Quick report
- Red Flags
- Recent Avalanches, Heavy Snowfall, Poor Snowpack Structure
Photos of
pit profile showing location of crust (this was taken on a lower-angled slope adjacent to the Grand Central avalanche and highlights the same weak layer);
cornices are quite large!
Over the past 10-12 days, the central Wasatch has received nearly 10' of snow containing nearly 10" of water. We have also had several wind-loading events. Although we have a deep - and what I believe is a generally strong and stable snowpack - there are weak layers within this recent storm snow that are still reactive, and they simply need more time to adjust to this heavy load. The good news is that there is great riding outside of steep avalanche terrain on all aspects and at all elevations.
Snowpack
- Instability Comment
- <p>From what I've seen the past few days, most instabilities within recent storm snow have settled out, but there are some buried weak layers that are still reactive. Today, I focused on aspects facing east and southeast and in a few pits, I was able to get full propagation with extended column tests, failing on a layer of decomposing fragments on top of a suncrust that formed Thursday morning, during a rare period of sunshine. The slab on top is 45-60 cms thick and 4F hard. I was not finding any persistent weak layers - such a facets on top of the crust - so I am expecting this weakness to heal fairly soon, but it clearly still needs some time. (It is also possible there is a thin layer of facets on top of this crust on other slopes - just none that I've seen.)</p> <p> </p> <p>Over the past couple of days, there have been four notable avalanches failing on this weak layer on top of the sun crust:</p> <p> </p> <p><a href="https://utahavalanchecenter.org/avalanche/76239">Weathering Heights</a> - Sunday, March 5 - East aspect at 8,300</p> <p> </p> <p><a href="https://utahavalanchecenter.org/avalanche/76265">Ricardo's Roll</a> - Sunday, March 5 - East aspect at 8,800'</p> <p> </p> <p><a href="https://utahavalanchecenter.org/avalanche/76277">Grand Central</a> - Monday, March 6 - Southeast aspect at 9,000'</p> <p> </p> <p><a href="https://utahavalanchecenter.org/avalanche/76291">Tuscarora</a> - Monday, March 6 - Southeast aspect at 10,600'</p> <p> </p> <p>We typically think of southerly-facing slopes as generally safer than northerly-facing slopes, but this weak layer on top of a crust needs more time to adjust - slopes that seem to have this weak structure are at least east through south-facing, although it is possible this crust is also present on southwest and west-facing slopes.</p>
About 30 cms overnight - settled snow on non wind-loaded slopes since Thursday is now 60 cms in mid-BCC at 9,000'