Understanding how regional hydrological extremes would respond to warming is a grand challenge to the community of climate change research. A novel diagnostic framework based on the wave activity is developed for column integrated water vapor (CWV) to afford the probe into the higher moments of the hydrological cycle. Applying the CWV wave activity analysis to the historical and future climate projections from the CMIP5 models reveals that under RCP8.5 scenario forcing the wet-versus-dry disparity of daily net precipitation can increase at a super Clausius-Clapeyron rate due to the enhanced stirring length of wave activity at the poleward flank of the mean storm track, whereas the hydrological cycling rate (HCR) measured by the reverse of wave activity residence time decreases. The local variant of CWV wave activity reveals the unique characteristics of atmospheric rivers (ARs) in terms of their transport function and local enhanced mixing efficiency. Under RCP8.5, the local moist wave activity increases by ~40% over the northeastern Pacific by the end of the 21st century, indicating more ARs hitting the west coast, giving rise to a ~20% increase in the related hydrological extremes despite a weakening of the local HCR.