Stiff whumpfs

At Four Lakes in the alpine today, while travelling on a steep south facing slope at 1800 m, we felt a whumphf and a shooting crack about 30 m long and 30 cm deep crossed the slope. This was failing on a 5 cm layer of facets on a hard crust, with a pencil hard wind slab on top. We didn’t see or trigger any other new avalanches but there were a few older (48hrs+) size 1 wind slabs from rock bands in extreme north/northeast facing terrain. We skied a steep north facing slope that had good turns - about 20 cm of soft snow over a hard crust. In a few areas it was wind affected with a breakable-to-skis thin wind crust on the surface. Winds were strong from the north this morning, but didn’t seem to be transporting much snow as everything had already been previously wind affected. They calmed this afternoon.