Quick report
- Cracking
- isolated
- Collapsing
- isolated
Our AIARE 1 course set out to avoid north-facing avalanche terrain and investigate the persistent slab. We found the structure for a persistent slab across northerly aspects in BTL and NTL terrain. We did not observe ATL terrain. Throughout our tour, we triggered a few localized collapses and one slope-scale collapse. The most notable whumpf was a slope scale collapse in NE terrain around 9200' in NTL terrain. We dug adjacent to the collapse and our pit revealed poor stability and likely propagation in the faceted snow at the base of the pack. The 45 cm of new snow provided fun riding conditions on all aspects and improved travel conditions E and SE slopes. While touring across a NE Aspect at 9200' we triggered one slope scale collapse, there was minimal cracking associated with this spectacular whumpf. Throughout the tour, we experienced a few localized whumpfs. Each collapse was accompanied by minimal cracking.
Weather
- Air Temp
- Not Observed
- Cloud Cover
- overcast
- Wind Loading
- none
- Rain Elevation
- Not Observed
- Recent Snowfall
- 45
- Snow Avail For Transport
- moderate amounts
Overcast skies in the am and fluctuated between overcast and broken after 1300. Light east winds with a few moderate gusts, no precipitation, We didn't measure the temperature, but it felt near and slightly below freezing. We saw no blowing snow during our short but comfortable stop at the ridgeline.
Snowpack
We moved uphill of the whumpf we triggered to dive into the snowpack. We dug on a NE Aspect @ 9200' in NTL terrain. There was 45 cm of new snow that ranged from F to 4F/4F+ sitting on top of a thin crust and fist-hard, moist facets. The HS was 75cm. Our pit showed plenty of instability in Compression Tests, Extended Column Tests, and Propagation Saw Tests: CTM-SC@23cm, ECTP4@23cm , PST25/100 (End) @23cm.