We saw this avalanche on Sunday, February 25 and estimate the avalanche occurred on Saturday or early Sunday morning, likely from a cornice fall. What is interesting is that this avalanche didn't break higher on the slope as it was too steep and graupel from recent storms cascaded down the slope. And the avalanche failed where the graupel accumulated lower down the slope. Graupel is a tricky weak layer, and I often find it can take several days (or longer) to strengthen. The graupel that this avalanche failed on was 4F hard (it is gaining strength) and the wind slab on top was 1F hard. An ECT in the crown yielded ECTP26 down 55 cms. My partner, Chris Dechet, performed an ECT where the slab was thinner and got ECTP14, down 30 cms.

Nikki pointed this out perfectly in her 2/25-2024 forecast under the Wind-Drifted Snow problem: "Some of these wind drifts may be reactive if they formed on top of graupel. The graupel layers vary, but they can often be found below steeper cliff bands where graupel can accumulate."

Below Photo ( Scot H.)