1. A method for plasma processing of a wafer, comprising: positioning a wafer on a wafer support apparatus, the wafer support apparatus positioned beneath an electrode such that a plasma generation region exists between the wafer and the electrode; supplying radiofrequency power to the electrode to generate a plasma within the plasma generation region during multiple sequential plasma processing cycles of a plasma processing operation; operating at least one electrical sensor connected to the electrode to measure a radiofrequency parameter on the electrode during each of the multiple sequential plasma processing cycles; determining a value of the radiofrequency parameter as measured on the electrode for each of the multiple sequential plasma processing cycles; and determining whether or not an indicatory trend or change exists in the values of the radiofrequency parameter as measured on the electrode over the multiple sequential plasma processing cycles, wherein the indicatory trend or change indicates formation of a plasma instability during the plasma processing operation.