Crown Profile and Whumpfing on Proletariat

We investigated the avalanche crown on the Proletariat from March 17th (updated details in this observation) to determine if it was similar to the other recent avalanches in the Rose area that had failed on a graupel layer above a melt-freeze crust at the base of the recent storm snow. This avalanche appeared to have failed on the same layer. My partner anchored himself to a tree and he lowered me into the the crown. Snowpit tests at the crown of this avalanche yielded mixed results. However, as I was climbing back out of the crown while still on belay, I triggered a large whumpf and the slope above the crown collapsed but did not slide. The collapse / whumpf radiated out from where I triggered it about 20m upslope and 60 to 70 m across the slope. 

During the rest of our tour, we noted breakable crusts on any sun-exposed slopes and some runnels on an ESE facing slope at 9200 ft. and soft cold dry snow on the N and NE aspects. 

Snowfall up to 2 cm per hour started to happen around noon. It continued until about 1:45 pm until it started to change over to a light mist at 9100 ft.