Near Miss Cornice Fall, The Checkerboard

Traveled up the Noisy Basin Road and Switchback Trail to the top of the Checkerboard looking for wind slabs.

• We stomped on many small cornices above test slopes. Cornices were hard to get to release and did not trigger any slides. But as we skinned north along the ridge to the Checkerboard we noticed cracks opening near the root of large cornices. We took a healthy step back, but as we continued up the ridge a cornice failed at our feet - 10' back from the edge. The cornice was about 40' lond and 12' thick. It triggered a large wind slab avalanche on the steep slope below.
• We measured wind drifts between 10" and almost 3' thick near ridgelines on northwest, north, east, and southeast aspects. We saw no other collapsing or cracking in wind slabs beyond our cornice fall. The snowpack under the wind drifts, and at middle elevations, still consists of faceted snow. Although the weakness of those facets seems to be more variable with time. The tide is even lower below 6000' than before Tuesday night's storm.
• Winds were from the south in the Swan Range today. We observed light winds above 5500' and moderate winds above 6000' but with only occasional and light blowing snow. The warm air and increasing clouds made the snow surface moist on all aspects below about 6000' today. As we headed down we could trigger small rollersballs.