A method of receiving a substorm activity data log from one or more remote sensors, where substorm activity is due to solar activity. The method also includes receiving a harmonic distortion data stream from one or more remote observatories monitoring disturbances on a power grid, where the distortion is due to geomagnetically induced currents. The method also includes applying a mathematical model to the harmonic distortion data stream to create a derived harmonic distortion data log, and comparing phase-to-phase similarity of the three phases from the derived harmonic distortion data log. The method also includes predicting future adverse events due to geomagnetically-induced currents on the power grid based at least in part on the comparison and the substorm activity data log, and creating a warning based on the prediction.