and one particularly talkative weak layer 68cm below the surface. • We conducted four stability tests (Compression, Extended Column Test (2x), and the Propagation Saw Test). All test highlighted the instability of a layer of small (0.5) rounding facets above a thin melt freeze crust. •This worrisome crust is not the Feb 3rd crust associated with a string of near misses across the street near Essex, MT. That much harder crust was located 8 inches (20cm) deeper in the pack. We believe this problematic crust to be one that formed during warm sunny weather on Saturday February 17th (buried 2/19). On all three tap tests, this layer only responded to hard force, but propagated very clean and fast. Additionally, our propagation saw test pointed towards instability. • CT22 Q1, ECTP24, ECTP27, PST 40/115 (END).