The team will explore the various physical drivers for the observed heavy rainfall events over the Hawaiian Islands. In particular, the team will investigate the individual and collective roles of both large-scale ocean-atmosphere processes and regional synoptic features. They include but are not limited to: (i) sea surface temperature anomalies in the North Pacific; (ii) atmospheric rivers; and (iii) Kona lows. To test overarching hypotheses, we will diagnose in situ and satellite-based observations for recent decades, in conjunction with designing numerical experiments with a high-resolution global climate model and apply suitable process-oriented diagnostics. The results will provide insight into the evolving rainfall characteristics over the Hawaiian Islands in a changing climate.