Quick report
- Red Flags
- Wind Loading, Cracking, Collapsing, Poor Snowpack Structure
- Red Flags Comment
- <p>We experienced many (>10) localized collapses in upper elevation terrain with small radii (<5m) and 2 notable collapses across entire slopes (>15m). What's worrisome about these crusts is that they are variably supportable—meaning that you can ski along on top of them for long stretches, before dropping down into the weak, faceted snow below and receiving any feedback from the facets below. The grippy nature of the upper crust wind lend well for surface bonding of new, windblown snow, adding more density between you and feedback from the snowpack. This structure is concerning as we continue to build a slab tonight into tomorrow over top this weak structure. This is the type of setup that will allow you to ski well out onto a slope before receiving any warning signs about reactivity.</p>
A huge thank you to Snow Safety Supervisor Seth Burns for spending the day looking at the snow with us, as well the other hard-working folks from Powder Mountain Patrol for having us on a visit.
Snowpack
- Instability Comment
- <p>Nikki, Trent, and I all agreed that we haven't seen facets this wet, but simultaneously this unconsolidated and weak (especially in December). We dug multiple pits, on multiple aspects between NW-N- E, between 8800 and 9000' and kept getting propagation with easy to moderate force on the facets. (ECTP4 x2 & ECTP12) The slab depth and character changed, but the weak layer kept propagating consistently.</p> <p>A strange setup for winter in the Wasatch no doubt, and the temperature patterns throughout and after this storm will largely predict where stability heads for the PWL in the future. For now, a facet, is a facet, is a facet to me. Rounding, wet, damp, what have you. The structure is still there, and while we haven't seen something <em>quite</em> like this before, we do know one thing for certain: <strong>to never trust a facet. </strong></p>
We have new snowfall, on top of a complex of crusts, on top of wet, unconsolidated facets in mid- and upper-elevation terrain. New snowfall was 4 inches of powder when we arrived in the late morning, shifting to graupel by the early afternoon. The new snow fell on top of two variably supportable crusts: (1) a thinner, less stout, grippy, aeroated rain crust from this past week's showers, and below that (2) a thicker, stouter temperature crust from the "meltdown" warm temperatures we experienced prior to this week. Depending on the aspect—and if in wind-exposed or -protected areas—these crusts were either nearly indiscernible or had 2-5cm of wind-drifted mixed form snow between them.