A system includes a control system. The control system includes a coherence derivation system configured to derive a coherence between respective outputs of each of a plurality of combustors coupled to a gas turbine system, and a phase derivation system configured to derive a phase difference between the respective outputs of each of the plurality of combustors coupled to the gas turbine system. The control system is configured to derive an indication of an impending lean blowout (LBO) or an actual LBO of at least one of the plurality of combustors based at least in part on the coherence derivation, the phase derivation, or a combination thereof.