Thin Wind Slab and Variable PS structure

CB Avalanche Center 2017-18 Observations

Location: Crested Butte Area
Date of Observation: 01/28/2018
Name: Casey Graham, Chris Martin

Subject: Thin Wind Slab and Variable PS structure
Aspect: North, East, South
Elevation: 9,200-10,200

Avalanches:
Weather: 0deg C for most of the day leading to warming of the surface snow on S aspects, but little change on the Northerlies. Light winds BTL on Snodgrass but blowing snow from NW winds observed in the alpine on the summit ridge of Gothic. Mod. winds on top of Coneys moving some snow down the bowl potentially building the WS near the ridge. Added some wind texture to the skiers left lines and on some isolated cross loaded looking features. Few-Sct clouds all day.
Snowpack: Coney’s: Consistent PS structure observed from the valley floor and up through the trees. HS was around 1m on average. Thin (15cm) WS developed at Ridgeline on the lee – breakable. Multiple CTNs in open meadows near 9700ft and 1 CTH with an SC. The slab in this zone ultimately seems more and more stubborn by the day, but if it does fracture, wide propagation in the terrain seems likely. Lots of tracks pounding the “Nose” and Convex Corner area over convexities with no activity observed.
Snodgrass: Toured from Washington gulch to the saddle between SG and Gothic. Southerly aspects had 8-10cm of soft snow with some surface faceting in the morning on top of 20-40cm of crust/facet layers to the ground. Hot Pow conditions by 1130 on these aspects. N-NE aspects revealed a finicky PS in open terrain at 10,200′ with thickness ranging from 30-50cm of 4F over the garbage V layer which was pretty uniform at 20-25cm. 205-35cm of the light and fluffy on top. CT’s were inconsistent ranging from a few CT12’s with Q1-Q2 SC character to CT30 Q3 RP and an ECTX. HS was 85-95cm with more reactive tests in the former. Ultimately with some digging and probing, the slab was pretty inconsistent and seemed to be eroding across much of the terrain on these aspects.

No big red flags on the day and pretty great ski conditions overall.

Photos: