Storm Slab near Mt. Zimmer Yurt

Skiing from Mt. Zimmer Yurt on 12/30 and 12/31, we found two weak layers of small near-surface facets within the new snow at around 30cm and 40cm deep. The layers appeared to be rounding and healing but were somewhat reactive. In our snowpit on an east facing slope at 9,400 feet we got ECTN results on these layers, but in a PST test, the 30cm deep layer collapsed at 30cm into the cut. This made us wary of skiing avalanche terrain and we avoided steep open slopes. We did ski some small isolated steep terrain features and occasionally had this storm slab break off underneath us, but it did not ever propagate beyond steep, convex features such as spines and pillows.

The attached photo shows a small snowboarder-triggered avalanche from 12/31 on a southeast facing slope at 9,000 feet that broke on the 30cm layer and stepped down to the 40cm layer. The intermittent sun on 12/31 seemed to be increasing the reactivity of the storm slab on sun-exposed slopes. The snowboarder was briefly caught in the sliding snow but maintained his footing as the snow washed past him.