After a hiatus the volcano began erupting pyroclastic flows, which were mostly constrained by the topography and were erupted in various stages interrupted by ash fall that extended to larger distances. Most of these pyroclastic flows accumulated in valleys radiating away from Huaynaputina, the flows reaching distances of from the vents. Winds blew ash from the pyroclastic flows, and rain eroded freshly emplaced pyroclastic deposits. Ash fall and pyroclastic flows alternated during this stage, probably caused by brief obstructions of the vent; at this time a lava dome formed within the second vent. A change in the composition of the erupted rocks occurred, with the Dacite 1 geochemical suite being increasingly modified by the Dacite 2 geochemical suite that became dominant during the third stage.