Quick report
- Red Flags
- Recent Avalanches, Rapid Warming
- Red Flags Comment
- <p>Although not a red flag category, we have had quite unusual weather which leads to unusual avalanches!</p>
Above 9000' the snowpack seems currently stable. Any old wind drifts are not sensitive, and recent storm snow has consolidated into a relaxed 4F slab. I dug a handful of pits on upper elevation north aspects, and some of these slabs are sitting on top of softer and drier (i.e. weaker) snow, but I could not produce any results with compression (CTN) or extended column tests (ECTX).
The moderate to strong winds were affecting the mid and upper elevations, however, with so little loose snow available for transport, I suspect only shallow pockets of fresh wind drifts can be found.
Am expecting additional snow expected Friday and Saturday will bond well to the old snow surface, and avalanche concerns will be wind and storm slabs.
Photo of skyline. Despite moderate to strong winds, no obvious wind transport was noted.
I was asked by someone "how far back from the edge of a cornice should I be traveling?" My initial answer was - "if you have any doubt, go back even further." But that isn't all that helpful. Part of my tour this morning included traveling along from the top of Patsy Marley to Mt. Wolverine. This traverses across the heavily-corniced Wolverine Cirque, where many cornices are overhanging by easily 15'. The following photos show the corniced ridgeline from the bottom of Wolverine Cirque, as well as a the highlighted route I used for traversing across this ridge.
Very wide berths should be given to corniced ridgelines.
Snowpack
- Instability Comment
- <p>The biggest concern I have right now are the very large and overhanging cornices along many of the upper elevation ridgelines. These cornices have grown quite large through January as we had wind episodes with large amounts of snow available for transport. People are noting some of the largest cornices they have seem for quite some time. Additional layers are being added to these cornices, and several have released naturally, as well as some that have been triggered by surprised <a href="https://utahavalanchecenter.org/avalanches/30378">skiers traveling across a ridgeline</a>. A collapsing cornice is likely to pull back much further from the edge than expected. I currently don't think that if one of these cornices were to collapse it would trigger a large avalanche as the underlying snow is currently stable, the <strong><em>size</em></strong> of these cornices is the biggest concern; it would be similar to tumbling down the slope along with a fleet of Econoline vans.</p> <p>I had noticed a <strong>new</strong>, fresh cornice fall along Patsy Marley ridgeline this morning. I am unsure if it was a natural or if skier had kicked the cornice, but it was another sign of the sensitivity of these large cornices.</p> <p>Stay <strong>well back </strong>from the edge of cornice ridgelines. </p> <p>With more snow and wind in the forecast, this hazard will only increase.</p> <p>The current forecast is showing rain/snow overnight, with continued mild temperatures. However temperatures are also forecasted to decrease on Friday, and turn to all snow. Loose wet snow may still be a problem for Friday morning at the lower and mid elevations, especially if we get more rain than forecasted.</p>
There are a few cms on new, dense snow above about 9500'. The winds kept the snow surface cool on any slope exposed to the winds. Otherwise was finding damp snow on all aspects < 10000'
9500' seems to be the magical elevation between damp snow and somewhat dry-ish snow. I was actually finding decent ski and travel conditions > 10,000'