Observation Date
12/18/2024
Observer Name
Fotter
Region
Salt Lake » Little Cottonwood Canyon » White Pine
Location Name or Route
White Pine
Comments
We toured up White Pine to 9100' to get a look at the Persistent Weak Layers present in the snowpack and see how they are propagating at middle elevations. We choose a meadow below Columbine Bowl on a NE aspect and upon approaching our dig site, we heard multiple whoomphs as the snowpack audibly collapsed beneath our feet.
We observed:
-Buried surface hoar 24cm beneath the surface yielding the following test results failing on this layer: CT2 SP, ECTP1, a PST propagating to end during isolation, and PST 12/100 End.
-We found buried surface hoar crystals up to 26mm in size(see attached photo).
-This surface hoar sits on top of the 12/13 facet layer and is likely to be found in shaded aspects shielded from the wind
-This surface hoar layer was easily visible as a grey stripe 20-25cm below the surface
-We also observed 1mm surface hoar forming on top of the snowpack from last nights clear skies
-Total snow height where we dug was 71cm
-Winds were light coming out of the NW
-Scattered Clouds
-When in direct sun, it was HOT! We observed the surface wetting on slopes exposed to the sun which may yield a melt/freeze crust tomorrow at middle and lower elevations. We did not travel into upper elevations and did not observe the sun's impact there
While this buried surface hoar problem is found in isolated locations, given our test results, I would give a wide berth to any avalanche terrain that is shaded most of the day and protected from the wind. Thankfully, this layer is easily observable as a grey stripe 20-25cm below the surface.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Coordinates