Deep Creek Surface Hoar - vertical transect

After reading the forecast warning of shallow buried surface hoar in the Saturday 2/4 forecast--with a major impending storm for Sunday 2/5--I dug with students on couple of slopes around Castle Peak but could not confirm any buried surface hoar layer. On Sunday 2/5 during the storm I dug in two small clearings below treeline in Deep Creek and also observed test slope failures near ridgeline but was unable to identify any buried surface hoar layer. The day after the storm on 2/6, I read the observations of colleagues working nearby who did report finding buried surface hoar in a similar area.

My goal today was to see if I could verify observations of buried surface hoar from the SAC and determine it's vertial extent. I decided to return to Deep Creek and dig a series of test pits along a vertical transect from 6600' to the ridge at 8000' in open or lightly gladed terrain on a northerly aspect--were I would expect surface hoar to form.

• Pit 1: 6670' Flat terrain near the creek. Although surface hoar was visible on the snow surface it was rapidly vanishing in sun exposed areas. There was a firm rain crust down 28 cm. No buried SH was found at this site.
• Pit 2: 6804' in a protected small (15 meter) clearing or glade. The rain crust was thicker here, down 29-38 cm. No buried SH was found at this site.
• Pit 3: 7208' in steep terrain in a medium sized (25 meter)  clearing with good sky exposure. The rain crust was still present, down 51-56 cm, but faint and not as icy as the lower pits. No buried SH was found at this site.
• Pit 4: 7553' in a large flat clearing. Buried surface hoar was clearly visible in this pit in a layer from 49 cm down to 50.5 cm down. SH grains visible in the sidewall layer were 7-10 mm. Typical flat surface hoar grains were visible in the pit wall. The grains that I removed for examination resembled depth hoar ziggurats.  There was no rain crust present in this pit.
• Pit 5: 7827' in a 25 degree sloped portion of a large open area. The surface hoar layer was also visible here, down 59cm. It was only a few millimeters thick and would be easily missied if you wern't expecting to find it.