A data storage system according to one embodiment includes a head, a drive mechanism for passing a medium over the head, a controller electrically coupled to the head, and logic integrated with and/or executable by the controller. The logic is configured to: update a first value based on a current position error signal sample, determine whether the first value exceeds a predetermined threshold, determine a stopwrite threshold based on the first value when the first value exceeds the predetermined threshold, determine whether the current position error signal sample exceeds the stopwrite threshold, disable writing when the current position error signal sample exceeds the stopwrite threshold, and enable writing when the current position error signal sample does not exceed the stopwrite threshold.