I know they changed the classifications of ENSO events based on the new climo. For example some years that are strong Nina...are now considered moderate based on the new climo given warmer SSTs. However, has anyone ever tried to use where the forcing is as a better proxy? What I mean is that stronger Ninas have a basic H5 pattern based on where the forcing is in the Pacific. In theory, I don't think that take should change because the new ENSO classifications call a prior strong event, moderate based on a few tenths of a degree Celsius of warming.
Lets say we have a neutral ENSO based on SST anomalies. However, 10 years ago this may have been considered weak Nina, and we currently have easterly wind anomalies as if it was a weak Nina. Something to think about.