Quick report
It was a beautiful day in the mountains. Northerly aspects held cold snow with decent riding conditions. A thin and fragile melt-freeze crust from 12/30 was found on many aspects and elevations.
We found no obvious signs of instability on our tour and the older slabs of wind-drifted snow from earlier in the week appeared to be relatively well-bonded to the interface below. We saw no snow being actively transported. Despite the sunshine, we saw no fresh roller balls nor any other indication that the snow surface warmed or moistened significantly from today's sun.
Our concerns were limited to the upper part of the snowpack from the 12/22 crust complex and up, where there are multiple weak snow/crust combinations which should be monitored as new snow starts to stack up (hopefully).
Weather
- Air Temp
- 28
- Cloud Cover
- few
- Wind Loading
- previous
- Recent Snowfall
- 7 cm
- Snow Avail For Transport
- small smounts
Light winds, cool temps, lots of sunshine. High clouds moved in during the afternoon.
Snowpack
Today we found 4-7 cm of new low-density snow, capped in many locations by 3-5 mm surface hoar. On most aspects and elevations where we traveled, the new snow was sitting on top of a thin melt-freeze crust from 12/30. The exception was above 6200' on a north aspect where the crust was not found. Old frozen roller balls were littered on the surface anywhere a rock or cliff band was overhead, regardless of aspect.
We dug a snow profile on a northeast aspect at 6050 feet wth a slope angle of 30 degrees. The snowpack was 156 cm deep and the upper 38 cm was a 1F wind-drifted slab sitting atop the 12/25 interface (melt-freeze crust). In addition to the 12/25 interface, the 12/22 crust complex (combination of melt-freeze crusts, buried surface hoar, and small faceted crystals) is also a potential layer of concern.
Column tests produced mixed results, with one large column test (ECTP13 @ 118 cm on the 12/25 interface) indicating that propagation could occur. Though we haven't seen any avalanches to date on these layers, a slab sitting on layers with a weak structure warrants some caution and assessment, especially as a new load is added to the mix over the next week.
Below the 12/22 crust complex was a strong layer of 1F rounded grains above the 12/6 AR interface. Below that interface, the remainder of the snowpack was comprised of frozen, hard, and well-bonded melt forms.