A wind forced ocean model is used to decompose the equatorial Pacific warm water volume (WWV) between 1980-2016 into the (i) instantaneous WWV response, which are the WWV changes due to winds prevailing during the previous 3 months consistent with WWV changes due to Ekman transports and (ii) adjusted WWV response, which is the WWV contribution of winds prevailing more than 3 months ago. Separate examinations of pre- and post-2000 periods reveal: (i) nearly equal importance of instantaneous and adjusted WWV responses for the pre-2000 period; and (ii) dominance of the instantaneous WWV response during the post-2000 period, due to a 44% decrease of the post-2000 adjusted WWV standard deviation (SD). Previous research showed that the increasing prominence of instantaneous WWV can explain the post-2000 reduction in WWV/ENSO sea surface temperature lead times (from 6-9 months pre-2000 down to 3-months post-2000). Our study focuses on understanding the apparent contradiction between the post-2000 decrease in adjusted WWV SD and the increase in instantaneous WWV SD as both are wind driven responses.