Gallagher Head Lake

Our efforts to gather upper-elevation snowpack data in the Salmon La Sac were thwarted once again by lingering obstacles left by the atmospheric river events earlier this month. Nonetheless, we were able to add a data point regarding the layering of the snowpack at middle elevations and observe signs of surface warming on sunny slopes.

We observed a few small point releases on the south-southeast side of Hawkins. We also saw extensive rollerballing on other southerly facing slopes that were open and exposed to the sun. Snow on trees exposed to the sun was falling in small chunks throughout the day.

The snowpack is still quite shallow at lower elevations and has kept folks from sledding through the trees in a lot of this terrain. With the temperature inversion however, the snow on all aspects has stayed soft and dry. Widespread surface hoar development was observed.

I dug a pit on a NW aspect at 5800 ft. The depth of this pit was 183cm (72in). I found 2-3mm grains of surface hoar at the surface. There is a deep slab (86cm (34in)) of recent snow that has all settled except for about 20cm (8in) at the top. This slab sits on the crust formed on Christmas Eve. Below this are rounded grains, the 12/18 crust, and basal crusts/ice from the AR events earlier this month of increasing hardness. I did not find facets around any crusts. I performed a compression test and got a hard resistant result within the top slab at a density change (CT23PC down 32cm). I performed an extended column test and got a hard non-propagating result at the same interface (ECTN22 down 32cm). I also got a hard shovel shear result at this interface as well (STH).