Quick report
- Aspect
- South
- Red Flags
- Recent Avalanches, Rapid Warming, Poor Snowpack Structure
- Elevation
- 2621 m
Plenty of wet snow related destruction across the Upper Big Springs and Bunnells drainages on the East side of the Cascade Ridge. The tour provided ample opportunity for group discussions of wet snow avalanche hazard. As a group of three we managed the issues through timing, using a variety of travel techniques, and taking advantage of relatively cooler aspects with transit-able sub-ridges when appropriate. Even still, we occasionally exposed ourselves to slopes capable of producing large avalanches. Bearing witness to the phasic changes of a spring snowpack provided powerful learning for each of us in different ways and it was a good remainder to maintain your ability to be surprised.
Photos:
Big Springs- Bowl 1 Low - Wet Loose
Big Springs Bowl 1 Low- > Human-size roller ball
Bunnells- White Limbo Cliffs and Middle Bowl. One of the cornices along the North Peak is what released and pulled out the hanging snowfield below. Photo at 10am.
Big Springs- Big Bowl 2 - Cornices and Wet Loose
Big Springs- Big Bowl 2 - Skier triggered Sheets of Wet Loose
Big Springs - Big Bowl 2- Numerous Wet Loose, natural and skier triggered
Big Springs - Ridge between Big Bowl 1 + 2- Skier triggered Wet Loose
Big Springs Big Bowl 3 - Old Persistent Slab below rock band had not filled in totally with the last storm
Photo of Bunnells Weather Station
Photo working on Cascade Weather Station
Photo showing the cost of admission
We started the day with a conversation about wind slab potential above treeline, wet slides at all elevations and aspects, and sensitive cornices near the ridgelines. We found wet surface snow and unintentionally triggered one large cornice which proceeded to trigger a persistent weak layer (PWL) avalanche failing in dry snow. Today was a matter of timing and when we ran out of time, we went to very careful route selection and only exposing one person at a time to steeper slopes. Today, started out as a Low danger and rose to Considerable throughout the tour.
Snowpack
- Instability Comment
- <p>With the size of the cornices in this region, traveling underneath or around these behemoths is unsettling at best. See<a href="https://utahavalanchecenter.org/avalanche/95638"> avalanche observation</a> for massive cornice fall triggering a Persistent Slab on a 10,800' East facing slope on North Cascade Peak.</p> <p>The South aspects went off yesterday (3/24) with prolific wet loose. Today (3/25), the East and Southeast followed suit. Natural point releases poured over rocks durnig the late morning. Skier triggered sheets of wet loose running long distances were prevalent by early afternoon. See <a href="https://utahavalanchecenter.org/avalanche/95639">avalanche observation</a> showing wet slab avalanche on a Southeast aspect around 9900'. </p>
Spring transitional. The wetting front of melt water is moving downward into the snowpack, and in the morning it was apparent the radiational refreeze was only 10-20cm deep on South. On East, there was a very thin suncrust/firnspiegel with cold snow below. After today the wet will only drive deeper into the snowpack and start finding preferential drainage patterns, searching for a place to pool and create further unstable conditions.