Carefully poking around up the Kessler shoulder in the trees next to the slabs, on the way up everything felt deceptively solid until ~9600 ft elevation where there was a remarkable shift in snow stability. I noticed weak layer collapse/whoomping but no cracking, so immediately went to transition and descend. While stomping a small platform to transition on, the slope to my east (towards slabs) all collapsed, and then broke free from where I was standing to about 100ft above me, and at least 300ft across. I held onto the tree next to me while the slope ran, transitioned after it slid and then skied carefully down the bed surface. First picture is from the trigger point, second two are of main slide path, fourth is of the next portion further east. I didn't survey the full avalanche area due to safety so width is approximate.

Photo from Davenport

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